.408 CheyTac, .50 BMG ja .338LM

[MJ]

Moi kaikille,



tässä hieman amerikkalaista näkemystä .408 CheyTac:in, .50 BMG:n ja .338 LM:n ballistiikan vertailusta sekä niiden käyttötaktiikasta.



Lainaukset ovat amerikkalaisten koeampujien ja luotien valmistajien näkemyksiä (myös sotilaiden). Kukin lukija voi vetää niistä omat johtopätöksensä - korostan sitä, että kyseessä on nimenomaan amerikkalaisten näkemyksiä ja koeammuntatuloksia - sitä pitävätkö ne täysin paikkansa on vaikeata arvioida ja sanoa.



Miellyttäviä lukuhetkiä!



Carpe Diem,



MJ

.50 BMG ... First to the HTI point. HTI is NOT armor piercing. The impression that the .50 was an armor piercer is way out proportion. Yeah, a M82 rifle hit a BMP in the desert at 1850 yrds. IN discussions with the observer on that mission, they guessed at the range, and didn't know a thing about meteorological conditions... it was NOT struck on the first shot. Post kill analysis suggests that the fire that "killed" the vehicle was started as a result of sparks from the zirconium incendiary starting hydraulic fluid on the floor on fire. Hence smoke and running Iraqis. That track was NOT KILLED by an armor piercer.



The history of the Raufoss round is that it was NOT developed for the AP role. The true nature of the development requirement is still classified. But it's not for armor piercing.



With that little background, the true nature of the HTI mission as we worked on within US special operations is for "light skinned" strategic targets... here's a short list.



1) Strategic/tactical ballistic missiles.

2) Static air to air weapons systems and their controlling elements.

3) C3I vans and nodes.

4) "certain" components of radar systems.

5) Some components of electrical substations.



Never in the HTI profile was attacking armor on the list. The Heavy rifle mission was developed within the special operations community, not the conventional armor killing community. Even the EOD guys that dreamed up killing mines with their rifles have shelved that idea. Can't hit a sub MOA target with a 4 MOA Barrett gun.



Comment to the HTI mission for the .408. I agree with that. All of the potential targets that I have listed can be easily taken down with the CNC lathe turned solid bullet.



As for the anti-personnel mission on the .408. 2000 yard anti-personnel shooting is mostly a special operations mission. With that in mind, you wouldn't likely shoot at a target without a name/identifier. You probably would also know something about that targets physical characteristics. Do the tend to be fidgety? Do they stand still for long periods of time deep in thought? Do they rock back and forth on your feet?



Those answers to those questions will frequently determine the maximum possible shooting range, the rest being conditions and terrain. Careful target analysis of a target, any target, material or military personnel will yield information that will more likely determine the range at which you'll shoot vs. the met and env conditions.



Now, provided that you have a target that is very high value, doesn't fool around alot, or is an boxed in environment, the rest isn't too difficult. Special operations missions always are on the ground for an extended period prior to the raid/sniping/recon etc mission taking place. That period of time varies to around 24 or more hours... plenty of time to gather the data.



FYI on the test shoot, I took a ranging using the theodolite method that I had in the HTI book. Calculated for the meteorological and environmental conditions, dealth with a twitch 5-7 knot wind, and put three rounds into a 1.5 MOA group on the target... at 2300 yards.



Biggest trouble was the damned trigger... now have a Kipplinger set trigger on my Windrunner .50 and will have one on the .408.



Hope this didn't come across too cross... didn't mean to. Anti personal special operations long range sniping is 90% mission planning before getting on any aircraft. The rest is much easier.





First of all the rifle xxxxx was shooting was sub-minute of angle to 1900 yds. and minute and a half to 2300 yds. There were certain aspects to the rifle, specifically, trigger pull and chamber dimensions that will be improved on the production models. We fully expect an accuracy improvement.



Second, even with that rifle xxxxxx was able to put his first rounds in a 60" x 20" box out to 1900 yds. When the scope based was machined to center up the optics he put his first shot at 2300 yds. in that box. Most of the errors were wind induced horizontal and the winds were squirrelly. Part of a shooter's responsibility is to determine if a shot should be taken. There were numerous times when the wind allowed a shot and many more times when it was not possible. But the main point is that 2300 yds was the maximum operating range during this test. At 1600 yds., where other cartridges are stretched, the 408 CheyTac is right in the middle of it's power curve.



Machined solids are going to punch right through soft or lightly armored targets. After about eight to ten inches of penetration in tissue it may destabilize and cause a cavitation hole about the size of a canteloupe for about a foot, but this is depending on velocity, angle of attack, and the density of the tissue struck. At 1500 fps. and below there will be little or no expansion from any solid or lead cored bullet. At these low velocities there is no secondary wave effect damage and only the primary wound channel, slightly more than 1 caliber, will be left. It is a 40 caliber bullet traveling at supersonic speeds and will be reasonably lethal, especially on relaxed targets. Targets that have their adrenline pumping are something else, again. On high value material targets they would be evaluated such that one or two 40 caliber holes through them would be the requisite amount of damage.



Remember, capabilities dictate tactics, not the other way around.



yyyyy's got a good point on "relaxed targets". Living targets, animal or otherwise display different "die" characteristics when struck with bullets. Living targets that are relaxed and comfortable with their surroundings, such as a bad guy deep in his own territory with good security will drop easier than a combat infantryman that is pumped up, running around dodging bullets.



Colonel William Fackler, US Army wound ballistics guy said that of the 4 factors that determine a killing wound or shot, the one factor that is the most important and you CANNOT determine or control is the psychology of the target. To put it short, you just never know.



Fackler also did some research on why so many soldiers is WW1 and WW2 and other wars for that matter died so easily. They have seen some captured by the combat camera where there were hit with a non-instant killing shot, but they hit the ground dead. There is a famous WW1 film clip about a guy running, being shot, tossing his rifle high, and dieing while falling. Col Fackler explains, "they die because that's what they're supposed to do".



In other words, in training, they were constantly told that if they don't properly hide, conceal, seek cover, they get seen and hit and therefore die. He's suggested it was a psychology issue. "They die becaused they are told that they will, if hit". Many doctors say that the difference between living and dying from trauma is in the will to live.



Dr. Fackler also said that there are only three trauma type factors that kill soldiers on the battlefield, or in trauma injuries for that matter.



1. CNS shutdown type injury (brainshot, massive damage to the head, etc).



2. Loss of blood (heart shot, major arterial bleeding, traumatic amputation, etc)



3. Shock, from the injury to the system.



4. The final and most important factor that leads to death in trauma damage is psychology of the person being hit / wounded. The one that you cannot possibly control.



That's why a deer struck on day one early in the that first day will go down nearly all the time with just about any shot. That's a death due to shock more than the trauma, unless it's a true killing shot.



One that's similiarly struck on day 7, after being shot at several times a day, low on food, and hiding, is likely to have to be tracked a while unless he's shot to the CNS or heart area. Lungs or guts, prepare to follow.



The arguement being, that merely poking a hole is usually enough, especially from a 419 gr. bullet going 1200 fps. Remember that the .45 slug does well and it's weinging 230 gr. at 800 fps or so. I'll have to see if I can dig up Col Fackler's report and post in here.



Ultralong Range Trajectory and accuracy is where the .408 CheyTac is unparalleled. The 338 Lapua will come up short no matter how we manipulate velocity or BC, as will the 50 BMG. There are some 30 caliber options that may result in flatter ultralong range trajectories, but they all are in barrel burners and the bullets are not wide enough nor heavy enough for most material applications. The .408 CT has more punch,than the 338 LM., which is important against masonry. As for lethality the .408" diameter bullet will be superior to the .338".



The .408 CT is a large jump in the effective range of small arms, so much so that some of the support equipment will have to be improved to keep up with it. Here's an update on the development of the .408 CheyTac. Some of you may know that the gun is being built by EDM Arms. It is a scaled down version of the Windrunner .50. The design team is meeting next week in Arco Idaho, the home of Lost River Ballistics to do final bullet testing for two bullet weights. 305 gr. for Battlefield Domination (big word for more conventional "defensive" operations), and a 419 gr. for extreme range unknown distance shooting.



The light bullet is intended to use to cover medium ranges up to 1100 - 1200 meters WITHOUT the need for range determination by using the method "Reverse Image Zero". BY using this method, target ID time to engagement time is less than 10 seconds, not the 1 minute standard that is common in US schools on sniping.



The heavy bullet is supersonic for 2200 meters +. They are both CNC turned solids of VLD design. These rifles are for sale with a 90 day turnaround time. Sierra has stated that they will make lead core standard design bullets once we finish with the solid design and they have something to follow on.



This will obsolete the .338 Lapua, .338 RUM and other mid range cartridges. In computer analysis, the .408 CheyTac heavy bullet cartridge is supersonic further than a .50 BMG shooting the 750 gr. AMAX bullet (BC 1.000+), and super sonic range is what it's all about.

The case is based off of the .505 Gibbs case. It has a .635 case head size and the case is 3.25" long. OAL with the 419 gr. bullet is 4.515"



The 419 gr. bullet is a CNC lathe turned copper / nickel bullet. The projected BC off of the PRODAS program is .900. Our range testing next week will give solid BC data back for ranges to 2700 yards or more. We will be shooting the gun to supersonic max range and into the sub-sonic range.



The rifle is currently built by EDM arms and it is a scaled down .50 Windrunner. The size of the cartridge dictates a larger than standard magnum length action. The McBros Talon, Dakota Safari, and Hall Express ( I think ) will handle the cartridge. We are also doing a 305 gr. bullet for a certain tactical application.



Upon approval from the design owner, Dr. John Taylor and completion of next weeks work, I will be able to release a sensitivity analysis of the .408 vs .338 Lapua and .50 BMG using military and AMAX loads. I have the predicted data right now and won't release it until it's proven data.



.408, the project has spun into 3 additional technologies besides the .408 CheyTac platform.



1. Advanced Ballistic Fire Control Computer with autotmatic input for all environmental and meteorogical conditions as well as internal ballistics variables such as ammo temp, varying velocities etc. The device will have built in sensors for air pressure, air temperature and automatic inputs for winds at the gun position and direction. The operator will have the option to input values for downrange conditions. Remote wind sensing is in the works also.



2. GPS offset rangefinding. Details are classified. Range determination solution will be sub meter at 2000 meters and the system is totally passive. The range data will be automatically fed into the fire control computer.



3. Advanced technology projectiles from Lost River Ballistic Technologies. These are the 419 grain .408 caliber bullets that are showing to actually GAIN downrange BC value.



4. US Optics long range optical sight system. This is an externally adjusted sight with high resolution lenses.



In my opinion, having shot all the tactical big bore guns, the .408 obsoletes the .338 Lapua and the .50 BMG in all areas except explosive projectile delivery. The .408 is supersonic past the BEST 338 Lapua bullet by over 400 yards and the BEST 50 BMG bullet (anything with a 1.000+ BC) by 500 yards or more.



Determining whether 2000 meter shooting is feasable is a reasonable arguement. In my opinion, major resolving issues are:



1. Range to target. This is dependant on danger space. Danger space of a shot against a 2 MOA target at 2000 meters is the same as the danger space for a 7.62mm system at 700 meters. WE've all done that, not too tough. GPS rangefinding makes that easy, and you don't have to have a target to make it work, just something, anything to point a system at.



2. Resistance to windage deflection. Since you can't get the winds right ever, unless you have remote wind sensing technology (which we will have), the efficiency of the bullet against the wind is a major factor. Lost River Ballistics has mastered a form of bullet design that achieves "balanced flight". Can't say anything else about it. Classified at this point, and under patent approval.



3. Nature of the Target: To us at this point, this is the most determining factor. We can overcome 1 and 2 above. If the target is fidgety and moves around alot, that determines how far away you can shoot him. If he's a relaxed, thinker type that stands in one place alot, he may be engagable from greater distances.



PS... the fire control data will be generated using Weibler Doppler radar and acoustic microphone data obtained at extensive testing at Yuma Proving Grounds later this month. This is the best data available as the actual downrange performance of the bullet is tracked in flight. All other programs on the market, even the current best, use BC data that is provided by manufacturers or by shooting bullets through screens at shorter ranges. The bullets that we test, will be shot to MAXIMUM ranges, 6000 yards+. We will have downrange velocities and spin data from 0 to 6000 yards plus, actually as far as the bullet can fly.



The Yuma test results showed that across the board, the Lost River Ballistic Technologies bullets are superior to every other bullet tested. For the .338 Lapua shooters, get the 270 gr. bullet, it's BC sneaks up on .9 and you can push them at around 3000 fps. I got 3100 fps on a Dakota Arms Longbow gun. The .50 LRBT bullet has a 1.000+ true BC value and it also gains BC at long ranges and was the ONLY bullet to remain stable in transonic flight and remained stable in subsonic flight.



I believe that we have two unofficial world records at 1500 and 2000 yards, see test results. Check out the J40 bullets at http://www.lostriverballistic.com">http://www.lostriverballistic.com.



Actually, that's an easy. It's in the shot groups. If you can put a group on a target of 1 MOA, I think that's reasonable to assume that shooter induced stuff is NOT the case. Using the creeping in method, by shooting groups at ever increasing ranges under great conditions, there is a point at which mechanical errors show up.



With a 15" group, and we've repeated MOA capability at that range several times, when you step to 2500 yards, the MOA potential should stay roughly the same, all conditions being the same. Determining the mechanical error on the scope at that range was easy.



1. The group opened up to nearly 1.5 MOA.



2. We were at the top of the elevation travel on the scope.



3. We all know that when aiming through an internally adjusted scope, and you are at the the extremes of travel (elevation or windage) you are encountering optical vignetting,,, distortion.



When we changed by base angle so that 2500 yards was IN the capability of the optics, we were at 1 MOA again. 3000 yards was the next hurdle. When we recieve our US Optics advanced sighting system, you'll see our grouping go under 1 MOA at 3000 yards or more at those conditions (supersonic) + some.



The fire control computer is much more than a palm pilot. It's using integrated data from our Yuma Proving Grounds shoot in front of their Weibler radar system. I dare say that it is the most accurate and usable data on military and civilian sniping cartridges/bullets in the world at this point. It cost alot to get that information. We have downrange BC values on all drag curves for EVERY military issued cartridge in the US and several overseas countries.



The Lost River Ballistic Technologies J40 match bullets prooved to be the slickest and cleanest flying bullets available. No one else came close, not even a little close. The 270 gr. LRBT .338 match bullet was supersonic 350 yards farther than the 300 gr. Sierra bullet, and remained much more stable through transition into sub-sonic flight.



I can't release many details on the data or the capabilities of the computer. The data can be corrected to within .10 MOA at ranges to 5000 yards, and can be operator tuned so that individual gun system inputs can be added to the data, making the software "smart" and capable of learning each shooter's input tendancies.



The Idaho III test was done to test the OPSINC suppressor and the initial version of the fire control computer (which by the way works for any caliber that we shot in Yuma Proving Grounds).



The suppressed gun shot under 1 MOA all the way to the test range of 1500 yards for the suppressor work. Time limited us to this range as we could not go any farther. Once the pictures are posted in the photo section, you'll see how the can is mounted to the barrel. The suppressor gains about 30 fps muzzle velocity over the standard brake and retains or gains accuracy over the standard system.



The suppressor also repeats it's zero perfectly when taken off and replaced. This was tested over and over on the 25th of August to determine it's repeatability and durability. She gets hot though, as do all suppressors. The OPSINC suppressor is all stainless steel construction and has no wear out point, there are no replacable baffles, etc in the can. It is designed to be drained in less than 6 seconds when fully submerged and tipped muzzle down to drain. The suppressor can be fired after the initial flush is done.



The suppressor is the quietest that I have tested on a long range rifle. Recoil is very mild as with the standard brake and watching bullet impact at 200 yards is easily done. At long ranges, 600 yards and more, a shooter can easily correct his own left and right errors by watching for bullet impact. You do not loose sight of the target under recoil. That's true with the McArthur brake also, but dust is kicked up by that brake.



The fire control computer (software was installed on a HP Jornada 525 for testing) worked as predicted also. We used field data taken from our Yuma Proving Grounds tests for downrange information. This method uses NO curve and extracts the exact BC or drag co-efficient value for the range entered. It is then corrected for conditions.



Elevation data was tested to 2000 yards at times of the day when maximum conditions fluxuation were in effect. From 4:00 am to 6:00 am at the test site, the air temp chagned +20 degrees. A new calculation and shots were done every 15 minutes. Vertical impacts were within .10 MOA (measured from point of aim to center of the group).



The Lost River Ballistic Technologies M40 bullets have very little precession, requiring about 10% the spin rate correction of the conventional bullets (Lapua, Sierra, and everyone else). That required a tweaking of the spin correction formula. Also tested were the corrections for Coriolis or the earth's rotation. For those that don't think it's an effect, IT IS. Misses will occur at 1500 yards or greater on certain points on the globe if Coriolis is neglected.



The bullet's resistance to wind deflection also required a tweaking of the standard wind formula. A critical part of that formula is true flight time to the target. The LRBT bullets however, do not fly as other bullets do and using the standard formula results in overcorrections. That is also fixed.



At this point, we are moving forward with Version II of the software. The projectiles will be offered in two versions. The J40 version is for the civilian market and is a softer alloy. The flight characteristics are the same. The M40 projectile is for the military application, having a much harder material. The J40 leaves no copper fouling in a broken in barrel and is easy to clean.



Velocities will be 3000+ on the production guns based on tests. I know this sounds dry and clean, sorry, not much time. Have to get ready for another trip. More to follow, check out the pictures.



The specific question is, what are the practical limits of elevation determination using commercial GPS units. Will I be able to get close enough on elevation at the target site and FFP site to calculate a valid slope value?



With regards to long range winds, something the .408 project has been dealing with extensively.



Winds frequently are not only different direction, but different velocities as well. Not only that, but the higher the maximum ordinate, the greater the velocity AND effect of the wind at that altitude. Here are some examples.



Recent out of country trip to train guys on anti-material interdiction using .50 BMG rifles. Our computer fire control system for the .408 addressess all US military sniping cartridges from 7.62mm to .50 BMG and some specials along the way. There are 3 points of entry for winds 1. at the gun, 2. at midpoint or max ordinate range, and 3. at the target.



All are weighted differently based on a rather large data base on information gained in testing using Doppler radar. In one situation, shooting at 1625 yards, we had winds at the gun at 12 kph from 7 oclock, winds at mid range to target of 25 kph!!, yep 25 kph from 9 o'clock, and winds at the target of 30 kph, from 11 oclock.



The guys were very good at looking at terrain features, studying wind and weather patterns for the surface and using that data to put in the 3 different wind variables. Needless to say, if you would ignore any of the 3 conditions stated, a miss would occur. Can't say the nature of the targets, but they were slightly wider than the average human being, when talking about wind, height doesn't matter, i think.



Based on 2 years of testing, we've determined that you can read down range winds and integrate that information with terrain analysis as zzzzz mentions. I agree with him on that. For most situations shooting .308 guns to 600 yards or so, downrange winds are not likely to be different velocities, but as he also says, they can easily be in different directions.



Here's an old arguement... winds at the gun being the most critical. I understand totally the point mentioned about a bullet picking up a crosswind velocity, then carrying that offset all the way downrange. In my opinion, the bullet must be exposed to those "winds at the gun" values for at least 1/3 the flight distance before those winds mean more than the winds downrange. In fact, that's more than opinion, that's fact proven in testing.



Here's an example, ever shot from a hovering helicopter at a target 300 yards away? The downwash at 150mph from a hovering helo suggests a windage correction of 12.64 minutes of angle using our computer. These are proven figures,,, BUT, it doesn't work like that. The real deflection over that range is only about 2-3 minutes of angle in those conditions.



Why? Again, this is not a guess, it's measured. The rotor wash isn't pushing the bullet long enough, or the bullet isn't exposed to that 150 mph wash long enough to offset the 12.64 minutes the computer says it should be. We've been doing the long range wind game for a couple of years then integrating that into the computer for the .408 system.



Is this computer good? Well two major CT units in the world are now using them. Not a sales gib, but they are working and working well. I know this adds fire to the discussion, just observations.



The first day's activities wrapped up with a demonstration of the .408 CheyTac's long-range capabilities. The unique sniper system has posted a five-shot, five-inch grouping at 1,531 yards. Interested in upping the ante, company representatives said they were ready to demonstrate the system's accuracy during the Shoot-out at any unknown distance out to 2,500 yards.



All of the first day's shooting took place on Blackwater's long-gun (1,200-yard) range, the longest known-distance range on the facility. To accommodate the CheyTac team's request, our group moved to a spot several hundred yards beyond the limits of the 1,200-yard line.



After feeling out a few potential shooting positions, CheyTac's marksman settled down on a spot from which his target, an 18-inch glass panel, was barely visible to the unaided eye. Using a Cassiopeia Pocket PC with an integral laser rangefinder, he determined the target was about 1,700 yards away. He then fingered the control panel on the PC, which quickly computed a ballistic firing solution based on wind speeds and direction at three points between the weapon and the target, the ammunition's burn rate, and effects caused by the earth's rotation. With that information, he turned the weapon's sight's windage and elevation knobs to the positions indicated on the PC, and let loose the first of five rounds - a 419 grain slug - from an Intervention Model 200 Military system.



An intermittent wind was now kicking up dust between the shooter and the target, bringing with it a threatening sky. Four more rounds were sent on their way over the next few minutes; each was preceded by a new reading on the PC. ..... later learned that, according to the wind readings from the PC, during the course of the five-shot sequence the wind direction shifted 180 degrees and kicked up to 18 mph.)

With the last shot, the group headed downrange. Two hits were visible in the glass; a third round had torn through the frame holding the pane. All things considered, not a bad showing.



The CheyTac .408/Ballistic Computer combination is truly a unique shooting system. In its military version, the computer carries ballistics data for all commonly used U.S. military cartridges plus the .408 and the .338 Lapua. In the alternative "civilian" version, the computer is loaded for various other cartridges.



CheyTac offers both military and civilian target/law enforcement long-range systems. The Intervention Model 100 and Shiloh Model 300 are designed for target and law enforcement use; Intervention Model 200 and Shiloh Model 400 systems are designed for military applications. All are chambered for the .408 cartridge, which is available in 419 grain (2,950 fps) and 305 grain (3,500 fps) versions.



The rifle's action features a removable bolt head that can handle groups of cartridges with the same cartridge rim diameter. The bolt for the .408 CheyTac cartridge, for example, has a 0.6402-inch rim; therefore, it can handle cartridges spanning from the .300 Kong and .338 A-Square to the .505 Magnum Gibbs and .585 Nyati.



After watching the first day's shooting from behind the firing line, the evaluators were ready by their second day at Blackwater to get their hands on the impressive hardware arrayed on three of the facility's ranges. A CheyTac .408 Intervention Model 200 was among more than a dozen weapons aligned on the midway point of the 1,200-yard range.



Outfitted with a Nightforce 5.5-22-by-56 NXS scope, and wearing an OpSinc suppressor with a mirage-defeating thermal cover, the 27-pound rifle was ready for the day's business. A 30-inch, fluted match barrel, nestled in a free-floated barrel tube, accounts for more than half of the weapon's overall 55-inch length (with its retractable stock extended).



It came as no surprise that the M200 rated consistently high marks from all who fired it. "I didn't want to let go of it," one wrote, "this weapon touched my ergonomic roots!" He went on to note that the system delivers "superb bolt-action firepower at long ranges." He found loading and unloading "smooth and easy," and the weapon's recoil "acceptable - I had expected more. Truly a pleasure to shoot this magnificent firearm."



His colleagues were equally effusive. "An extremely pleasant shooter," another noted. "Soft recoil for its capability. Superior to the .50 BMG for most precision applications. The suppressed gun was impressively quiet, and I'm very impressed with the ballistic computer integration."



Noted another, a bit more succinctly: "A sweet-shooting rifle. Low recoil makes it easy to get back on target and maintain control."



The only negative concerning the .408 CheyTac concerned the location of the weapon's safety. He found its positioning (above the trigger, about an inch from the closed bolt handle) "a bit awkward."



A CheyTac spokesman later told that future improvements being considered for the system are likely to include a change to the weapon's safety.

[HJu]

Mielenkiintoista tekstiä. Ballistisesti .408 Cheytac lienee aika hyvä vaikka tähänastiset testiselosteet mitä julkisuudessa on liikkunut, ovat olleet käytännössä vain Dean Michaelisin ja John D.Taylorin kirjoittamia testituloksia.



Dean Michaelis on .50 BMG tarkkuuskiväärien ex-käyttökouluttaja USAn erikoisjoukoille  josta on tullut .408 Cheytacin markkinointimies ja John D. Taylor on yliopiston professori joka ihastui ensin .338 Lapua Magnumiin mutta sitten jotenkin pettyi siihen kun se ei ollutkaan oleellisesti .50 BMG:tä parempi eikä edes aidosti "intermediate" 7.62 Naton ja .50 BMG:n välillä. Koska Taylor oli uskollinen tälle ajatukselle että 7.62  Naton ja .50 BMG: n TASAn puolivälissä pitää olla kaliperi niin hän kehitty .408 Cheytacin. Eli John D. Taylor on keksinyt/kehittänyt 408 Cheytacin. Nyttemin mainostekstien mukaan .408 Cheytac onkin kehitetty täyttämään "aukko" .338 Lapuan ja .50 BMG:n välissä. Taylorin vanhempia tekstejä lukiessa havaitsee että ainakaan alunperin tätä ei haettu vaan koitettiin keksiä 338 LM:ää parempi kaliperi kivääriin. Lopputulos on hyvä kaliperi mutta .50 BMG:n kokoisessa aseessa.



Ongelmia:

- Aseita valmistaa yksi yhtiö, Cheytac, hinnat alkaen +7000 USD ilman tähtäimiä (ei mene kaupaksi koska monopoli estää kilpailuttamisen, ilman kilpailuttamista armeijat ei osta juuri mitään)

- Hylsyjä saa VAIN Cheytacilta (monopoli ja monopolihinnat ei miellytä ketään)

- Luoteja saa toistaiseksi vain Cheytacilta (valmistaja Lost River Ballisticsilta 1,5-2 USD kappalehintaan)

- Latausholkkeja saa vain Cheytacilta

- Valmiita patruunoita ei saa periaatteessa mistään mutta käytännössä ilmeisesti LRB:ltä ja Cheytacilta sotilastilauksina

- Aseiden koko ja paino vastaa kevyempiä .50 BMG-kiväärejä: 12,25 kiloa ilman tähtäimiä ja patruunoita, pituus 1220mm tukki kiinni asennossa ja käyttökunnossa 1397mm. OPSINCin vaimennin lisää painoa pari kiloa ja pituutta 350-400mm. -> Lopputulos painaa vähintään sen mitä mikä tahansa sotilaskäytössä oleva .50 BMG.



Sotilasteknisesti Cheytacin erityisongelmia ovat:

- A-tarvike koostuu pelkistä solidiluodeista. Ne eivät räjähdä eivätkä muutenkaan tee reiän lisäksi paljon mitään materialle, tutkakuvussa siisti reikä on siisti reikä oli se ammuttu 2300 yardin tai 800 metrin päästä. Usein se ei edes vaikuta tutkan toimintaan mitään.

- Ase sen enempää kuin kaliperi eivät ole yleisesti käytössä tai tuotannossa, A-tarvikehuoltoa ei siten pystytä järkevästi järjestämään

- 1,5 Moan tarkkuus 2300 Yardissa on ihan kiva, vielä kun se kasa pysyisi aina samassa paikassa :-), tuuli vaikuttaa tuohonkin luotiin niin paljon että ongelmia ja ohilaukauksia on tiedossa

- 2300 yardin, tai edes 1500m kantamia harvemmin kivääriaseessa tarvitaan koska aavikoita ja vuoristoa lukuunottamatta harvoin on suoraa näkyvyyttä noin pitkälle, toki erikoistilanteita on mutta niihin on usein käytettävissä muutakin kalustoa kuten lentokoneita, ohjuksia, tykkejä jne. Tavallinen luoti ei myöskään noilta matkoilta kovin isoa tuhoa tee.



Lyhyesti summattuna kaliperi voi olla hyvä kaliperi jos ammutaan elävää voimaa kiväärillä ylipitkiltä +1500m matkoilta. Se vaan harvemmin on oikeasti tarpeen.  -> Ihan hyvä konsepti jolle ei oikein tunnu löytyvän käyttötarvetta. Eipä näitä vermeitä juuri ole hankittu edes USAn sotavoimille. Erikoisjoukoilla lienee käytössä näitä jonkin verran mutta aika spesiaali kohde pitää olla että sitä on pakko ampua kiväärillä yli 2000 metristä ja jonka takia kannattaa pelata ei-standardeilla aseilla ja a-tarvikkeilla.



Siviilipuolella kaliperi ei monopolihinnoittelun ja valikoiman vähäisyyden vuoksi ole ainakaan toistaiseksi edennyt yhtään mihinkään eli niitä ei osteta eikä niillä kisata esimerkiksi pitkän matkan tarkkuusammunnassa käytännössä ollenkaan.

[Chillie]

Itse tuossa taannoin asiaa tiedustelin eräältä patruunapesän kalvaimien valmistajalta, ja kyllä niitä tuntuu olevan Custom pohjalta saatavaan...

Ja kylläpä niitä noita muitakin komponentteja saa jos näkee vaivaa etsiä/valmistaa...

Toinen asia on sitten kuitenkin se että kannattaako..

Ainakaan meillä ei vastaavalle patruunalle ole, kuten edellisessä mainittiin, käyttöä.

.338 ja .50 toimivat ihan hyvin...





S

[MJ]

Moi,



Viimeistä amerikkalaisten .408 Cheytac infoa Irakista.



Miellyttäviä lukuhetkiä.



Carpe Diem,



MJ

New sniper rifle makes debut in Iraq war zone

Weapon shown to hit targets at 2,400 yards



By Laura Bailey

Times staff writer





While Marine snipers using the M40A3 sniper rifle in Fallujah, Iraq, are

touting the Corps' longest confirmed kill in Iraq at 1,050 yards, an Idaho

arms company says its weapons can - and are - shooting farther in the war

zone.

A small number of CheyTac M200 Long Range Rifle Systems have made their way

to Marines in Iraq through U.S. Special Operations Command, said Robin

Sharpless, senior vice president of the Arco, Idaho-based company.



While the weapon is known to have fired accurately at distances beyond 2,400

yards in numerous field demonstrations in the United States, there also are

unconfirmed rumors that it is performing similarly in operational situations

in Iraq.



Sharpless would not disclose the number of rifles in theater or who

specifically has them, but he said the weapon is rumored to have been used

to kill Iraqi combatants at distances of 900 to 2,400 yards.



Military officials in Iraq did not respond to a request for comment by Jan.

21.



With accurate shots at such distances, Sharpless said the CheyTac rifle is

bound to dramatically change sniper standards, possibly giving the Marine

Corps "command and control decapitation" capabilities at greater distances

in the future.



"A $4 bullet could now do what an F/A-18 would take," he said. "That's a lot

cheaper than an F/A-18 and a laser-guided bomb."



The company touts the weapon's .408 round as having an especially smooth and

stable flight capability, allowing it to travel farther.



"We've identified a system to identify, quantify and mitigate the factors

that affect a bullet's flight," Sharpless said.



But the bigger punch comes with a tradeoff in weight.



At 27 pounds, the CheyTac is a bigger load than the M40A3, which fires a

7.62mm round and weighs 16.5 pounds. And that's just the rifle itself.



Beyond the rifle, the CheyTac package includes a hand-held computer system

that calculates elevation and windage and provides the operator with

appropriate settings, such as correction for air temperature and air

pressure.



The system also includes an infrared laser; a sensor package to measure

wind, air temperature and air pressure for feeding into the hand-held

computer; a laser range-finder; and a wrist computer that provides

environmental data. It also features day and night optical systems.

[mpmasa]

Cheytac:in sivuilla on 6kpl sarja noita nato malleja,

että luultavasti sen verran nuita on kenttä testeissä.

Siinä vaan on varmasti pitkä aika siihen että laajemmassa mittakaavassa tulevat olemaan kenttä käytössä.



Kuvia löytyy

http://www.cheytac.com/">http://www.cheytac.com/



Asehan on pikkusen pienennetty versio Edm Arms:in windrunnerin 50bgm versiosta.

Jatkokehittelynä ollut osien muuttaminen kenttä kelpoisemmiksi ja lisätty tarvikkeita valmiiksi.

http://www.edmarms.com/">http://www.edmarms.com/



sinänsä mielenkiintoinen asemalli ja jotain uutta perinteisiin verrattuna

[HJu]

Pelkkä kivääri+bipodi+tähtäinkisko 10995 USD. Siihen tähtäin ja muut hilut (laser +2000m matkoille, valonvahvistin yms.) päälle tuplaa tai triplaa asejärjestelmän hinnan. Voi se olla hyväkin, noilla hinnoilla kuitenkin aivan sama näin harrastajalle.



Selvittelin huvikseni asiaa ja piippuja saa moneltakin valmistajalta, luoteja voi sorvauttaa teoriassa missä vaan. Hylsyt taitaa olla ongelma. Patruunapesäkalvaimia toki saa mutta ei ne mitään erityisen halpoja ole. Lisäksi kaliperi ei ole sen enempää SAAMI kuin CIP-määritelty joten pientä ongelmaa voi olla kalvaimen oikeiden mittojen haalimisessa. Joku ne kalvaimet tietty Cheytacillekin tekee joten kyllä se tieto jossain on.



Windrunnerin idea on mielenkiintoinen mutta kyllä siitä väkisin aika kallis tulee kun joka osa tehdään CNC-työstöasemassa.



USSOCOM voi noita hyvinkin käyttää tai testata. Siitä on pitkä matka että noita ostetaan enemmän kuin kourallinen tositoimiin. Jos katsotaan USAn sotajoukkojen ongelmia lanseerata edes 300 Win Mag ta-kaliperiksi yleiseen käyttöön tai ongelmat järjestää laadukasta a-tarviketta .50 BMG-kivääreihin niin kyllä aikaa vierähtää vielä tovi ennen kuin .408 on minkäänlaisessa vakiokäytössä missään vaikka se olisi miten hyvä.