Ampujalegenda David Tubb

[MJ]

Moi,



David Tubb ampui vapaalta kädeltä pisimmän osuman 1605 jaardiin eli n. 1468 metriin viime vuoden lokakuussa NRA:n Floridan High Power kilpailussa. Aseena hän käytti itse suunnittelemaansa Tubb 2000 pulttilukkokilpakivääriä (hybridi AR-10:stä ja pulttilukkokivääristä) ja patruunana uutta 6mm XC patruunaa. Uudesta patruunasta povataan (ainakin Jenkeissä) jättimenestystä, joka kompensoi niin 6,5 - .284:n, kuin 6mm BR:n ja siinä sivussa muutkin (6mm PPC, 6,5mm Grendel, 6.8mm SPC ja 6,5mm JHC). Joka tapauksessa mieletön suoritus Tubbilta – siinä haastetta itse kullekin.



Ohessa taustaa David Tubbista ja 115 grainisesta 6mm XC:stä.



Miellyttäviä lukuhetkiä, sana on vapaa, mielipiteitä, näkemyksiä & kommentteja!



Carpe Diem,



MJ





DAVID TUBB:

11 Time National High Power Rifle Champion -- 1985 -86-88-90-91-93-97-99-01-02-03 Held annually at Camp Perry, Ohio, the NRA Highpower Rifle Championship consists of shooting three 80 shot matches at 200, 300 and 600 yards. Positions are standing, sitting, and prone. (Only person to win this event 11 times.) David also holds the Camp Perry Championship Record at 2389-138X (2400 possible) as well as the National Record on a single 80-shot (Regional) course of fire of 799-50X (800 possible).



National Highpower Long Range Champion -- 1984 -85-86-87-88 Held annually at Camp Perry, Ohio, this event is fired at distances of 600, 800, 900, and 1000 yards.



Wimbledon Cup Winner 1986 Also held annually at Camp Perry, the Wimbledon Cup is like a separate National Championship unto itself. The match is 20 shots for record, any rifle, any sights, fired prone at 1000 yards. Followed by a shoot off by the high scoring competitor on each relay to determine the winner.



National Highpower Rifle Silhouette Champion -- 1987 -88-89-90-91-92-93

This event is fired at distances of 200,300,385 and 500 meters at metallic silhouettes of animals. All firing is done offhand. Three 40-shot matches constitute the championship aggregate (120 possible). (Won this event 7 times in a row.) Culminated by the last win in 1993 using a FACTORY Remington 700 against the custom "chin guns" that David pioneered. This is akin to winning the Indianapolis 500 with a stock Corvette. This experience more or less "closed the door" on David's Silhouette Championship run: not much else to prove! National Championship Record 110x120  National Championship 40-shot Course 38x40



National Highpower Hunting Rifle Silhouette Champion -- 1985-86-88-89-90-91-92-93 This event is fired at distances of 200, 300, 385 and 500 meters at metallic silhouettes of animals. In this event the equipment is limited to an off the shelf rifle. National Championship Record 103x120 National record 40 shot course 35x40



National Smallbore Rifle Silhouette Champion - 1988 This event is .22 Rimfire fired at 40, 60, 77, and100 meters at metallic silhouettes of animals. Three 40 shot matches constitute the championship aggregate.



National Smallbore Hunting Rifle Silhouette Champion -- 1988-89-90-91 This event is .22 rimfire fired at 40, 60, 77, and 100 meters. Three 40 shot matches constitute the championship aggregate. National Championship Record 108x120



Chevrolet Sportmans Team Challenge National Champion -- 1995-96-97-98-00-01-02 This NSSF Event is fired annually with 3 person teams. All participants use rifles, pistols, and shotguns in different events. Aired in the fall on ESPN.



1997 Rifle Masters tournament champion 1998 National Shooting Sports Foundation (NSSF) Shooter of the Year In Summary, David has taken 37 Open Individual National Championships. This does not include individual matches, aggregates or team title which number in the hundreds.



David has been involved in over twenty commercial videos on the topics of shooting techniques and reloading. He, of course, wrote "Highpower Rifle," a book on across the course rifle competition. This book was published by Zediker Publishing and available for sale elsewhere on this site. David designed two different competitive rifles (both of which bear his name) and has been instrumental in creating many different, innovative, and successful products for the serious rifleman. His knowledge of firearms ergonomics is unsurpassed.



David was self-employed in the steel tubing business for 15 years and currently owns and operates Moly Coatings Inc., the industry leader in custom bullet coating technology, and Superior Shooting Systems Inc., a provider of innovative and effective high performance rifle parts and accessories. 48 years old, married, four children (including some Camp Perry winners!)

6mm XC patruuna:

Basics of Tubb's New Cross-Course Cartridge



Cartridge Origins -- by David Tubb (11-time NRA High Power National Champion) The 'original' 6mmX (20-degree shoulder) resulted from chambering a barrel using a .243 Winchester reamer held (stopped) 0.132 inches short of its intended depth. This was done to allow use of a .22-.250 case. The 6mmX sizing die was made by shortening a .243 Winchester die (seating die also) 0.145 inches (additional length was based on varying shellholder heights; this ensured the case could be run fully into the die and attain adequate case shoulder contact). We then took a .22-.250 case and ran it fully into this sizing die and then loaded the rounds and fire-formed the case in the 6mmX chamber. The .22-.250 case neck could initially be expanded using the sizing die provided a tapered (.17 cal. to 6mm [.243 cal.]) Redding expander was installed or that the expander had been modified with a taper. The 6XC (30-degree case shoulder) cartridge came about as a natural progression from shooting the original 6mmX. The 6XC has some features which I feel are more desirable compared to the 6mmX. ·  The cartridge case body length is 0.023" shorter than the 6mmX. This means that a 6XC chamber reamer now cuts the base of the case closer to the original .22-.250 base diameter.·  Shortening the case body also allows for less longitudinal (length) stretching during fire-forming. This will result in the 6mmXC having a greater case life (more firings).·  The 6XC's 30-degree case shoulder retards case growth (less trimming required).I have found that velocities attainable with the 6XC are equivalent to those attainable using .243 Winchester. Barrel life is much better than .243 Winchester due to the fact that the 6XC has about 7 grains less powder capacity. 6XC Cartridge Specs and David's Suggested LoadsA New Bullet Makes a Good Cartridge Even BetterThe new 115gr 6mm from DTAC is an outstanding projectile--inherently accurate, easy to tune, and slippery in the wind. While perhaps a bit heavy for the 6BR or even 6BR Improved case, it works perfectly in the 6XC case. This combination--115 grainer in 6XC case--is a proven winner. The new 6mm bullet won both the 2004 NRA High Power Long Range Rifle Championship and across-the-course title. Shooting a Tubb 2000 rifle in the Long Range event, David set a record with the first-ever perfect score of 1450/1450. Is the 6XC for you? Consider these credentials: 1. The 6XC won the NRA High Power Rifle Nat'l Championship the last four years. 2. With the 115gr DTAC, the 6XC is now a viable long-range cartridge with ballistics that rival a 6.5-284 shooting a 142gr SMK at 2950 fps. This means that a Cross-course shooter can now use one rifle and one cartridge for all events.



To order DTAC 115gr bullets or 6XC brass, contact Superior Shooting Systems: (806) 323-9488. Bullets cost $18/100 with a 500-ct minimum. Tubb-headstamp 6XC brass runs $32/100.



Loading the 6XC with 115gr DTAC bullet -- By David Tubb CARTRIDGE PROPERTIES:



Water capacity of the Superior Shooting Systems Inc. (DTAC) 6XC case is just under 50 grains capacity. Case neck length is .305 inches so a 115 gr. DTAC bullet seated .015 inches in front of the neck-shoulder junction will have .290 inches of neck support at the start of use in a newly chambered barrel. This allows one to keep seating the bullet outward as the throat wears and yet have plenty of case support for the bullet over the life of the barrel. I have used less than .170 inches of neck support with good results when feeding out of the magazine. Seating the 115 gr bullet about .015 inches in front of the neck-shoulder junction gives an approximate overall length (OAL) of 2.750 inches, which will allow you to grow your round (for magazine feeding) more than .100 inches when using a Tubb 2000 magazine. NECK PREP: I neck turn all of my long range brass and clean it up to approximately a 60-percent level. I just try to eliminate any overly thick necks or high spots. BALLISTICS: The 115-grain DTAC has approximately 10 points lower BC than a 142gr 6.5mm Sierra. Everybody's BC calculations vary so I believe this is the best way to evaluate it against the 142gr 6.5 Sierra. (Also if you look at the Berger 115gr 6mm keep in mind that Bergers BC's are not conservative at all.) This means that if you shoot the DTAC 115 at 3000 fps verses the Sierra 142 at 2950 fps then the drift at 1000 yards is virtually the same. [Editor's Note: Henry Childs has confirmed the BC figure David is proposing. We suggest you use a .585 BC for the 115gr DTAC.] I use moly-coated bullets exclusively, so the loads listed need to be reduced 1-1/2 grains if an uncoated bullet is substituted. All of my long range loads are seated long and are pushed back into the case upon the closing of the T2K bolt. Likewise, all of my long range loads are full-length resized each and every time (approximately .003 inches shoulder set back). I use the Superior Shooting Systems Custom 6XC die set (see below). I used the .268 bushing in the sizing die with the expander plug (for long range only; I use a smaller bushing for across the course rounds). PRIMERS: I have been using Russian primers exclusively. They use a different sinoxide (close to the European type) compound mix which (in my testing) consistently delivers better extreme spreads over Federal 210's. Be sure they are seated firmly into the case--if not they can be hard to ignite. POWDER: I tried Hodgdon H4831 but could never get the velocity I wanted out of a 27-inch barrel; with this powder velocity without any brass flow (shiny spot) on the ejector plug was around 2930 fps. (4831 might be worth a try if one has a 32-inch barrel). I ended up with H4350 -- the same powder I use with my 107 gr. Sierra bullets in this cartridge. I use the ejector plug brass flow as my pressure indicator -- when I see a shiny mark on the case head I automatically back off the charge 1/2 grain. I have shot the DTAC 115 at over 3100 fps but saw too much pressure. I can shoot this 115 at 3050 fps and have a reloadable/reusable case; however, out of my 7.5 twist barrel it did not shoot as well as when I backed the load down another 1/2 grain to 39.6 gr. of H4350. This gave a velocity (depending on temperature) of anywhere from 2988 to 3020 fps. When I got home from Camp Perry I rechronographed the ammunition I used there and it was going 2990 fps (early morning, cooler temp.); mind you, this was several hundred rounds later in the barrel's life. "I have shot many calibers over the years . . . only the .308 Winchester is as easy to load for as the 6XC. When I started playing with the 115gr DTACs at 1000 yards I could immediately tell that when one gets the unexplained shot (that occasionally happens) the 6XC is much more forgiving in the result -- which means instead of wide 10 or even a 9-ring shot, the 6XC's bad shot is a mid-ring 10." -- David Tubb

Field Testing at 1000 YardsI shot four different 6XC barrels (three were 7.5 twists and one 8 twist) this past season and they all shot the same. I did quite a bit of testing at 1000 yards -- 20-shot groups prone -- and the best group (27-inch barrel, 7.5 twist) was 5.5 inches elevation for 20 shots (group was about 15 inches wide -- wind was blowing but somewhat steady and the target was marked after each shot). The group shown in the photo was shot with a 29" barrel (7.5 twist) and the conditions were almost calm -- also keep in mind that I can't hold much better than a 3-inch spotter when shooting prone at 1000 yards. I feel that the 6XC cartridge will continue winning for some time to come since it now offers a good long range bullet with a decent BC, lower recoil than a .308 or 6.5x284, and because of the fact that it is a very easy cartridge to load for (i.e. develop and tune very accurate loads). Click here to download the lastest Load Data (and loading advice) for the 6XC as a .PDF file. Neck Tension and Selecting a Sizing BushingTwo neck/shoulder sizing bushings are included with the die set (see below). One is .265 diameter, one is .267 diameter. Depending on the make and lot of brass you're using, there may be different neck wall thicknesses. I choose a bushing that gives me 0.003-plus case neck tension on the bullet. In other words, I measure the sized case neck inside diameter and want that to be 0.003 smaller, or slightly more, than the actual bullet diameter (0.243 inches). Due to differences in wall thickness and brass characteristics, different brands and lots of brass may size "differently" than others. The best way to proceed might be to size a few cases using each bushing and see what the end results are by measuring outside case neck diameters before and after seating a bullet into them. That is the sure way to determine case neck tension, and, therefore, which bushing to choose for routine sizing use. Another way to do it is measure the outside diameter of the case neck of a loaded round and subtract 0.004 from that figure (accounting for spring back in the brass); use the bushing that is closest to that figure, but err on the side of the smaller bushing. My experience has been that the only real danger is having too little neck tension to hold the bullet (less than 0.002" difference). 6XC Brass -- Ready to Shoot with a .308-style RimNew 6XC brass, ready to shoot out of the box, is available from Superior Shooting Systems. You don't have to worry about forming the cases out of .22-250 brass any more. The rim thickness is that of a 308 case (.049) so you won't need a different shellholder (.22-250 is .044" rim thickness). The web specified for this case is similar to the .338 Lapua. This gives a much stronger back end as well as more uniform powder ignition. A Neco gauge on the web showed right at .002" runout on the body wall. The brass is much more affordable than Lapua or Norma brass. Prices for the Third Batch of 6XC brass are now $32 per hundred and $30 per thousand. Order from Superior Shooting Systems, (806) 323-9488. Incidentally, the Third Batch of brass is due in approximately 2 weeks (we will have hopefully filled all the backorders by the end of Nov.) The Third Batch of 6XC brass is approximately six points harder than Lapua (on the Knupe scale), which means that there will not be any stickiness at the top of the bolt lift.



6mmXC Cartridge Specifications

 

The loading data below was attained using the following combination of components:Remington .22-.250 parent caseFederal 201M [match] primerI have had good success with all propellants listed in this loading table. My winning load for 2002 was with Hodgdon 4350; in 2001 I won with Viht. N150.New cases may require a few firings to attain a length beyond 1.900. This is nothing to be concerned with as it is perfectly fine if the cases are a little bit short.



WARNING



xxx[ALL loads listed are with moly-coated bullets! Using these loads withxxxnon-coated bullets will result in higher pressures.]

   

xxx[PLEASE NOTE also that ALL loads listed are with a new Gary Schneiderxxx polygon barrel. Conventionally-rifled barrels will require more propellant toxxx attain listed velocities..]

 

Load Suggestions



Fire-Forming Loads      



[with Sierra 107gr. moly-coated MatchKing]



xxxVihtaVouri N150: 34.0 gr. [approx. 2900 fps]



xxx Hodgdon VARGET: 34.0 gr. [approx. 2900 fps]



xxx Hodgdon 4350: 38.0 gr. [approx. 3000 fps]



xxx VihtaVouri N160: 38.0 gr. [approx. 3000 fps]





200 Yard Event Loads

 

[with Sierra 107gr. moly-coated MatchKing]



xxx VihtaVouri N150: 33.0 gr. [approx. 2850 fps]



xxx Hodgdon VARGET: 33.0 gr. [approx. 2850 fps]



xxx Hodgdon 4350: 37.0 gr. [approx. 2950 fps]



xxx VihtaVouri N160: 37.0 gr. [approx. 2950 fps]



300 Yard Rapid Fire Loads xxxx



[with Sierra 107gr. moly-coated MatchKing]



VihtaVouri N150: 33.0 gr. [approx. 2850 fps]



xxx Hodgdon VARGET: 33.0 gr. [approx. 2850 fps]



xxx Hodgdon 4350: 37.0 gr. [approx. 2950 fps]



xxx VihtaVouri N160: 37.0 gr. [approx. 2950 fps]



600 or 1000 Yard Event Loads



[with Sierra 107gr. moly-coated MatchKing]



VihtaVouri N150: 35.0 gr. [approx. 2950 fps]



Hodgdon VARGET: 35.0 gr. [approx. 2950 fps]



Hodgdon 4350: 39.0 gr. [approx. 3020 fps]



VihtaVouri N160: 39.0 gr. [approx. 3020 fps]



Note --xxxx   

After your 6mmXC cases are fire-formed using one of the fire-forming loads listed below, I suggest starting at that listed fire-forming load when working up your 600 or 1000 yard load. Chronograph and watch for pressure signs. It is also suggested to schedule velocity checks every few hundred rounds and adjust propellant charges as indicated to maintain "new barrel" velocities.

Short Line Loads (reduced bullet weight)xxxx   

I use 107gr. bullets across the course. Due to the inherently light recoil of this round and bullet weight combination, I see no need of reducing bullet weight, and it never hurts to shoot a bullet at all yard lines that offers superior wind-bucking capability. However, if someone wants to experiment with lighter bullets for 200 yard events, I would simplify matters by shooting the 600 yard load with the lighter bullet. A very light bullet, like a 70gr., might need to have the charge increased a grain or more, but the idea is to reduce recoil and also ensure flawless bolt operation, so I don't think a maximum velocity load is wise in this instance.

[HJu]

SM-kisaajia lohduttanee tieto että ResULin nykyiset kisasäännöt määrää TA SM-kisoihin minimikaliperiksi 6.5mm :-)



Tuo 6mm XC on kyllä niin villikissa kuin olla ja voi. Lisätietoja http://www.zediker.com">http://www.zediker.com -saitilta.

[kampsa]

mikä tuossa patruunassa oli nyt sitten niin ihmeellistä? helppo kertoman mukaan ladata tarkaksi muttei nyt sen ihmeellisempää,,

lähdöt 930-911m/s nurkissa,vanhasta ppc patruunasta irtoaa samat? ja ehkä ylikin,,



hyvä käyntinen jutun mukaan,,on tosin ampujasta myös paljon kiinni?

tämän foorumin ampujista itseni mukaan lukien kukaan taitaisi ampua jatkuvasti 1000 jaardiin 9-10 rinkiin taulussa??



meikäläisen näkökulmasta ei varmasti olisi sen helpompi ampua,kuin nykyinenkään ase,,mahdollisesti jopa vaikeampi olisi osua,,



tulee mieleen vähän väkisinkin norma br 6mm,jolla ruotsin armeijan testeissä olivat ampuneet aika hurjia tuloksia,,

800m:in kasat 10cm kokoluokkaa norman tehdas patruunalla.



tämä nyt lähinnä pohdiskelua aiheesta johon suhtaudun hiukan varauksella.

mutta hyvä kuitenkin et kehitys kulkee koko ajan eteenpäin,,

[HJu]

: mikä tuossa patruunassa oli nyt sitten niin ihmeellistä?



Ei mikään yksi asia. Usean asian kombinaatio sen sijaan tekee siitä ainakin Tubbin mielestä hyvän.



- Ruutia palaa vähän (vähän rekyyliä, piiput kestää tarkkoina pitkään)

- Ruutipanoksen palaminen on hyvin tasaista ts. lähtönopeudet ei paljon heittele

- Pitkä 107 greinin luoti mahdollistaa latauspituuden kasvattamisen ylimenokartion syöpyessä paljon paremmin/pidempään kuin useimmissa 6.5mm patruunoissa jotka mahtuva 308-lippaaseen (TA-käytössä täysin merkityksetön asia, kisakäytössä aika merkittävä asia jos säästyy kaudessa yhdeltä piipunvaihdolta)

- Patruuna on sopivan lyhyt ja sopusuhtainen että se syöttyy .308pituiseen aseeseen lippaasta ilman ongelmia. Tällä on merkitystä USAn kisoissa joissa ammutaan 200 ja 300 yardiin pika-ammunnat. Yksi lipashäiriö vie koko kisan automaattisesti penkin alle. Tästä syystä 6mm BR ei ole kovin suosittu koska monessa aseessa se ei syöty lippaasta ollenkaan. TA-aseissa ei välttämättä paljon merkitse.



: helppo kertoman mukaan ladata tarkaksi muttei nyt sen ihmeellisempää,,

lähdöt 930-911m/s nurkissa,vanhasta ppc patruunasta irtoaa samat? ja ehkä ylikin,,



Ammupa nyt kokeeksi 6mm PPC:llä 1000 yardiin kasoja. Eli noilla raskaammilla luodeilla PPC:llä tulee ongelmia ruutitilavuuden kanssa ja piipun rihlannousukin pitää muistaa valita kireäksi ts. vakio-PPC:llä (esim. Sako) ei tule mitään. Lisäksi lipassyöttö (ja hylsynpoisto) lähes tasapaksulla hylsyllä maksimilatauksilla ei ole kirkossa kuulutettu.



: hyvä käyntinen jutun mukaan,,on tosin ampujasta myös paljon kiinni?



Vakiopiippuajat helpottaa kaikkia ampujia.



: tämän foorumin ampujista itseni mukaan lukien kukaan taitaisi ampua jatkuvasti 1000 jaardiin 9-10 rinkiin taulussa??



En minä ainakaan.



: meikäläisen näkökulmasta ei varmasti olisi sen helpompi ampua,kuin nykyinenkään ase,,mahdollisesti jopa vaikeampi olisi osua,,



Vakiopiippuaika ja pieni rekyyli ei pitäisi ainakaan haitata.



: tulee mieleen vähän väkisinkin norma br 6mm,jolla ruotsin armeijan testeissä olivat ampuneet aika hurjia tuloksia,,

800m:in kasat 10cm kokoluokkaa norman tehdas patruunalla.



6mm BR on ballistisesti hyvä ja Jalonen on saanut sen syöttymään lippaastakin. Moni muu, kuten Remington tai Blaser ei ole tässä onnistunut. Niissä kisoissa joita Tubb ampuu ammutaan puolet laukauksista pikatulena lippaasta jolloin ei-lipasystävälliset patruunat ei ole suosittuja koska kisaa on ikävä hävitä lipashäiriön vuoksi.



TA-käyttöön 6mm BR on muuten hyvä mutta TA SM-kisoihin sillä ei ole asiaa. 6.5mm BR sen sijaan kelpaisi sinnekin.



Minun mielestä 6mm XC on optimoitu lähinnä 200.300 ja 600 yardin kivääriammuntoihin. Ei se ole mielestän kovin järkevä patruuna Suomessa jossa hylsyt pitäisi muokata ja TA-käyttöön tuo on vähän lussu muutenkin.



Eli optimaali patruuna USAn sääntäjen mukaisiin kiväärikisoihin, ei välttämättä paljon muuhun.

[MJ]

Moi,



Hyviä kommentteja HJu!



Joo, tuo 6mmXC taitaa olla lähinnä Jenkkien NRA-kisoja varten suunniteltu. Olisi tietysti mielenkiintoista kuulla kasa-ampujien kommentteja ko. patruunasta versus 6mm BR tai PPC.

: tämän foorumin ampujista itseni mukaan lukien kukaan taitaisi ampua jatkuvasti 1000 jaardiin 9-10 rinkiin taulussa??



En minä ainakaan.

En minä myöskään.



Veikkaanpa niin, ettei David Tubbin veroista tai edes likikään hänen veroista kivääriampujaa löydy Suomesta.



D. Tubb on kyllä aika ilmiö ampujaksi.



Carpe Diem,



MJ