Hornady .308 hylsyn paino?

[jtlassila99]

Tonite I shot my first loads with the SMK169.  I was expecting 2760fps but got 2795.  This was 12 shots.

The SMK169 seems to produce more velocity than the SMK168.  Anyone else seen this?

This was unsorted Hornady 308W brass, WLR-M, SMK169, 45.0gns Varget, COAL 2.92.  This was a sligthly compressed powder load, perhaps 105%.

The WLR-M primers are flattened but they are known to do that before max loads.  No stiff bolt.

I may switch to a harder primer though.

I plan on shooting this at the US Camp Perry National Matches in August at 1000yds.






The 45gn, 2800fsp HRN cases are the two on the left.

[jtlassila99]

What kind of velocity do you guys get with the .308 SMK169?

With my 45gns varget loads I had a few stiff bolt lifts with the faster shots.  The Win LR Magnum primers are pretty flattened and formed to the generous bevel of the HRN primer hole, it seems.

I got some CCI-250 primers, which are supposed to hold up better at high pressure.

I'm thinking of lowering powder charge 0.5gns for about 2760fps or so.   The match will all come down to reading, calling the wind, which I'm not good at it.  But velocity does help.

WLR-M primers in HRN case at 2800fps, on the left:


This is how the primers look like removed:


This is how the CCI-250 primers look like at the same load, 2800fps:

[tönäri]

Tonite I shot my first loads with the SMK169.  I was expecting 2760fps but got 2795.  This was 12 shots.

The SMK169 seems to produce more velocity than the SMK168.  Anyone else seen this?

This was unsorted Hornady 308W brass, WLR-M, SMK169, 45.0gns Varget, COAL 2.92.  This was a sligthly compressed powder load, perhaps 105%.

I haven't loaded SMK 169gr and i'm just playing with physics, my old semi auto 308 valmet isn't meant to push max loads 

According to googled info: SMK 169gr = 1.308" and SMK 168gr = 1.200"

Your load lengths 2.92" for 1.308" bullet and 2.875" for 1.200" bullet. So 0.045" increase of COAL meanwhile bullet increased 0.108". So it will reduce powder capacity, being smaller burn space for same amount of powder would cause higher pressure, which means more velocity. So by having longer bullet you actually gain velocity, on top of that you increased load by 0.4 grains which gives even more velocity, hence the pressure increase and more than expected velocity increase Also the 1grain bullet weight increase, but it's by far the smallest factor here 

GRT says for your load factors that pressure increase is about 4500psi and 50fps more and atleast velocity seems to be fairly close to reality. Velocity going 2731-> 2795fps

[jtlassila99]

I haven't loaded SMK 169gr and i'm just playing with physics, my old semi auto 308 valmet isn't meant to push max loads 

According to googled info: SMK 169gr = 1.308" and SMK 168gr = 1.200"

Your load lengths 2.92" for 1.308" bullet and 2.875" for 1.200" bullet. So 0.045" increase of COAL meanwhile bullet increased 0.108". So it will reduce powder capacity, being smaller burn space for same amount of powder would cause higher pressure, which means more velocity. So by having longer bullet you actually gain velocity, on top of that you increased load by 0.4 grains which gives even more velocity, hence the pressure increase and more than expected velocity increase Also the 1grain bullet weight increase, but it's by far the smallest factor here 

GRT says for your load factors that pressure increase is about 4500psi and 50fps more and atleast velocity seems to be fairly close to reality. Velocity going 2731-> 2795fps

Mika on se GRT?

After extensive consultation with Google AI, I switched back to the GGG brass and dumped the magnum WLR-M primer in favor of CCI-200.  I was concerned about the apparent softness of the HRN brass and the severe flattening of the Win primer. 

Google AI is getting pretty amazing, IMO.

This was 12 shots:  GGG, SMK169, CCI-200, 45.6gns of Varget.  I like the low SD!

[MTä]

Open source reloading tool, which is quite accurate and have quite responsive community in discord.

Gordons reloading tool