question on handloading military brass

tkofoid · October 21, 2008, 04:48 PM

I handload the .308 and use military brass. I back off 1 - 1 1/2 grains of powder due to the so-called smaller capacity of the case.
My question is this: Because the capacity is smaller and I drop back my load do I get the higher velocities than my manual shows? To me pressure equals velocity so even tho I backoff on powder I still create the higher pressure thus more velocity. Any input would be great. I have asked this question many times to fellow shooters, but no one has a solid answer. Maybe one of you out there has cronographed the differences?

velocette · October 21, 2008, 05:02 PM

Most military brass is heavier / thicker than most commercial brass.
That said, there are some commercial .308 brass that is quite thick and heavy. Specifically Federal. (Fed also appears to be the softest brass)
My suggestion is to weigh about 20 pieces of each brand / lot of brass you have, then average the weights. You will soon see which ones are heavier / thicker, demanding reduced loads.
In my experience, among commercial brass, Fed is the heaviest, RP next, Win, then Hornady the lightest. YMMV. I have a couple of lots of military brass that is lighter than the Fed average. So you should weigh and verify yourself.
Incidentally, try 41 gr of IMR 4895, Sierra 168 HPBT match bullet, fed brass and Fed match primer 2.8" loa. Shoots about 3/4" groups out of my EBR all day long.

Roger

amamnn · October 21, 2008, 06:32 PM

The best method is to check the internal capacity by filling fired and cleaned, but not deprimed, cases with water and compare. The weight can be the same but the distribution of the brass will determine the actual capacity.

I found that some retired military 30-06 and .556x45 cases I used were actually a bit bigger inside than some Winchester cases I had at the time. I was using the old reduce the load because it's ex military brass rule too, then. Someone told me to do the water thing and I upped the load and got some better groups.

As noted above, the capacities can vary considerably, so it's best to check them all when you don't know if they're all from the same lot. I'm told that if you get hold of some cases that were made for machine guns you may find their capacity to be much smaller than commercial brass.

October 21, 2008, 04:48 PM	#1
tkofoid Senior Member Join Date: October 10, 2008 Location: N. D. Posts: 149	question on handloading military brass I handload the .308 and use military brass. I back off 1 - 1 1/2 grains of powder due to the so-called smaller capacity of the case. My question is this: Because the capacity is smaller and I drop back my load do I get the higher velocities than my manual shows? To me pressure equals velocity so even tho I backoff on powder I still create the higher pressure thus more velocity. Any input would be great. I have asked this question many times to fellow shooters, but no one has a solid answer. Maybe one of you out there has cronographed the differences?

October 21, 2008, 05:02 PM	#2
velocette Senior Member Join Date: May 25, 2007 Location: South Florida Posts: 924	Most military brass is heavier / thicker than most commercial brass. That said, there are some commercial .308 brass that is quite thick and heavy. Specifically Federal. (Fed also appears to be the softest brass) My suggestion is to weigh about 20 pieces of each brand / lot of brass you have, then average the weights. You will soon see which ones are heavier / thicker, demanding reduced loads. In my experience, among commercial brass, Fed is the heaviest, RP next, Win, then Hornady the lightest. YMMV. I have a couple of lots of military brass that is lighter than the Fed average. So you should weigh and verify yourself. Incidentally, try 41 gr of IMR 4895, Sierra 168 HPBT match bullet, fed brass and Fed match primer 2.8" loa. Shoots about 3/4" groups out of my EBR all day long. Roger __________________ Trigger control + Breath control + Sight alignment = Gun Control. http://www.hrpclub.info/ NRA Smallbore Prone Master, High Power Master

October 21, 2008, 06:32 PM	#3
amamnn Senior Member Join Date: May 13, 2006 Location: WA, the left armpit of the USA Posts: 1,323	The best method is to check the internal capacity by filling fired and cleaned, but not deprimed, cases with water and compare. The weight can be the same but the distribution of the brass will determine the actual capacity. I found that some retired military 30-06 and .556x45 cases I used were actually a bit bigger inside than some Winchester cases I had at the time. I was using the old reduce the load because it's ex military brass rule too, then. Someone told me to do the water thing and I upped the load and got some better groups. As noted above, the capacities can vary considerably, so it's best to check them all when you don't know if they're all from the same lot. I'm told that if you get hold of some cases that were made for machine guns you may find their capacity to be much smaller than commercial brass. __________________ "If the enemy is in range, so are you." - Infantry Journal