Need Help: .308 FTF

[SA Friday]

After reading the thread, I believe your issue is the brass. More than likely, it was shot in a gun with a fairly liberal chamber and has been bulged out toward the back. I agree with Delfuego in that you need to isolate the issue by changing one thing at a time until you isolate the problem. You need to reload and shoot some basic commercial brass and see it the fail to fire problem goes away. The SB dies might help, but you don't know yet if it's needed or not. isolating the problem to the once fired LC brass would be the first step, not trying the SB dies. If you try commercial brass and it works, then you can look at the dimensions around the webbing of the commercial brass and compare it to the dimensions of an unsized LC brass and see it it's been bulged out. Hoser's suggestion with the marker will also show if the webbing area is bulged far out enough to not chamber even after resizing. Then, the SB dies may take care of the problem. Another choice is if the commercial brass works, but the LC brass is just too blown out, stop using the LC brass. Some military once fired just gets tore up depending on the gun it was shot out of. It may not be reusable.

Last thing I would check it to see if you actually NEED to crimp the cartridges. I have very little M1A experience, but I would work off the hypothesis that crimp isn't needed until I tested it and saw enough set-back for me to start crimping the rounds. This is pretty easy to test. Once you have found some brass that will fully chamber, make a round that is fully resized and the bullet seated to about 2.80", no primer or powder. Then load it in the gun from the mag like you normally would. Remove the round and measure the OAL and see if the bullet was set back into the case. Anything over 0.1" is probably too much and a very very small amount of crimp will stop the movement.

[james_bond_007]

I've mentioned the WILSON case gauge several times, but have gotten few, if any, comments on it.

I've read other posts that seem to favor it, and some that say it is not very helpful, but am getting the feeling not many on this forum have one or use one, due to the lack of comments.

The concept makes sense to me. It is a portable
chamber with min and max SAAMI specs machined into it.
By "chambering" my brass in it, it seems like I should AT LEAST be able to tell if my brass is meeting SAAMI specs.
To me, if the brass meets SAAMI, then it tells me I'm doing the best I can with the dies that I have AND that my reloads are "in spec".

It DOES help isolate the problem a bit and might goes as far as indicating that my NEWBIE reloading/sizing techniques are OK.

Am I off base here ?

[james_bond_007]

... You need to reload and shoot some basic commercial brass and see it the fail to fire problem goes away.

Already working on this test. Glad you confirmed it

The SB dies might help, but you don't know yet if it's needed or not.

Yes, that what I was getting at in post #36

isolating the problem to the once fired LC brass would be the first step, not trying the SB dies. If you try commercial brass and it works, then you can look at the dimensions around the webbing of the commercial brass and compare it to the dimensions of an unsized LC brass and see it it's been bulged out. Hoser's suggestion with the marker will also show if the webbing area is bulged far out enough to not chamber even after resizing.

Been measuring lots of stuff (caliper and micrometer): various commercial new, NATO new, my brass sized/fired. Seems to be in SAAMI spec. I had some other reloaders measure it as well. I also like Hoser's suggestion and am going to try it. I'm thinking of building up some uncharged/unprimed cartridges, marking them (as per Hoser's suggestion) loading a mag with them, and trying to cycle them by hand. I'll examine the markings.

Some military once fired just gets tore up depending on the gun it was shot out of. It may not be reusable.

I did not know that there was some once fired brass that could be brought back into spec and would still be unusable. This is new info. Thanks.

Last thing I would check it to see if you actually NEED to crimp the cartridges. I have very little M1A experience, but I would work off the hypothesis that crimp isn't needed until I tested it and saw enough set-back for me to start crimping the rounds. This is pretty easy to test. Once you have found some brass that will fully chamber, make a round that is fully resized and the bullet seated to about 2.80", no primer or powder. Then load it in the gun from the mag like you normally would. Remove the round and measure the OAL and see if the bullet was set back into the case. Anything over 0.1" is probably too much and a very very small amount of crimp will stop the movement.

I'll look info this. Lately I've been putting NO crimp on them and just allowing neck tension to hang on to them. I like your test to determine if the neck tension is sufficient (i.e. does the bullet move to to being slammed home in the chamber?) and will try it with my dummy loads mentioned above.

Thanks for the suggestions, guys. I've got some testing to do....

[jerrymrc]

One more thought that I did not see brought up that you might want to check.

I know some have had issues with once fired brass that was banana shaped. Did not look like it and sized just fine but would not chamber.

Testing showed that even after sizing there was a "bow" in it. Might not hurt to lay some on a piece of glass and roll them.

[SA Friday]

One more thought that I did not see brought up that you might want to check.

I know some have had issues with once fired brass that was banana shaped. Did not look like it and sized just fine but would not chamber.

Testing showed that even after sizing there was a "bow" in it. Might not hurt to lay some on a piece of glass and roll them.

Ya, this is what I was getting at about some military brass not being reusable. The belt feds can get pretty brutal on the brass, and there are times when the angle of the case head in comparison to the case wall is just too out of specs to reuse the cartridge.

[jerrymrc]

Ya, this is what I was getting at about some military brass not being reusable. The belt feds can get pretty brutal on the brass, and there are times when the angle of the case head in comparison to the case wall is just too out of specs to reuse the cartridge.

I thought as much.

[Hoser]

Earlier this year I shot a big 3-gun match in Phoenix with the gang from Dillon Aero and Dillon Precision. That would be the Dillon as in Mini-Gun and reloaders.

One of the guys was shooting an HK-91 and another was shooting a M1A. Both were using brass that had gone through a mini-gun.

I bet about 2 in 10 pcs (maybe more) of brass I picked up was about ready to have the case head separate due to the violent extraction of the mini-gun.

When I reload ammo for a semi, the last die the ammo hits is a body die. This is to be 100% sure the base got completely resized and the shoulder got bumped back a thou or two.