Need Help: .308 FTF

[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.

[Hoser]

I can not take the pain anymore.

How about I send you a Redding 308 Small Base Body Die and a Dillon 308 case gauge and you see if that helps.

You can use it on loaded ammo as it only touches the shoulder and base.

If they help, order some for yourself and send mine back. If not, on your way to a gunsmith, drop them in the mail to me.

[james_bond_007]

I can not take the pain anymore.

How about I send you a Redding 308 Small Base Body Die and a Dillon 308 case gauge and you see if that helps.

You can use it on loaded ammo as it only touches the shoulder and base.

If they help, order some for yourself and send mine back. If not, on your way to a gunsmith, drop them in the mail to me.

Hoser:

Thank you for the offer....and sorry about the pain.

I wanted to take some time to do some more research and gets some more opinions from the M14 forum guys.

There were a lot of good suggestions from you and others. I had to sort through them and decide the next course of action for me to take.

I have no objections to going to a gunsmith, but I'm the kind of guy that likes to dig into the details myself, as long as I have someone to which I can ask questions (i.e., you , and the other forum members).

Due to working too much and traveling out of town, I was not able to get out to a range to try any live fire experiments such as trying my reloaded commercial or new brass (per SAFriday).

So I decided to try some things that didn't involve live fire experiments.

I was not able to promptly respond to your posts (I was not ignoring anyone's help...I was just overbooked). Some of the posting delay here was due to 1) waiting for some "test equipment"** I ordered to arrive (nice to see that I came to the same conclusion of what to buy, as what you recommended, for the most part), 2) me to get back in town, and 3) because my email notifications to this thread got accidentally turned off.

** Ordered 1) Wilson case gauge, 2) Hornady Cartridge headspace gauge and 3) Redding SB FL Sizing die (#91355)

[james_bond_007]

Hypothesis 1: Chamber is scratched/burred etc.

Experiment 1: I found a friend at an auto repair place that had a fiber optic inspection scope (and was a "gun guy").

Results 1: We inspected the chamber. We could not find any abnormalities in the chamber, in the form of scratches, debris, dents, dings, machine marks, rings, etc.
As I had just "scrubbed" it with a ratcheting chamber brush, it looked pretty clean.
We did not have a "good" way to measure the chamber for being out of round without taking the barrel off (with the available measuring tools he had), so I have no data on that.

Conclusion: Chamber tooling seems "OK" (but not 100% conclusive on measurements)

[james_bond_007]

Hypothesis 2: Brass is out of spec. Need to find WHAT is out of spec. Check to see if they will "chamber" in a Wilson gauge.

Experiment 2: Measure brass and rounds with the Wilson gauge and see if it will "chamber" (here I used chamber loosely to indicate it will properly fit in the Wilson gauge).
Note: The M14 guys strongly recommended getting the Wilson case gauge and using it on every round I ever build for the M1A.
So I did.
I measured commercial/millitary fired/unfired, resized cases and rounds, respectively.

Results 2: Wilson gauge helped a lot. It showed:

1. Some unfired military resized/reloaded brass/rounds has a "fat" base and would not go in the gauge (about 1/4"-3/16" stuck out). Needed to push the round out (it would not drop out when the gauge was inverted).
2. Some unfired resized military rounds/brass would "almost" go in the gauge, leaving just the rim above the gauge and would "snap" into the gauge with a bit of force. Needed to push the round/case out.
3. Some unfired resized military cases would not go in and could not be "snapped" in place. These cases also appeared a bit "short" when looking at the small end of the gauge. Possibly due to the neck not being set back enough. Needed to push the round out.
4. Commercial rounds gauged slightly under spec. It easily fit in and slipped out when the gauge was inverted, but was a tiny bit below the 2nd "step" (min).

Conclusions:

• BASE OUT OF SPEC - (1) above indicated the base was not being sized down enough. I'll try a small base resizer die.
• RIMS DEFORMED/OUT OF ROUND - (2) and (3) indicated the rim was out of spec/out of round. Not having a dial indicator handy, I checked the rim's roundness by putting it in my caliper jaws, rotating it, and watching my dial's needle identify where the "high" spots were located. I then filed the edge of the rims lightly until they easily dropped into and out of the gauge. They were no longer too "short", so I conclude that in (3) that the rim was preventing the case from "chambering" properly in the gauge and the setback on the neck was not at fault.
• COMMERCIAL UNDER SPEC - not sure why....