Need Help: .308 FTF

[Madusa]

Your guns dirty (firing pin blockage) or your primers are bad. Just a Guess.

[james_bond_007]

Your guns dirty (firing pin blockage) or your primers are bad. Just a Guess.

Another vote for bad primers...

I will check and clean the firing pin. Good suggestion!!!

After cleaning, I will chamber one of the rounds that had a FTF and see if things behave better.

Note: 100 rounds of commercial ammo has had NO FTFs.

[spqrzilla]

I would check and compare to see if the primers were really struck with a full firing pin strike or if they were lightly dimpled. If the latter, I'd be suspicious of the rounds being a bit too long and the gun not going fully into battery.

If the cartridges fired upon a second time, then the primers were not fully seated.

[james_bond_007]

I would check and compare to see if the primers were really struck with a full firing pin strike or if they were lightly dimpled. If the latter, I'd be suspicious of the rounds being a bit too long and the gun not going fully into battery.

If the cartridges fired upon a second time, then the primers were not fully seated.

I DID re-chambered them a total of 2-3 times and tried to fire them. Still did not fire.

I'll check the "dimple".

The "not into full battery" suggestions is good.
They COULD be too long (but so far most posts in my other thread "Need Help: OAL varies" don't think so).

But...If I did not full re-size them properly, they COULD possibly be a bit too "fat" to fully seat in the chamber (especially if they originally were fired in a machine gun; I'm told that the machine gun chambers are made a bit "loose" to facilitate easier chambering/extraction at high speeds). I'm told that military brass has a "thicker" case wall and can "spring back" a bit after a full case resize. I can check the case diameter against the SAMMI spec or just try to insert one in the chamber and see if it easily goes all the way in.

Thanks again, for the suggestion.

[spqrzilla]

Military brass is not going to "spring back" more than commercial brass if correctly resized. If the shoulder was not pushed back far enough, or the bullet seated out so far that it touches the lands before the bolt is fully in battery, you could see a situation where the firing pin flys forward on trigger pull but is prevented (by design) from giving a full strike to the primer.

Unless contaminated, "bad primers" are the least likely cause.

[XC700116]

First make sure your FL resizing is being done correctly and fully, the first thought that came to my mind is that it's not getting fully into battery as spqrzilla mentioned. If you are right on the fine line of some going in and some not going into battery, this is also potentially creating a tight to zero headspace in your gun and greatly increasing your pressures. That would be the case if you aren't pushing the shoulder back far enough. Take your FTF rounds and start measuring them very carefully and I'd bet you'll find your problem.

as to the OAL moving around while crimping at the ogive, get a good brass trimmer and trim to the correct length and seating at the Ogive should give you SAMI spec ammo and should eliminate all the issues you are seeing.

It's the ONLY way I would ever load ammo for a semi-auto. If you are putting out ammo that is at SAMI spec all the way around you aren't going to have problems like this.

I also agree that the chances of "bad primers" is slim to none.

[jmg8550]

As an M1A shooter, I have had a "squib" load before. You won't hear anything, even when the primer goes off. It just sounds like a dud. I have never had that many bad primers... ever, and have loaded at least 5000 rounds. Pull the rest of your reloads and make sure they have powder. Then, if you want to, chamber a primed empty case and fire it. It'll just sound like a firecracker.

Also. I believe 46 grains of either 4895 is a little hot for the M1A. I load 42 grains and it is accurate. A 155 grain bullet according to Hornady, has a max charge of 42.9 (h4895) and 43.4 (IMR4895).

[james_bond_007]

Thanks to all who took time to read and comment on my issue.

The cause of this issue was that the case was getting compressed just below the shoulder in the seat & crimp process to the point where it buckled slightly. The cartridge did not go fully into battery as it seated too "soon" in the chamber, due to the slight "buckling".

I found this out by, at the advise of some of the postings, getting the SAAMI spec, a pair of calipers, and began measuring everything I could, using a commercial round as another reference.

Seems that when I attempted to seat AND crimp, in one step, the crimp was taking hold BEFORE the bullet was fully seated. Thus when continuing to try ans set the bullet, it sort of "squished" the edge where the shoulder met the case side and caused a slight bulge. I found this out by running an uncharged/unprimed bullet/case through the die and trying to seat it just a wee bit deeper. The "bulge" was exaggerated, and demonstrated my issue .

To test this theory, I did the bullet seating and crimping in two separate steps.
Measurements confirmed all was within spec.
Range testing affirmed that things were better.
No FTFs, FTEs, or other.

Also, the load that seemed to group best was 42.5 grains of H4895 (I was comparing load sizes, not brands of powder. I only used H4895 for this test). I will stay in that range, for safety and accuracy.

Thanks again.....

[Zombie Steve]

Glad you got it figgered out. I was on the right track, but looking at the wrong cause.

[james_bond_007]

This issue is back --- FTF and FTE.
I THOUGHT I had it figured out, but perhaps not ALL the issues.

Someone suggested that I may need to use a SMALL BASE FL re-sizer for the military LC brass (at least for the first sizing).

How can I determine if this will help?

Would a Wilson CASE GAUGE help ?

Do I need more sophisticated tools to measure anything ?

...getting frustrating

Anyone up my way (I-25/120th Westminster) reload for the M1A and willing to take a 2nd look?

I have various flavors of brass (sized, fired by me, etc.) for some clues...