[101AirborneE8]

I have an old "Blue Sky" M-1 Garand.

Upon taking it to the range, it is showing flattenned and bulged primers that I believe may be due to backpressure from wear & excessive headspace.

Can M-1 headspace be easily adjusted without a complete rebarrel job? If so, what would be the cost difference, and does anyone have a gunsmith recommendations for such a job?

I've checked Fulton Armory's web page. I'm sure that they do fine quality work, but a new barrel job would cost about what I paid for the rifle.

[10X]

The first thing to do is confirm there is a head space problem.
Take the rifle to a gunsmith you trust and have them check it with their gauges.

Is the rifle functioning OK? Fires, the case ejects and the next round feeds OK?

Head space problems I have seen find the base of the case tearing away partially or fully from the rest of the case.

Flat primers sound like excess pressure and bulged primers sound like too little pressure.

[rcmodel]

Sounds like a worn out firing pin, or worn out FP hole in the bolt.
That's a pretty common well-used M-1 problem.

Excess headspace has nothing at all to do with the primer appearance.
In that case, the brass would just stretch until it fit the available headspace, and sooner or later break or separate.

It wouldn't just stay forward in the chamber and let the primer back out.

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

[Jim K]

What ammunition are you using?

Jim

[101AirborneE8]

This was a while ago, but I believe that the ammunition was 175 grain DCM boat-tail fmj bullets loaded with IMR3031, and it was around the middle of the charts insofar as powder volume.

Function was fine. But I always check my primers, and these were appearing to flow into the firing pin hole.

[MutinousDoug]

Armory repair for excessive headspace was to select a bolt that would correct the problem. May or may not be less expensive than a new barrel (assuming that is your problem).

[Onmilo]

You might want to consider using another powder with the heavy bullets.
I like Hodgdon BL-C2 and a lot of other shooters like H4895 or IMR 4895.

Having a gunsmith check the headspace wouldn't hurt but I don't think that was the problem.
The burning rate of IMR 3031 makes it not so suitable for loading in the M1 Garand.HTH

[asknight]

Onmilo is right. 3031 is a bit on the fast side for a Garand, especially so with heavy bullets. 4064 (slower) to 4895 (faster) are the old standbys for a safe and accurate Garand load.

[10X]

I have to agree with the above posters 3031 with 175 grain is not the ideal combination. Use 4895 or 4064.

This isn't a head space problem.

[101AirborneE8]

Thanks.

I had tended to stay with slightly faster powders, because of stories of op-rods being bent because of higher port pressures from slower powders.

If I recall correctly, the Army changed their formula for 30-06 loads, because the earlier ammunition designed for Springfields burned too slowly, and the op-rod problems started occurring.

Maybe I swung a bit too far in the other direction.

Thanks, again.

[rcmodel]

The Hornady #6 manual has a chapter for the M-1 Garand.

They list 10 powders for 178 grain bullets, 11 powders for 168 grain bullets, and 7 powders for 150 - 155 grain bullets.

And IMR-3031 isn't one of them!

http://i81.photobucket.com/albums/j219/rcmodel/KTOG/1224.gif
rcmodel

[asknight]

Maybe I swung a bit too far in the other direction.

Just a tad. Not extremely dangerous, but far enough in the other direction to exhibit the traits on your brass/primers that you're showing. ;)