This past weekend I took my post-WWII M1 out of the safe for the first time in a year (too many guns, not enough time) to shoot.  I fired 2 clips, one was half loaded with Talon M2 and UMC FMJ, the other was all Talon.

I was shooting at 100 yds, and noticed in each group of four, I had one keyhole each.  Not having this problem before, is this issue caused by ammunition or barrel?  Oh, and my groups are 6 MOA or so (yeah, I know that sucks).

I bought the M1 back in 2000 before I really knew what to look for in a used M1.  I've put approximately 80 rounds through it since then, and never noticed this problem before.

Thanks,

-Zmeja

Unless the bullets are bouncing off the dirt before hitting the target is appears your barrel is shot out.  6" group at 100 yards is another indication.

A hard scrubbing may help.

-- Chuck

Thanks for your help.  I'll be getting a new barrel then (after another cleaning session).

-Zmeja

Before buying another barrel I would have the throat erosion checked (in the chamber).

If T&E is worse than 3-1/2 replace the barrel.Also check muzzle wear with a bullet.

Insert a bullet in the muzzle (from a loaded round) and see if bullet goes all the way in to the case mouth.

If it does then you have a worn barrel.If the 2 above steps check out O.K. then just scrub the barrel good (20-30 strokes) with a new brush.

If the barrel is dark inside it's had corrosive ammo shot thru it and never cleaned properly.

I wouldn't throw away a barrel if the TE was only 3 1/2  that is still a good barrel..... now.. if the muzzle was worn.. yes, maybe..... but I have seen barrels with a TE between 3 and 6 shoot just fine and group quite well....

I agree with HighPowerShooter. The Throat Erosion gage reading is just a guide, not something carved in stone. I had a Douglas barrel that T.E.'d 6 that had shot winning scores in 3 EIC Matches and 2 President's Hundred Matches at Camp Perry (this was in the 400 rounds prior to being throat checked). My son only shot this rifle at Perry when he came home on leave in August. When he checked in at AMU with this rifle for the Summer Team, they said he couldn't shoot it due to the T.E. reading. Instead they issued him one of their NM M-14 Rifles. The first three issued to him were junk(bedding broke, barrel wouldn't hold a tight group, and loose sights). Apparently, the full timers got the better rifles and the "Summer Team" got the leftovers.

I'll check the muzzle tonight.

As for throat erosion gauge, would that be something your average gunsmith would have, or will I either 1) have to buy one myself or 2) send the rifle off to Fulton or someone?

Thanks for y'alls help.  Even if it turns out to be a new barrel, it will still take me a while to save up the cash for replacement.

-Zmeja