Keyholing??
 

The other day, I loaded some Meister bullets 165 grain cast bullets in my .30-06. I loaded them to a velocity of 1800 fps. They did not have a gas check. When I examined the target, I noticed keyholing. Does anybody know what would cause this. I think it may be related to the bullet, but not sure. Here is a pic of the target.

RE: Keyholing??
 

By chance, is your rifle an old military model? If not, is is quite old? The problem probably lies in the rifling. The rate of twist will not stabalize that bullet. If your load data will allow, try to spice up the velocity a bit. If still no go, go back to a different bullet that will stabilize. Hope this helps.

RE: Keyholing??
 

The rifle is a Sears Model 53 that my Grandpa gave me. He bought it new sometime in the late 60's. I think the rifling is 1 in 10", so it should stabilize just about any bullet I feed it.

RE: Keyholing??
 

charlie brown,
What powder?
How many grains?
Why no gas check?
How is the muzzle crown?, any burrs?
How many shots are in that target?

RE: Keyholing??
 

30 grains of AA 2460, the bullets didn't come with a gas check as they weren't designed to, there are no burrs on the muzzle crown, 3 shots in the target.

RE: Keyholing??
 

Yep looks like they are wobbling or maybe even tumling. with that twist 1800fps isn't fast enough, i would guess. If your cast is hard enough I'd try boosting them up to around 2100fps. If it works and dosent lead up you've got yer fix. Oh yeah you might need to check your seating. Make sure they aren't seating a little crooked.

RE: Keyholing??
 

I would try slowing it down to 1600-1700 fps if you don't have gas checked bullets. having the base of the bullet degrade in the bore from gas cutting will certainly cause keyholing if not just poor accuracy.

Did you slug the bore and compare it to the bullet diameter? I would bet that the Meister bullets are undersized and you are getting alot of blowby.
I've used meister bullets for 9mm before and they were sized to exactly .355" when I needed a bullet of at least .356"- bullets went all over the place[:@]


When seating the bullets, seat them so that they seat firmly into the rifling, if possible, don't let the base of the bullet extend below the case neck- which shouldn't be too much of a problem if you are shooting a 30-06, but might be a problem with a .308.