Suddenly keyholes!

[mpmarty]

My Witness Elite Match has always been a dream to shoot in IPSC matches and just for fun also. I use a 170 gr LEE tumble lube boolit and 5.5 grains of Red Dot. This has worked very well for me for a couple of years. Now, suddenly I'm getting profiles instead of round holes. Accuracy is actually not bad out to 25 yards but the keyholing is driving me nuts. No leading problems just sideways boolits on target. Any ideas where to look first?

[mooman76]

Just winging it but is your lead a different hardness than before and have you looked at your crown?

[runfiverun]

unstabilized somehow.
look at your velocity,you my have a slow lot of powder you might need to bump it up some.

[SierraWhiskeyMC]

Have you changed your boolit alloy? Do your boolits weigh about the same as they did before?

If you're using a lighter alloy than before, that could explain it. Lower MV might also explain it.

[Bret4207]

Yup, SOMETHING changed. You need to figure out what. Powder, primer, alloy, lube, crown, a spring weakening, brass, maybe throat wear or other barrel wear. It's even possible your mould has changed, worn maybe. Different sizer or die?

There are a lot of things that it could be, check one at a time.

[cast-n-blast]

Check your barrel, it may be severely leaded.

[fredj338]

Are you siazing bullets or shooting as cast? Is it every round or just some? I am betting undersized bullets if shooting as cast? If all the rounds are keyholing, my next though is the barrel has gotten very sick.

[mpmarty]

Zero leading in barrel. Boolits are LLA lubed, sized to 401 and lubed again. Same batch of pure ww air cooled. Barrel seems OK and my two other 10mm Tanfoglios do about the same keyhole trick. I'll try up loading to higher velocity as I'm well within specs to go faster.

[jdgabbard]

Well, you narrowed it down to something in the load then. I'm gonna say either the boolit, or maybe your size die is leaded and is causing smaller then wanted boolits.

[mpmarty]

Family reunion all day tomorrow. I'll put a mike to them on Sunday. I'll also take a close look at the push through sizer from Lee. It should not lead as all boolits are lubed prior to sizing but who knows?

[hyoder]

If you are taper crimping, and should be, back off a little on the crimp die. Too much crimp will swage the boolit down.