Keyhole problems

[pwdrbrn]

Ruger#1, 218 Bee, 14 tw.fact.bbl., rechambered to 222 Rem.. 50 gr. bullets shoot great(32-3300 fps), 40 gr. Nos. & Dogtown do too, BELOW 3400 fps. 3500 and up, they keyhole @ 100 yds.. H4198 powder, Rem 71/2, mixed brass, pretty standard stuff. Any reasons, ideas, answers, help?!?! Thanks, Tom.

 

[rwk]

Whats your barrel twist

 

[Preacher]

Your 14 t shouldn't be a problem with the 50 grain bullets, so something else is strange here.... Instability is usually the problem but don't seem to fit the bill here....

 

[Ackman]

You may just have to accept that those particular bullets need to go slower in that particular gun.

I have the same problem with a real accurate 221. It has a custom 14 twist barrel that shoots 40's very well at 3450. A 33gr VMax doing about 2900-3000 will shoot little groups like the ones that come with a Cooper. But pushed faster, that same 33 will keyhole every time. Something about that bullet in that barrel. So when those 33's get used, they'll be loaded down.

 

[bheadboy]

instability is a function of enough twist to stabilize the bullet based on the oal length of the bullet. velocity has an effect on the combination of bullet and twist, if you find the combination does not work then one of the 3 is a problem, twist, bullet, velocity

your bbl may not be 14 twist as many "factory twist" are not exace, i have seen some off as much as 1" - check the rate as yours may not be what you think

Bob

 

[camac]

This is not a twist rate or stability problem as we traditionally think of it. Velocity is way fast enough, Twist is way fast enough, Bullet length is way short enough. If you have tried several bullet types or brands and they all do this then whatever the reason (e.g. old rust spots, inconsistent twist rate that effects bullet at higher speed etc etc) you may have to accept the lower velocity. My old 222 14 tw wouldn't shoot the 40 gr accurately so always used 50-52 gr range anyway.

 

[tenring]

Not sure this will help - but with a Ruger #1, you should be able to load those 50 grainers out a little longer. I would seat the bullets to just kiss the lands and see what happens. This may stabilize them enough to overcome the keyholing. Just my .02 cts.

 

[Old Navy]

Spinning them too fast will do the same as too slow. Sierra makes some .223 bullets for single shot pistols. They worked fine in my .223 contender but not in my .22-250 Lone Eagle. I think they were 50 grain Blitz. I have seen 52 grain bullets key hole out of a factory .22-250 rifle. Every third primer was blown. Serious overload. Later! Frank