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1/25/2018 7:38:29 AM
Posted: 11/12/2001 3:47:11 PM EST
Was shooting a new upper receiver this weekend and noticed something I had never seen before. The bullets were striking the target on their side. I didnt notice till I had already shot about 20 rds. I examined barrel and bore but dont see any problem. It is an 11.5 inch barrel with a 5.5 inch flash hider. I had another upper with me and it shot fine. Anyone have an idea what would cause this. Thanks
Link Posted: 11/12/2001 4:10:42 PM EST
Interesting. I recently purchased the same barrel configuration as you have. At 50 yards, I could keep all the shots on the paper, at 100, I could not even hit the paper.

I would also like to hear from other people with this configuration and hear about their experiences.
Link Posted: 11/12/2001 4:30:08 PM EST
Recently purchased BM 11.5" w/A2 FS, nary a problem with PMP 55gr. stuff. 1/9 twist by the way.
Link Posted: 11/12/2001 4:37:44 PM EST
[Last Edit: 11/12/2001 4:34:05 PM EST by LotBoy]
It's called key holing.
Link Posted: 11/12/2001 4:45:22 PM EST
[Last Edit: 11/12/2001 4:42:39 PM EST by markm]
Yes Lotman is right. keyholes are caused by the wrong bullet size for the barrel twist, a worn out barrel, shitty ammo, or some combination of the above. Also, bullets will keyhole at great distances when they destabilize.
Link Posted: 11/12/2001 5:09:49 PM EST
Not enough info to figure it out. What twist is the bbl? What kind of ammo were you using?

If the bullet is too heavy and the twist too slow, it could tumble. If the bullet is too light and the twist too fast, the bullet could break apart which could cause tumbling... a variety of things could cause keyholing.
Link Posted: 11/12/2001 5:14:18 PM EST
Got it, I was using 55 grain, with a 1/7 twist barrel, I dont think that would do it. Also I was only shooting at 25 yds. It was Wolf ammo which I have shot thru other barrels with no problems. Must be the barrel. Picked it up at a local show for a good price, now I know why. Anyone have an 11.5 inch heavy barrel they are looking to sell. Thanks
Link Posted: 11/12/2001 5:44:14 PM EST
Link Posted: 11/12/2001 6:12:01 PM EST
The CAR-15 barrels sold until very recently were 1 in 12 twist. 55 gr bullets should stabilize OK. Maybe it has an oversize bore. Does it keyhole with Federal 55gr?
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