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Posted: 10/14/2011 7:14:14 AM EDT
| Was out shooting some different hunting loads over the weekend (LR-308 AP4), and noticed that chambered rounds had some damage to the tips of the bullets. The lead soft points were the worst, with a significant flat "wiped" onto on side of the bullet (feed ramp contact?). Accuracy wasn't terrible (~2 moa), but it seems like it sure isn't helping anything. I guess it's not too surprising, as the chambering sequence is probably kind of violent from the bullets perspective, but is this something that I just have to accept? What hunting bullet type is most resistant to tip damage? Do polymer ballistic tips hold up? |
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Quoted:
Do polymer ballistic tips hold up? I have a DPMS SASS rather than an AP4, but I was curious about possible damage to ballistic tip ammunition, too. To test it, I loaded a some mags with a few different types (SST, A-MAX, GMX, and a couple others I can't recall) and cycled them through the gun both through these methods: 1. Load the mag, insert mag, relase the bolt, fire the round and allow the gun to cycle, then eject the unfired round. 2. Load the mag, insert mag, use the charging handle to slowly load the round, press the forward assist, then eject the round. Both methods showed abrasion on the bullet ogive (apparently resulting from the feed ramps), but none of the tips appeared to be affected at all. None of them were bent or showed any sgns of abrasion. ETA: The only one of these rounds that I would not use again is the GMX. Mine were loaded by Black Hills and they grouped well, but consistently left of POA by nearly 4MOA @ 100yds. |
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One thing to remember when doing that is to push the cartridge to the center of the chamber when you are extracting it so the ejector doesn't slam the bullet into the back of the locking lugs.
Lots of ejected unfired rounds will have two "chatter" streaks along the neck of the brass and the bullet, that is caused by the ejector spring trying to fling the round out before it clears the extension. I put my palm under the empty mag well and use my finders of my left hand to hold the round straight while pulling the charging handle back with my right hand. Then when the round is clear of the barrel extension I let it drop into my hand and let the bolt forward. |
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There was a post on here some where that the OP had pictures of where the points of the bullets were
striking just inside of the feed ramps on either side. He had to take a tapered stone on a Dremmel Tool and widen the feed ramps. Use a marker pen and try coloring this area, then hand cycle a mag. of FMJ and see where the marks are. 
Jack... 
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