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Posted: 6/2/2007 5:11:40 PM EDT
| First, many thanks for a great site. I have been lurking here a while and have learned a lot. I bought a Bushmaster M4A3 Patrolmans Rifle a couple of months ago and have put 500 rounds through it. BRD bit hard and I built another one. LAR Skeletonized lower, ACE skeleton stock, Fulton Armory slickside upper, RRA lower parts kit and Bolt group, and a Bushmaster 16" pencil barrel. All magazines are Bushmaster. My factory Bushy runs great with 55gFMJ, but will feed the 50g HPs with about a 95% success rate. I took my new build to the range today and it ran great with 55gFMJ, but wouldn't play AT ALL with the 50gHPs. Both guns have the older stlye feed ramp profile and when the HPs fail to feed, they hook the lip of the HP on the edge between the barrel extension and the upper receiver. The feed ramps in both guns are smooth without any discernable tooling marks. I searched a bit for suggestions about feed ramp polishing and came up empty. Is there a way to make these guns feed the HP ammunition reliably without major modifications to the feed ramps? Or is HP ammunition best left for those with M4 profile feed ramps? The HP ammo in question is American Eagle brand. Also, both barrels are centered in the upper receiver with the feed ramps in the correct location relative to the front take down pin. These failures to feed occur with all of my magazines. Thanks for your suggestions. |
| Thanks for the suggestions. I'm thinking I'll put a couple layers of tape on the back of a magazine and see if I can change the angle enough to feed and break it in. Failing that, I guess I'll feed the HPs to the Bushy and stick to FMJ after that. I bought 600 rounds of the HP and it's a bummer that it won't feed well. On the plus side, I'm getting lots of practice clearing jams and swapping magazines. |
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