Modifying AR15 feed ramps

[SnkBit]

I've got an issue with a rifle I've been working on. I'm shooting 75gr Hornady HPBT's and the projectile is snagging on the sharp edges where the feed ramps are cut to allow the lugs to pass through. Basically wedging itself into this square cut passage. Is it ok to soften these edges? Is this common? I've had nothing but hell trying to feed this rifle.

 

[pagana]

Re: Modifying AR15 feed ramps

The only truly important area are the lug engagement surfaces themselves, so yes, you can soften the edges with an edm stone. It sounds odd that the bullets themselves would be snagging in this area however unless there are some terrible burrs as well. The sympton souonds more like the bullet tips are hitting the back of the barrel in which case see how much chamber lead in is there (should be no larger in diameter than the diameter of the bolt body). If the lead in is OK then try stones to soften the areas between lugs making sure there are no burrs left. While your at it, use the stone to soften the tops of the 2 lugs on the extractor side of the bolt to minimize the dings and scratches you are probably seeing on the case necks.