AR feed ramp issue?

[gcoulsey]

Ok, so I'm nearly done developing this load for my friends AR-15,

So far I've been single feeding while testing etc
(the round is mag length, I single feed from habit)

Now I've loaded up some x10 shot batches to test tomorrow under normal
Firing conditions (using mag properly)
And I have tested to make sure the rounds aren't 'lengthening'
With the bolt slamming forward.. No problem there..
But I've found that all the meplats are getting bruised, and a nasty scratch down the side of the bullets you can snag your fingernail on..

I'm guessing it's a sharp edge on the feed ramp?
Is this common with ar's?
What's the fix, can I smooth it with a dremmel somehow or is it a proper gunsmith job?

 

[BCP]

Re: AR feed ramp issue?

I just cycled a few through mine and yes there are little scratches on the bullets. My 308 scratches the case necks pretty noticeably. If you wanted to you could stone the edges of the feedramps with some light sandpaper but I don't think it'll make any difference.

As far as hurting the meplat it could be that the tips (hollowpoint bullets right?) are snagging halfway up the feedramps. If it has rifle length feedramps instead of m4 cuts this can happen. Look here to see what I'm talking about:

http://www.ar15barrels.com/tech/feedramps2.jpg

I had that problem with my 308 upper and had to give myself M4 ramps with a dremel. Isn't pretty but it works well.

Also if you're in the UK is this a single shot build?

 

[gcoulsey]

Re: AR feed ramp issue?

Yes the meplats appear to be getting rammed pretty hard about half way up the ramp, and yes, 77gr Berger hollow points.

Not bothered about the brass scratches, but the bullet scratches look nasty.

Yes it's a single shot AR-15, you have to manually work the bolt every shot..
Not my idea of fun, but it's not my rifle!
It's a custom build, so I'm not sure if the ramps are standard, or too long, it's the first AR I have had my hands on.
I will check out your link, thanks