300 WSM AR10

I'm thinking polishing feed ramps is more involved than I thought it was going to be. The metal seems much harder than the small file I thought I was going to use. But this ramp could use some attention, or is this actually ok?
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Looks pretty sharp to me. Did you look at the chambered round after extraction to see if it is scratched up? Normally, I use a Dremel for polishing the ramps and go slow.
 
I use a high speed electric dremel with small diameter cylindrical fine grinding stones and finish to a mirror look with chrome wheel polishing compound. I buy the stones in packs because I go through them. I put some softer wood on the jaws of a vice and sit in a high chair and just go to work. It really doesn't take very long
 
I use a high speed electric dremel with small diameter cylindrical fine grinding stones and finish to a mirror look with chrome wheel polishing compound. I buy the stones in packs because I go through them. I put some softer wood on the jaws of a vice and sit in a high chair and just go to work. It really doesn't take very long
Gotta go get some. There was a chunk of copper, or brass, laying on the juncture when I got it apart.
 
Worked on the ramps last nite, took it out to see if that fixed it or not.
Nope, no celebrational cigar. Seems better, but it's hard to say, with no previous documentation.
Seems to be the right shell column. In every instance today, all involved an odd number shot. For a minute, I hoped that it was the fault, some how, of the brass catcher. No luck. Took it off, and saw two more malfunctions.
 

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I think You need more gas pressure. Or a lighter buffer or spring....looks like your bolt isn't cycling completely and you are double feeding and/or the bolt is riding over your rounds.
 
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How much can safely be removed between these arrows? I think I'd like to take little more off the right side. Thanks for any and all advice.
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See the scratches along the case length? That is likely from the feed ramp.
The dimple in the case neck is from ejection and is pretty common on ARs.
I am assuming this is a fired case.
This still does not address the reason the bolt is not coming all the way back after firing and ejection. You will have to figure that out at some point or the rifle will not function reliably. Just saying.
I never understood your answer about homebuilt, gunsmith built or factory rifle.
 
I still think the bolt is skipping over the cartridge base on the chambering forward stroke. One simple approach to try first is slightly lifting the magazine lips of the steel magazine a little to make the top cartridge sit higher so the bolt will catch it coming forward. For this the work the bolt assembly has to come all the way back under gas pressure so it can strip the round out of the magazine coming forward.
cohunts post is accurate. It is either under gassed for the reasons I listed before or the buffer spring is too strong.
 
See the scratches along the case length? That is likely from the feed ramp.
The dimple in the case neck is from ejection and is pretty common on ARs.
I am assuming this is a fired case.
This still does not address the reason the bolt is not coming all the way back after firing and ejection. You will have to figure that out at some point or the rifle will not function reliably. Just saying.
I never understood your answer about homebuilt, gunsmith built or factory rifle.
Sorry about the confusion. It is a home built, started as an 80%. I didn't build it, a friend of mine did. The ammo says it's NATO ,7.62 x 51 PPU 20 head stamped.
 
See the scratches along the case length? That is likely from the feed ramp.
The dimple in the case neck is from ejection and is pretty common on ARs.
I am assuming this is a fired case.
This still does not address the reason the bolt is not coming all the way back after firing and ejection. You will have to figure that out at some point or the rifle will not function reliably. Just saying.
I never understood your answer about homebuilt, gunsmith built or factory rifle.
Well sir, I'd really like it to function reliably. I appreciate any input you give.
 
Did you do the test with one round only in the mag, fire it and see if the bolt locks back? That is the first test, and will show if you have a low gas problem to fix, which is what it looks like to me.
 
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