Can you polish the feed ramp of an AR for feeding reliability?

L

labgrade

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Curious.

I've a Colt Match Target Competition HBAR that seems very prone to feeding difficulties & that probably due to cleaning - maybe.

Glitch comes into play only when I've fired sometimes as few as 50+ rounds & let the rifle sit for a bit - not cleaned.

Extraction's (& every thing else) never been a problem - it's always on feeding a round where all "works" enough to allow the hammer to drop, but the round's not chambered enough to allow a "bang." I'd have to to forward assist & then (obviously) re-work the charging handle to reset the hammer. Kicks the "chambered" round out & we get to start all over again.

Doesn't appear to be magazine related as it's happened with every one of 'em I have (supplied kindler & gentle 8-rounders, mil-spec Colt 20s or various & Thermold 30s). As mentioned, seems more of a "clean gun" thing.

Looking at the feed ramps, they appear to be pretty rough compared to any other semi I own. Can they be polished, or? for better reliability? Or - What else?

Too, unless I'm crazy (a distinct possibility) ARs have two feed ramps - one for each magazine position - don't they? Something I never really noticed before ....

Bought this rifle as a (ahem) "battle rifle thing" & although it is accurate & a yada, yada hi-cap, it is not in any way reliable enough. Every other rifle I own at least goes bang when I pull the trigger ....

FWIW, I'm shooting (mainly) new Federal American Eagle 55 FMJ, same-same 50 HP & various other "mil-spec" ammo .... have not seen anything ammo specific re this failure to feed.

Anything, other than keeping this darned thing "way clean" I can do to improve reliability?

Appreciate any feedback on this. If nothing else, it'll give rise to a few more comments re "ARs suck re reliability" due to that damnable gas system .....
 
The only FTFs I've had with my Bushy were mag related.

I just looked at the feed ramps on mine, and they're pretty smooth. Don't see what it would hurt to use the aproriate felt tip and some jeweler's rouge to smooth things up if you can see that the ramps are rough.

My dremel is not variable speed, and the high RPM slings all the goo off the felt tip before I can get close to the target. I use a cordless drill instead. Actually, I use rubbing compound instead of jewelers rouge as well.

Has worked well on the feed ramps of three 1911s. You just have to find a felt tip bit that is the right size and shape.

Match Target Competition.

Your problem sounds more like a tight chamber. When I have a failure to feed, the round is mangled and un-usable. Your problem is that the round is being chambered, but sticking in the chamber. Is the chamber chrome lined? maybe the chamber needs polishing. Just guessing here, as I seldom know what the hell I'm talking about.
 
Carbon buildup is the trigger of the problem--- after it sits, it absorbs moisture and concretizes (and becomes corrosive---clean it immediately after firing).

If it's humid, the heat off the weapon will concretize it.

Shoot it more, it will loosen up. Switch to a chrome bolt carrier, it will loosen up.

Could be any part that's tight--chamber, carrier, etc. But wear will loosen it. Also check the spring tension on your action (buffer) spring.
 
I don't think the bullet point ever hits either of the feed ramps... Mine seem untouched...

It's a lube thing probably. Just needs a little tuning no major mods.
 
What are you using for lube?

Ar15s and M16s work best wet. Get some milspec CLP and lube the bolt carrier.

Check and see if the carrier key is going over the gas tube straight. It could be you've bent your gas tube a little and it's hanging up on the carrier key.

Unless you're already lubing it well, I'd say that's your problem.

Jeff
 
Check the locking lugs and the chamber.

Make sure that they are clean and free of carbon. Also, fully disassemble the bolt carrier group. Clean and scrape the back of the bolt until it is carbon free. Clean the inside of the bolt carrier, too. You should see clean metal when you look down inside the bolt carrier. (Not shiny, just clean.) If you don't, some carbon must be removed. Brownell's sells a reamer built specifically for this purpose.

Also, polish the inside of the charging handle and the top with 600 grit sandpaper. Finally, stone the rails on the bolt carrier until they are gleaming. Oil with a light coat of good oil, and don't forget to lube the locking lugs, and the bolt itself.
 
Geez. The guy asks a question & never comes back. :rolleyes:

Thanks for the feedback, folks. Finally had a chance to start digging into this & play a bit.


AR-10,
"Is the chamber chrome lined?"

I don't have a clue. Shining a flashlight down the bore & it doesn't seem to be too shiney. SN's CCH 005XXX any ideas?

DeBee,
"I don't think the bullet point ever hits either of the feed ramps... Mine seem untouched... "

Mine too. Just wondering


Jeff White
"What are you using for lube?"

Break Free CLP

Powderman
"Also, polish the inside of the charging handle and the top with 600 grit sandpaper."

Inside of the charging handle makes sense, but why the top?

BTW, a variable speed Dremmel W/a mandrel-mounted Kratex works wonders for very light material removing or polishing - depending on the grit used.

& thanks, dz, for that other link.
 
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