Advice Needed: Polishing a Feed Ramp

[Devonai]

My M1 Carbine is not as reliable as I'd like it to be, and while I suspect the magazines may be the problem, it couldn't hurt to polish up the feed ramp.  Any advice on the best way to do this?

[HankB]

Don't use a grinding wheel in a Dremel tool!

Depending on what they looked like to start with, I've polished up feed ramps with abrasive-impregnated rubber polishing bits in a Dremel, and finished up with a felt wheel and Simichrome. The main thing to remember is don't take off too much metal, or get carried away and start hogging out the back of the chamber.

It's awfully hard to put steel back . . .

[AZRedhawk44]

My M1 Carbine is not as reliable as I'd like it to be, and while I suspect the magazines may be the problem, it couldn't hurt to polish up the feed ramp.  Any advice on the best way to do this?

Don't do it.

Or, at least don't do it until you spend $10 for a replacement mag spring to see if that fixes it.

http://www.gunsprings.com/index.cfm?page=items&cID=2&mID=98#536

[AJ Dual]

Do you have any .30 carbine dummies you can slow-cycle by hand while watching through the bolt/ejection port area to see where they're hanging up, and to test different mags?

But I agree, what looks like it's feed-ramp issues might just be a bum magazine not letting the round ride high enough.

Crushed feed lips or ones just too close together to meet the spec. could also do that as well.

[Devonai]

Thanks for the help so far.  I should have described the problem for you.

In both live fire and dry cycling, rounds have a tendency to hang up on the feed ramp.  I'd say 10% of the time.  The jam can be cleared by tapping the charging handle, but if the round still won't chamber then I can simply pull back the charging handle, tilt the rifle to let the round fall away, and continue firing/cycling.

I only have four mags right now, one 15-rounder that may be USGI, and three 30-rounders, all aftermarket.  Of these only one 30-rounder does not exhibit this problem.  Hence my suspicion that it may be a combination of crappy mags and a feed ramp that isn't as smooth as it could be.

Considering that the reliable mag was purchased from Cheaper Than Dirt for $10, I'd be just as inclined to buy more of those as I would to buy replacement springs.

I don't have a Dremel tool, but I suppose I should buy one eventually.

[MechAg94]

The CMP had been selling some mags also. 

I've had good luck with the 15 round mags sold in the little paper bags.  I think they are Korean.  Though I admit I have not shot my CMP carbines all that much since I got them. 

[AJ Dual]

I'd just gently pry the feed lips up/wider a teeny bit at a time and see what happens.

Spread them a bit wider, and turn the angle of the lips upward a bit too. Also, carefully compare the angles of everything between a suspect mag and one that works better.

The one that works better might be noticeably different by a millimeter or so.

[roo_ster]

I'd first replace mag & recoil springs with fresh new ones and see if that did the trick.

I have polished several feed ramps with success with the felt bullet-nose Dremel nubbin combined with jeweler's rouge.  Go slow, keep it even.  Do not polish enough to change geometries.

[AZRedhawk44]

I think you're being tempted by 1911-itis.

"Just polish the feed ramp."

I think you've confirmed that it isn't feed ramp because you have 1 consistent magazine that isn't subject to this problem.

The usual culprit if it isn't magazine related, is extractor.  But since you have a good magazine and a mere 3 bad ones, sounds like $30 worth of new magazines fixes the problem very easily. 

Hitting it with a dremel, especially if it's an old M1, may over do the job because someone else may have already tried the same thing 30 years ago.

[S. Williamson]

Heck, last ramp "polish" I did was on my Sig Mosquito.  Done with Simichrome, a single q-tip, and spent no longer than five minutes.  More like a slight brightening rather than a polish.

[TommyGunn]

Are you using ball ammo or soft nose/hollow point rounds?
If you are using soft nose that may be your problem.  It is possible that polishing the feed ramp (carefully as others have suggested) may help.  IF you are thinking of using the M - 1 Carbine for self defense purposes then using soft or hollowpoint rounds will improve the stopping ability of the weapon.
Remember the carbine was developed for ball ammo .... what we would call "FMJ" or full metal jacket rounds.
If you're using these and having problems, you DO have real reliability problems and should do something to help your gun, whether it be polishing the ramp or examining magazine issues.  But it is common for the M-1 carbine to have problems with soft nose bullets. 
Good luck with your carbine.