I understand there is a U.S. company manufacturing high quality M1 carbine magazines.  I understand it is $20 plus for a 15 round magazine.  But, hey, if it works it is worth it.  The problem is, I don't know the name of the company.  Does anyone know the name of the company?

I’m interested as well.  

BTT.

Is it the keepshooting.com brand?  I was going to get a few some time ago.  Their website seems to be filled with all kinds of positive reviews but I saw other users state they had problems with them.  I think it was on the CMP forums, maybe here.

IIRR those A/O  mag's are made by Promag

Overall I've been having good luck with the KCI 15 rounders. I've had a couple bad ones but taking them apart and checking the springs helped on 1.

Haven't bought any of the 30 rounders, so can't speak to those.

Bought 6 of the 15 round KCI Mags and 1 30-round from Brownells.  All worked well.

The KCI have last round hold open followers too which i like.

Avoid these at all costs. The KCI mags are better IMO

Promag blows. Unless they have improved the QC of their products since the magazines that I owned, I would avoid them and opt for some other company’s 5 round magazines.

I have never owned a magazine made by Promag that was worth putting in a gun

In my personal experience, just about every USGI 15- or 30-rd magazine required the magazine spring to be replaced.  Some OEM mag springs were rust-pitted, and almost worthless.  No sense trusting a +50-year old spring.

There's an updated, USGI mag-latch that is required for 30-rd mags, and is compatible with 15-rd mags.  Install the updated mag latch, and replace the mag springs.  Chances are you'll be OK, unless the mag body has been damaged.

Most M-1 Carbines should have all their springs replaced, at this point.  Most all the complaints about USGI carbines are due to very old springs. Replace them all.

I have about 30 USGI 15 round mags and about a dozen Korean 30 round mags. The Korean mags are good stuff, never a problem in any of my 3 M1 Carbines.

Find unissued in cosmoline ones. They should have a wax paper wrapper.

Under that grease is the best M1 carbine magazine ever made. You can find them as low as $25 with some digging.

I just got four more of the Korean mags, haven't had any problem with them. For that matter, I haven't had any problems with any of my 15 rounds magazines and they run the gamut from original WW2 to brand new Korean.

The M1 Carbine magazines aren't exactly complicated and I see very little physical difference in them. In fact if I'm shooting any type RN ammo, be it soft point, RNHP or FMJ, I can close my eyes, grab a magazine and it will feed.

For comparison (L-R) National Postal Meter, Korean and KCI (Also Korean!).

 

 ETA- If you're having feeding problems with your Carbine, I'd suggest disassembling the bolt. I have an Iver Johnson that doesn't want to chamber the first round out of a magazine unless one works the bolt with gusto; the extractor didn't want to snap over the rim of the cartridge. I ordered a bolt disassembly tool and took the bolt apart. It was packed with crud, especially around the extractor and its spring and plunger. After giving the entire bolt a good cleaning and reassembling the bolt and rifle, it now functions perfectly and I can pick up the first cartridge out of a magazine, ride the bolt about half way home then release it, and it will chamber a cartridge as it should.

I picked up a couple of mags from keepshooting.com.  Had issues with every single one. I have some newer mags that are stamped U on the back.  They look like USGI but are too new to be.  Anyway, never an issue with those repros.  Picked them up on eBay.

Source for good replacement springs?

I use these guys

Fulton Armory

Keepshooting mags are great. I just bought 4 more of the 30 rounders

Might not be a bad idea to replace all the other springs on your nearly 80-year old GI Carbine.  And the mag springs.

Quality springs wear out due to usage, and rust.  You can see the rust, but not the usage.

I suggest replacing all springs on older firearms, as a matter-of-course.  Buy them from trusted vendors while still available.

BTDT for many firearms.  FWIW, some previously commonly-available springs are no longer available.  Not to mention commonly-needed spare parts, such as extractors and so forth.

Snooze and lose.  Your rifle may be a single part away from being useless.

If Biden bans inter-State sale of firearms parts, what will you do?

Got mine.  Get yours.

I know the original post is from July but in case anyone is looking, here is NOS of USGI M1 carbine magazines at Century Arms.

USGI M1 Carbine magazines