Good evening all!

So I found a lightly used M1 Carbine a few weeks at a pawn store.  Overall externally it looked fine, strong forge marks, no wood or metal dings.  It's an Iver Johnson, about late 1970s production.

Took it to the range and had several problems.  Up front, I have 2 30-round magazines (1 appears to be the M2, bolt hold open, style).  I was using Remington ball, new in box.  I also tried a few Federal SP, new in box.  

1.  Far and away the most frequent problem:  Numerous failure to fire - the bolt either went click (and left a light primer strike), or didn't fire at all.  This happened both after shooting a first round, or occasionally when releasing the charging handle on a new magazine.
2. Several rounds of the Remington blew primers.
3. A few failure to feeds - I have several 15-round mags en route to try out.   This was mostly on one magazine, the last round, so I'm thinking it's a mag issue.
4. Rarely the bolt hasn't closed on the chamber with a round in it.  

My thoughts are that it's got to do with the hammer not cocking all the way.  I can hear a hammer 'click' on an empty chamber, every time I cycle it.  But both when charging the rifle (so I don't think it's a gas problem), and after firing a round, I've had the failure to fire and light primer strikes.

Thoughts/suggestion?  Thanks in advance.

Replace the bolt.

I suspect you have a vert dirty chamber that is making it difficult for the action to fully close and lock the bolt. M1 carbines have a firing pin bridge safety built into the action. This firing pin bridge safety is supposed to prevent the firing pin contacting the primer if the bolt is not fully locked. When you get your failure to fire, the hammer is hitting the firing pin, the bolt is not completely turned into the locked position,  the tail of the firing pin is interacting with the receiver bridge, which cams the bolt into fully locked position, but slows down the firing pin enough that the primer does not go off.

The popped primers are a little worrisome. They could simply be issues with those particular loadings or brass. Popped primers are also a potential sign of excess pressure. Extreme carbon build up in a chamber can cause an increase in chamber pressure. If the popping primers still happens after a thorough chamber and bore cleaning, then get the headspace checked. If  headspace is okay, use different ammunition.

A new recoil spring would probably help with the feeding issue.

Good luck.

I think you need to check the headspace

Fulton Armory ok, or drop the extra cash for an Underwood?

Oh, I finally found a pic of the hammer- mine seems to have a crack in it...

Headspace, any suggestions on gauges?

Clean the chamber, and also, clean the bolt.  If the extractor spring is gummed up it won't allow the extractor to slip over the case rim, and that could be slowing down the bolt.  Measure your recoil spring.  It should be no shorter than 10 1/2".  New GI springs tend to run 11 - 11 3/8". Quite frankly if the gun is from the 70s and that is the original spring, it needs to be replaced.  Period.  A weak spring will cause the symptoms you describe.
You might find mil surp springs labeled "Hi Speed", and those are probably good to go.  Be leery of the Wolf Extra Power springs.  They often cause more problems than they solve.

For feeding, the mags seem like the culprit.  And the FTF's, I agree with tearing the bolt down and cleaning and replacing springs.  And yes, replacing the OP slide springs.  I think orion 7 has the.  I forget where I got mine last time.....  www.billricca.com is another good source of USGI parts.  

But those 30 rounders are notorious for not working well.  Supposedly only USGI one and Korean ones work and I think it's hard to tell the copies....  I have 2 marked M2 on the back and they're just duds.  One of them, works sort of well until you get down to the last 7 rounds.  Then it starts spewing unfired rounds........  

I have had good luck with USGI  15 rounders of any flavor and condition.  Although admittedly, my Carbines never ran as good as my AR's.  Which is why I don't trust them like I trust my AR's.  Getting proper op slide springs made a big difference in a positive direction for me though.  But I also rebuilt the bolts when I first got mine.   And BTW, it's a PITA without the tool or 3-4 hands.

If you do plan on tearing the bolt down then spend the money for the bolt tear down tool.  It will save you a lot of headaches!

https://www.gunpartscorp.com/products/544250

If you are using 30 rd magazines, you should have the mag release that is designed for the 30 rd mags. It has and extra part on the left side that helps support the 30 rd mag that often gets out of position due to its weight.

also, I grease my Carbine just like a Garand, give that a shot as well as replace your springs.

Just an update

Ordered some springs and a new hammer as well as a bolt disassembly tool.  There appears to be small flecks of metal in the bolt carrier, occasionally blocking the firing pin at the hole where it impacts the primer.  I suspect this is most of the issue.

Sounds like your leaning the right way. Probably fix that hammer and give the gun a real good cleaning to include the bolt,  gas chamber and chamber. You might be able to find a GI spring kit which includes the above mention recoil spring and a few others for under 30 bucks that might be worth changing.

After all that I would take it out and shoot it. If you have a 15rnd magazine, start with that. Plus some factory ammo.

Head spacing might not be a bad idea after all that is done.


Now let's see some pictures!