I have two IBM m1 carbines. I've replaced all the springs and curiosity got the best of me about headspacing. The Go gauges work on both, the No Go works on my newer one. I have tried 2 different NoGos and the field gauge on my older carbine and the two bolts I've tried goes into battery on all three gauges. I bought another bolt and it's on it's way. Those two bolts also fail the NoGo gauges on my newer carbine. If the third bolt does not work am I looking at a rebarrel? As far as I know the older carbine worked fine when I bought it..

While rebarelling would be optimal, I personally would not be too concerned about slightly excess headspace on a M1 Carbine.

It's a low pressure, nearly straight wall cartridge. Even if it's a bit outside recommended headspace, it shouldn't create a pressure issue or safety concern.

It would have to be grossly off to be a safety concern, and since it headspaces on the mouth, the firing pin likely would not fully contact the primer causing misfires/light strikes before other issues cropped up.

If you reload, you could even trim your cases slightly long to address this.


And you do have the barreled receiver totally field stripped and the bolts stripped bare when checking headspace, right?

^^

Used both Forster and Clymer gauges, the bolts were stripped with the Field and Clymer brand gauges

I haven’t shot my M1 Carbine in a while, it’s got that handy HD feel. It reminds me of a 10/22 with the power of a 357 mag.

quote:

Originally posted by sourdough44:
it’s got that handy HD feel.

With an Ultimak rail, a red dot, a light, an adjustable 2 point sling, Hornady Critical Defense .30 Carbine rounds, and some known reliable magazines, a M1 Carbine is a perfectly acceptable home defense gun, even in 2026.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
I completely agree. The M1 is the perfect house gun.
Its light, fast to handle, and more than capable as far as bullet energy.
I feel ashamed that I don't give it the credit it deserves by leaving it in the safe and not doing the job I feel it can do, while always choosing something else to do this job.

Who do you recommend for new springs? Wolff?

Wolff or new old stock USGI.

Wolff makes a complete kit, makes it easier if you have the bolt tool for those two springs. The hammer spring can be a bear. Theres good vidios on youtube. There 3 smaller springs for the bolt release,extractor and sear that might be confusing.Need to count how many coils there are on each to match them up.

quote:

Originally posted by valkyrie1:
Wolff makes a complete kit, makes it easier if you have the bolt tool for those two springs. The hammer spring can be a bear. Theres good vidios on youtube. There 3 smaller springs for the bolt release,extractor and sear that might be confusing.Need to count how many coils there are on each to match them up.

^^^
Thanks

What Rogue said about trimming the cases a little long works. The M1 carbine likes to stretch out cases anyway. I have never had to trim cases as much as fired M1 carbine cases. Brit Enfields come in second place from what I have experienced in years of reloading and shooting Mil-Surps.