Question about M1 Carbine

It seems I’ve been seeing a lot of posts recently about M1 carbines. That made me want to get mine out and shoot it, which kinda lead me to this question. Should .30 carbine bullets touch the lands in the barrel when reloading? By that, I mean touching ever so lightly so that it might rub off marker ink, but not leave any permanent scrapes or marks on the jacket of the bullets. The reason I ask is that ammo seems to fit rather snugly in mine, and even factory ammo will leave little rub marks on black marked bullets, but not scratches. Everything seems to chamber fine, but this just causes me to wonder.

I’m not necessarily concerned with accuracy, but with safety. I worried that the bullet being too far into the lands would increase pressure. Conversely, if I seat the bullets deeper to avoid the lands, that would also increase pressure.

hdwhit said:

To directly answer your question, "No." The bullet should be engaging the lands of the barrel on an M1 Carbine.

For the record, what M1 Carbine do you have? How long have you owned it? And if you're not the first owner, did any of the prior owners modify it?

As others have noted, M1 Carbine 110 grain bullets vary in the profile of their nose and so may be slightly longer than others.

As other have already said, I used a factory Remington cartridge to set up my reloading dies and never had any problem with bullets from Remington, Speer, Sierra or Hornady.

I'm just envious of you that you still have your M1 Carbine.

Good luck.

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It’s a 1943 Inland. I bought it a couple years ago from Royal Tiger Imports. The barrel and receiver have matching dates 388xxx and 4-43. The bore is excellent to almost new. Apparently it wasn’t used a lot. After WWII, it apparently went to Ethiopia and sat stacked in a crate for 70+ years.Royal Tiger re-imported it and I bought it from them.

Thanks to all. I think a few people are misunderstanding what I was asking though. I’m not trying to make my bullets touch the lands. To the contrary, I’m trying to make them not touch the lands.

This morning, I did some further testing and found that my original concerns were indeed caused by Armscor bullets and factory ammunition. Hand loads with a 1.680” COL will not allow the bolt to close at all. Armscor factory ammo will allow the bolt to close, but not as smoothly as other brands. After measuring Armscor bullets and comparing them against Hornady and Speer bullets, they appear to be about .02” shorter and more blunt. The shoulder of the bullet sets higher as well instead of being a smooth curve from base to tip.

I also realized that when I originally checked my rounds by coloring them with a marker and chambering them, they were initially in front of the extractor. After that I checked my factory ammo again by placing it carefully behind the extractor and closing the bolt. It left the faintest mark on the colored factory Armscor bullet from touching the lands. These rounds measured 1.635” overall, so I decided to adjust my hand loads -0.01” to 1.625” overall. My dummy round at that length cleared the lands completely, and should have an equivalent seating depth to Hornady bullets seated to 1.645” overall.

That length is significant because some .30 carbine loads are compressed, so I ran some simulations on Gordon’s Reloading Tool. What it showed is that in order to keep the pressures the same as the published loads, I should only use a max charge of 14.5 gr Win 296/H110 or 13.7 gr IMR 4227 when using these bullets.

I think the factory Armscor will probably be OK as they chambered and locked the bolt, but were just touching the lands.

What do you guys think?

I don’t have a set of headspace gauges to check the headspace.

Update: I spent all night wondering how to check the headspace, and I finally hit upon an idea. I needed to check to see if anything over the the maximum case length would fit into the chamber and close the bolt, so I decided to size and deprime a 30 carbine case, and seat an 8mm bullet upside down. I had to stop and size a couple times while seating, and when it was flush, the case length was 1.315” long. I tried it at that length, and the bolt would not close, so I used my Lee quick trim die to trim the length. I stopped often and checked the length, and the bolt would not close on 1.300” or 1.298”, but it did close at 1.296” (although not smoothly). One more pass, and it closed smoothly at 1.295.

Checking lengths online, I found that military armorers used to consider 1.302” the absolute max for any reason, 1.298” the max for in the field, and 1.295 the max for barrel replacement. My numbers square pretty well with that information.

Here’s the pictures at 1.926”.