M1 Carbine questions

[cabezaverde]

How hard of an alloy are you guys using in your carbines?

Gas check needed or not - any mold suggestions?

[Outpost75]

Accuracy of my cast bullet loads was better than militaryFMJ or commercial soft points. My most accurate cast bullet loads, used Accurate 31-100T cast 15 BHN and sized .311” with Lee Liquid Alox and 7.4 grains of Olin AutoComp, metered with the RCBS Little Dandy Powder Measure Rotor #9. This load is not full power, but cycles the carbine reliably and drops the brass at your feet where it is easy to find.

A satisfactory full-charge load with 31-100T is 14 grains of IMR4227, measured with RCBS Little Dandy Rotor #18. This approaches the velocity of factory ammunition, shot to the same point of impact as factory loads and didn’t lead, but was not the most accurate load. The same #18 rotor meters about 13 grains of IMR4198 which functions the carbine reliably and was my most accurate load fired in the M1 carbine, with the Accurate 31-120TG bullet, without the GC.

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Pay careful attention to eliminate any cases shorter than 1.28,” or longer than 1.285” which may cause failures to lock. Starline brass is held within 1.280- 1.285 inches and I recommend that you do likewise with yours! If your .30 carbine brass is uniform, and of correct near-maximum length, there should be no functional issues. Dies for the .30 US Carbine use a taper crimp, NOT a roll crimp, which affects headspace of the case mouth against the stop surface of the chamber.

Case length should be checked EVERY time cases are sized. I use the Lee Quik Trim, which uniformly trues brass to 1.280+0.005/-0.000 after sizing. I cannot recommend the simple Lee case gage, trimmer and lock stud, because the locating pin is now machined integral to the length gage, rather than being a press-fitted, hardened nedle bearing as it used to be. When run under power in a drill press, as many of us used to do, the pin end wears now, so that consistent length cannot be maintained. After trimming as few as 100 cases the integral pin of the length gage snaps off.

Small Rifle primers should be used in the .30 carbine.

Cast bullet diameter is limited by chamber and brass dimensions to no more than .310” in most US carbines.

I also load .30 carbine for a Ruger revolver dates from 1977 and came with .310 cylinder throats from the factory. With cast bullets my Ruger revolver groups about as well at 100 yards as my WW2 Inland GI carbine! Best grouping of jacketed bullets is with the .309” diameter Hornady XTP, intended for the 7.62x25 Tokarev or .30 Mauser. The jacket thickness, skiving and cavity geometry of the XTP jacketed bullets enables them to perform well at the full range of velocities obtained from the .30 Carbine Ruger and the M1 carbine.

For full charges” in the .30 Carbine a case-capacity charge of Hodgdon or IMR4227 is satisfactory. I found that 4227 gave more uniform velocities than either #2400 or H110 which are often recommended. But my favorite load is 7.4 grains of Olin AutoComp, using exactly the same bullets and charges I load in the 7.62x25 Tokarev for my Cz52 and TT33. While AutoComp doesn’t give the highest velocity when fired in the longer barrel M1 carbine, it equals the velocity of full-charge GI loads, fired from the 7-1/2 inch Ruger revolver. It does so with less muzzle flash and blast, and better accuracy using less powder. So, what’s not to like?

K.I.S.S. Principle!

[Texas by God]

My limited experience has been good with 110gr psp PPU bullets and Lee C309113F made of wheelweights sized .309” over Win296. The charge for the cast boolit sooted the cases so it will be increased next batch. Accuracy and function are perfect so far in my wife’s Japanese M1.

[Larry Gibson]

I've been using cast bullets in M1 carbines since '68. I most often used just COWWs (+ 2& tin the last 20 years) which run 12 - 14 BHN when air cooled. For many years I've preferred to use a service cartridge velocity level load as that most often regulates to the ranges on the sight. Thus I prefer a GC'd (usually Hornady's) cast bullet sized .309 and lubed with 2500+ or an NRA 50/50 lube. I load them over H110 to 1950 - 1850 fps with 105 - 118 gr cast bullets. Accuracy in my carbines has always been better than any milsurp ball and usually as good as commercial factory or reloaded jacketed ammo.

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With my "shooter" M1 carbine (pictured) I can usually manage a 15 round mag into 2 - 3" group at 100 yards. I used to be able to do that with issue sights till my eyes went south......

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[ShooterAZ]

I also use BHN15 for 99% of my loads, typically from mixing 75% WW with 25% Lino. All my M1 Carbine molds are gas checked. My favorite M1 molds are the RCBS 30-115-SP, and the Lyman 311359 lubed with White labels 2500+. I load them with 10 grains of N110 (most accurate), or 13 grains of IMR4227. I size to .309 or .310 depending on which M1 I'm loading for at the time, my Inland has a tight chamber. If the loads are to be used for hunting I'll soften the alloy a little with PB and HP them using the Forster tool.

[Old School Big Bore]

The only cast I've tried in my Inland carbines were some copper-colored 110s (looked like Lubaloy but probably weren't) that I got in a trade - they promptly soldered the tappet. Had to dig that out on the firing line. Kind of afraid to try cast in 'em again til I get set up for PC, which will be a while because a friend left me a K of 110 FMJ and I'll exhaust those first. The Blackhawks however really love cast boolits. I treat them like .38s or .32-20s with the 311410 or M-P HBWCs and a little HP38. Maybe I'll make a batch of harder 311410s and see it they'll work in the carbines.

[jimb16]

OSBigBore....I've owned 24 carbines over the years and shot cast in all of them including a full auto M2. Only one of them did what you described. That was a Saginaw. Don't know why, but I suspect it was a burr on the gas port. None of the others showed any tendency to lead the barrels. I don't ordinarily say this, but if I were you, I'd pull the piston and run a properly sized drill bit up through the gas port to clear any burr that might be there. You shouldn't have any gas cylinder leading with a carbine whether the bullets are coated or not.

[georgerkahn]

My favourite .30 carbine mould is a Hensley & Gibbs #250 4-cavity 113 grain GC mould. The gas check keeps barrel clean and lead free, imho.
geo