Loads for the .30 Carbine
Date: Mar 06 2018
When I first met my wife-to-be, Gail’s father had an Underwood M1 .30 Carbine and several shelves stacked with World War II surplus ammunition to go with it. On Saturday drives in the hills, I took along the M1 and an armload of ammunition. After several dates, Gail and I had shot most of her dad’s ammunition cache at cans and dirt clods and gophers.
That was more than 40 years ago, when surplus .30 Carbine ammunition was inexpensive and plentiful almost anywhere. The majority of that old ammunition has been shot, but commercial ammunition is commonly available to feed many of the 6.2 million M1, M2 and M3 Carbines produced for the U.S. military during WWII. This ammunition costs about 25 cents per round if made with steel cases, and 40 cents per shot for brass case cartridges. Those prices drove me to reloading .30 Carbines.
When handloading cartridges for the M1, I pay attention to bullets, powders and reloading techniques to produce loads that cycle the Carbine’s action and provide top velocities from a small amount of powder with relatively good accuracy.
The standard bullet for the .30 Carbine is a 110-grain roundnose. A handloader can vary some from that weight, but not from the round nose. My Underwood carbine was made in 1942, according to the year of manufacture and serial numbers listed on www.uscarbinecal30m1.com. It has a fairly smooth feed ramp, but the flat nose of Speer 110-grain HP Varminter bullets and the exposed lead nose of Speer 100-grain Plinker RNSP bullets hang up on the feed ramp and jam the carbine.
Roundnose bullets with a full metal jacket, or softpoint or hollowpoint bullets with their jacket fairly well enclosing the nose, feed without a hitch. Hornady used to make 83-grain FMJ and 93-grain SPRN and FMJ bullets for the .30 Luger. These bullets loaded with H-110 powder in .30 Carbine cases with an overall cartridge length of 1.665 inches feed smoothly through the M1. Velocity of the 93-grain FMJ bullets over 15.5 grains of H-110 was 2,241 fps. The same charge of H-110 fired the 93-grain SPRN bullets slower at 2,106 fps. Five-shot groups ran a touch over an inch and produced 2-inch groups at 25 yards. That’s not too bad for a Carbine with a trigger pull that has the creep and resistance of a jack handle.
Factory .30 Carbine ammunition loaded with 110-grain bullets have a stated velocity of 1,990 fps. That is close to the 2,000 fps for the same weight FMJ bullet loaded in military ammunition. The headstamp reads “PC 43” (Peters Cartridge) on my last batch of military surplus ammunition. The 110-grain bullets in those cartridges had an average velocity of 2,003 fps from my carbine’s 18-inch barrel.
The M1 Carbine is one of the few gas-operated actions that cycles reliably with cast bullets. My Underwood Carbine shoots well with bullets cast of Linotype from Lyman mould No. 311410. These plain base bullets weigh 127 grains. Muzzle velocity is 1,555 fps using 11.5 grains of H-4227. That load, though, does not always fully cycle the action. An additional grain of H-4227 increases bullet velocity to 1,691 fps and always cycles the action. Extreme velocity spread is a low 22 fps for five shots.
This plain-base bullet leaves a thin wash of lead in the bore after 50 shots, but it easily wipes out with a brush and a few patches. Every so often I take off the stock and in the barrel channel is a layer of bullet lube, powder fouling and flecks of lead that have bled through the gas port. The port has never plugged up though, and the carbine keeps chugging right along. A strip of aluminum foil was eventually placed in the barrel channel to catch all that gunk. That fouling could be reduced by casting bullets from a mould that produces bullets that accept a gas check, like the RCBS 30-115-SP, but a gas check adds a good 3 cents to the cost of each bullet.