Umarex Thompson M1A1 Part 5
Honest accuracy with fixed sights
By Dennis Adler
A CO2 powered BB air rifle will shoot with reasonable accuracy out to 10 meters, even beyond, but target accuracy is another story. Looking back at the Umarex Legends Cowboy Lever Action fired with Meisterkugeln lead wadcutter pellets through the rifle’s smoothbore barrel, my best accuracy at 10 meters was 10 rounds into 1.25 inches with a tight group of 8 rounds in one large hole measuring 0.5 inches edge to edge. I also shot with the Umarex Peacemaker BB cartridges and put 10 rounds at 1.625 inches with a best 5-round group at 0.5 inches. I then pushed the Cowboy Lever Action all the way out to 40 feet with H&N Sport Match Green 5.25 gr. alloy wadcutter pellets and printed an impressive 10-shot group at 1.125 inches with multiple overlapping hits and the best five shots at 0.562 inches. Of course, this was shooting pellets not BBs and the Lever Action is a lighter, longer barrel air rifle then an M1A1, which only has a 9-inch (internal length .177 caliber) barrel vs. a 19-1/2 inch internal length barrel. Being a lever action it also had no appreciable movement (no blowback action) and a very light trigger. Results were as expected.
While this is not an entirely fair comparison, aside from having a smoothbore barrel like the M1A1, the results thus far with the Thompson have been equally as impressive with a much shorter barrel. A more 1:1 comparison might be with the Umarex Legends MP40, which also has a 9-inch internal length .177 caliber smoothbore barrel. With this model I had managed a best 10 shots (fired from 25 feet instead of 21 feet) with overlapping hits and a spread of 1.18 inches. (A head-to-head comparison is forthcoming in another War Dogs segment).
It is a given that the M1A1 can hold its own at 21 feet against just about any CO2-powered BB rifle out there, semi-auto, select fire, or lever action. But now we want to know what happens to that accuracy when the distance increases to 10 meters.
Back in the WWII era, the one complaint soldiers had about the M1A1 (and Thompson models from earlier years) was its weight, which was about the same as the big M1 Garand, and its inaccuracy at ranges over 50 yards (46 meters). There was also the lack of penetrating power of the .45 ACP pistol cartridge at that range. In close quarters use, there were few complaints, though, and the U.S. military purchased a total of 1,387,134 M1 and M1A1 variants during WWII. With the 30-round double-column, double feed box magazine, the Thompson was a formidable weapon and it performed better than most under with exposure to rain, dirt, and mud combat conditions. I wouldn’t recommend trying that test on the CO2 model, but as an air rifle it seems to give one that impression of ruggedness.
10 meters off the shoulder and rested
With excellent performance from all three brands of steel BBs tested at 21 feet, I settled on the Umarex Precision steel BBs for the first 10 meter test of the M1A1. I took a chronograph reading with the Umarex before starting and about 30 shots since changing the CO2, velocity was hitting from 435 to 438 fps, so a little higher than earlier tests.
I fired a total of 10 rounds from the shoulder at a Shoot-N-C target with POA adjusted up 2-inches and about half an inch right to compensate for the added distance. My shots actually came in a little high and left, all hitting in the 10 ring with one clipping the bullseye for a spread of 1.056 inches, and a best five at 0.875 inches. I shot another 10 off the benchrest using a 10 meter pistol target and this time my shots came in lower and just a tad left, but with a tighter group measuring 0.875 inches for 10, and a best five at 0.625 inches. These would not be bad groups at 21 feet, let alone 10 meters, so again I am pleased with what the M1A1 can deliver. But there’s more.
I ran one last test shooting from a military-style kneeling position at 10 yards (3 feet closer) with 10 rounds of Hornady Black Diamond, which had been very accurate with the M1A1, and from this supported position the gun put at least five rounds into the same small area and blew out a piece of the target. Total spread measured 0.875 inches with smallest group measuring 0.437 inches. I really like this gun! If you haven’t got it on order, you should.
In the Part 6 conclusion, full auto fire and some authentic M1A1 accessories that work with the CO2 model.