people have made that mistake for years. While the range and penetration of the Thompson is generally denigerated, it did have an exceptional range considering it was a pistol round. However, the accuracy was not that great beyond a 50 meters. The 10 1/2 inch barrel just wasn't up to the task, it was a "lead pump" first and foremost. That said, here is a portion of an interesting report (Philip B. Sharpe review of the M1928A1 Thompson from 1929): "This .45 automatic pistol cartridge, in the arm designed for it, delivers about 810 foot per seconds velocity. In the 10 1/2-inch barreled Thompson it delivers about 925 f.p.s. Tests indicate that accuracy and penetration is quite respectable, even at the longer ranges. A single shot two feet from the muzzle, using the 230 grain bullet, tested on 3/4-inch yellow pine boards spaced one inch apart, ran through 6 3/4 boards. At 100 yards it would plough (sic) through six boards; at 200 yards through 5 1/4; at 300 yards, 4 1/2; at the 400 mark through four boards, and at 500 yards it could still stumble through 3 3/4 boards¾sufficient to cause very unpleasant sensations in the body of a recipient." [Page 1107] It could "reach out there" more distance than I would have assumed, but I have NO idea where one would have to aim to get the bullet to that distance! 500 yards! Another poster (lwd) did the calculations, and I seem to recall him coming up with aiming to compensate for about a 45 foot drop at that distance. But since the rear sights (on the early models) were calibrated out to 500 yards it probably wasn't as hard to do as one might think.