In reality, the Glock 21 is actually one of the best, and most affordable, .45 ACP pistols on the market. The Glock 21 carries thirteen rounds in a double stack magazine that is wider than the ...

45 Auto, also known as 45 ACP is a beefy cartridge developed in 1905 by John Moses Browning. Glock has a new take on that cartridge, melding a relatively modern design with the 115-year-old round.