Thompson envisioned a "one-man, hand-held machine gun" — a weapon with a high rate of fire that didn't need range or accuracy, because inside a trench you were never going to shoot very far anyway.

That's essentially the same design philosophy behind every modern PDW and SBR on the market today. The requirement didn't change — the metallurgy and propellants just got better. Thompson had the concept nailed before the Treaty of Versailles was signed.

Its use there led directly to the creation of four-man fire teams that could generate as much firepower as a nine-man rifle squad — a doctrinal innovation with lasting implications for small-unit tactics.

People forget the Thompson didn't just influence gun design — it changed how we think about building a fighting unit. That four-man fire team concept is alive and well in every branch today. A submachine gun proved it out in the Nicaraguan jungle in the 1920s.

In the Pacific and Asian theaters... the weapon's weight and the difficulty of supplying .45 ACP ammunition eventually led Australian units to replace it with Australian-made submachine guns — the Owen and the Austen — in 1943.

Logistics beats ballistics every time. The .45 ACP debate gets endless forum threads, but if you can't get the ammo forward, the caliber argument is irrelevant. Same conversation happens today when someone builds a 10mm AR — love the round, good luck keeping it fed at a remote post.

"It has worried me that the gun has been so stolen by evil men & used for purposes outside our motto, 'On the side of law & order.'"

Thompson wrote that and died before seeing what WWII paratroopers did with his design. The man who invented the term "submachine gun" never got to see his gun used the way he intended. That's a rough way to leave the world.

A U.S. Army Special Forces soldier... described keeping six Thompsons locked, loaded, and ready for base defense at a camp in Vietnam in 1963 — valued specifically for the .45 caliber's knockdown power at close range.

By 1963 the Thompson was officially obsolete and being phased out everywhere — and SF guys in the field were still hoarding them for close work. That tells you something real about the difference between what gets replaced on paper and what stays in the gun rack when things get serious.

If you've shot a semi-auto Thompson — the Auto-Ordnance versions you still see at gun shows — how did the weight and balance feel compared to other pistol-caliber carbines you've run, and did it change how you think about the original design?

Read the full article in The Handbook → | By The Boise Gun Club Team