The National Firearms Act of 1934 made owning a full-auto Thompson Model 1921A1 submachine gun next to impossible. Transferable models routinely command five-figure prices, and even the well-made semi-auto currently offered by Auto-Ordnance/Kahr Arms is illegal in some states. It can also be expensive to fill a 20-round stick magazine or a 50-round drum with .45 ACP ammo, and in California, Hawaii, Massachusetts, New York, New Jersey and Maryland, these extended-capacity magazines are forbidden anyway. But, roaring to the rescue like FBI agent Melvin Purvis in a ’34 Dodge, comes The Chicago, a drop-in 6061 aircraft-grade aluminum and steel Tommy gun kit by Scottwerx for the ubiquitous Ruger 10/22.
“I love the 10/22 and have owned all the variations,” says Craig Scott, the kit’s inventor and talented design engineer with more than 30-years experience in the automotive and motorcycle industries. “And like a lot of shooters, I’ve always wanted a Thompson. Then, one day I saw a ProMag Industries 10/22 drum and thought, ‘That would be the hardest part to make for a .22 Tommy gun, and it’s already in existence.’ So, I got this crazy idea to turn my Ruger 10/22 into a semi-automatic .22-rimfire Thompson.”
Now, after a year and a half of development, The Chicago is perfected. Because it utilizes an existing 10/22 action and barrel, no FFL is required. And you can easily return your 10/22 back to the original configuration. Assembly is so simple, even I was able to do it without injury. It took less than an hour to transform a 10/22 into a M1921 rimfire, and Scott actually put one together in 10 minutes.
“All manufacturing tolerances are held to 2/1000s of an inch, the same criteria used to produce motorcycle and automotive components,” noted Scott. “Every-thing screws together, lines up and fits exactly like it’s supposed to.”
The only tools needed are a hammer (for peening the two trigger-group pins), a screwdriver and a punch. Everything else is supplied, including simple 10-step instructions and a set of socket wrenches for tightening the replacement screws. There is no drilling required and all the hard work—machining, inletting and precise fitting—has been done. The buttstock, pistol grip and fore-end are attractive American walnut pre-selected for matching grain. A converted 10/22 gun weighs 7 pounds, less than half the weight of a real .45-caliber Thompson.
Ruger’s front sight is retained and the rear sight, held by two screws, allows for slight windage and elevation adjustments. The rear sight almost doubles the 10/22’s sight radius, increasing the gun’s accuracy; I was bouncing tin cans at 100 yards. But, even with the Scottwerx pseudo-stick and drum magazines, which ingeniously incorporate Ruger’s 10-round rotary mags, this Thompson look-alike is still mechanically a 10/22. So, although there is an uncontrollable urge to rapid-fire The Chicago, the sluggish trigger proves to be a hindrance. Consequently, I’m customizing it with a Volquartsen TG2000 competition trigger for a crisp 2.2-pound let-off. I’m sure that’s what Agent Purvis would’ve done.