Side bolt M1 or Top Bolt Commando?

M1, naturally. Of course, I've just got this "thing" against vertical foregrips, so...

you should get the back one I have a 1927a1 civilian legal Thompson and love it. But just be sure to run full power 230 grain loads through it. [uzi]

The nice thing about the Thompsons is that they're so heavy you can take out an assailant at close range by just dropping it on their foot.  They make a pretty good club, too, if the barrel is not too hot.  [:D]

I have a 1927A1. I replaced the verticle forgrip with the M1 model forestock. You can order it off of Auto Ordinance's website, and the piece drops right in. Also, dont bother buying any 30 or twenty round mags from Auto Ordinance (now khar arms), they cost way too much. Instead buy the mags surplus for around $10-$12 each. Take a dremel tool, and enlarge the hole in the back until it locks in the mag catch. This is all Auto Ordinance does anyways, except you pay over $50. for their surplus mags that are modified.
I use 230 lead round nose bullets from national bullet co. These have the exact profile of the FMJ bullets, but cost less than half. Use shooters choice lead solvent to clean the bore.
All in all this a nice close range blasting gun! If I had to buy it again, I would buy the M1 version. But the finned bbl is kinda neat too, maybe I'll just have have both!

FYI,The Numrich arms building sits right accross from Auto-Ordance.I wish I still had my fin barreled Tommy gun I purchased there over a decade ago.The most suprising thing about the gun was the amazing accuracy.By the way this is my first post,I've been lurking a few weeks.I really like this site.Best Regards,Ralph

I've heard the Thompsons fired from an "open Bolt".  Can someone explain what that means?  The freakin' bolt can't really be open can it?

I think I can answer that one, Attman.  Open  bolt means that the bolt is heavy enough to retard the action long enough for the bullet to exit the barrel.  Thus, the bolt have not have to lock in place before each shot.  Most .22 to .38 plus some subguns in 9mm and .45 = open bolt  
     

Kinda sorta. Several guns fire "open bolt" in full auto, the UZI springs to mind.

Open bolt means that the bolt is held back, or "open", by the sear rather than the bolt catch like on an AR.

The bolt is released upon pulling the trigger & it travels forward into battery allowing the firing pin to hit the primer as it stops into full battery. It will then move back upon ignition of the powder & only lock back when the trigger is released or the mag runs dry.

The US military machine gun, M-60, is also open bolt.

attman: open bolt means that the bolt has a FIXED firing pin, the bolt is latched back buy just a holding sear "NO HAMMER" the bolt when released slams forward while doing this the shell is stripped from the mag, has soon has the shell chambers the shell fires! M16/AK47 etc! usually uses a closed bolt means it has a locking device, a movable nonfixed firing pin that a HAMMER strikes. one more point an open bolt is illegal to posses unless you have a registerd SMG or a old open bolt MAC10 that came with the gun. my Registerd MAC10
SMG fire's from an open bolt.

Open bolt is pretty much reserved, for full auto. the bolt goes back and forth until you release the trigger and stop it. A closed bolt, shuts on the chamber and the hammer hits the firing pin. this resents, the H&Ks as the MP5  are about the only full auto that is a closed bolt.
I did order a M1 Thompson, thanks guys