MadDog

Most manufacturers add the charge of what a separate barrel costs and add their gunsmith charge for a barrel swap. Doesn't make sense since the SBR models usually have the short barrel already installed at the factory and no additional work needs to be done but that is the way it is priced. Bottom line is they charge a premium because they can. That is why I SBR'd my own.

The ring sight I got from Thompson Barrels was made to Colt specs and turns out is the proper height. My first shot off hand at 25 yards (indoor range) was dead center on the X (couldn't have been more accurate bench rested). For crude sights this is very accurate. The ring sight was a very loose press fit. I put red locktite on both surfaces, slid the sight on, trued it up with a level and square, and let the locktite dry. I figured if the sight was dead on I would drill and pin the barrel afterwards. My first Gi mag had a couple FTF's, my second GI mag had a couple of FTF's and my Kahr mags had a few FTF's. apparently a barrel made to true Colt specs has a tighter chamber then the Kahr barrels. After about 120 rounds it started to feed reliably. I loaded up a 50 round drum before I went to the range but was not gong to try it when I hade the FTF's as drums are a bitch to remove with jammed up rounds. Drums are also a bitch to empty without shooting up the ammo so I tried it out. To my surprise the drum runs 100% even rapid fire. Turns out the rounds have a "straight feed" with the drum where as they have to hit the top of the chamber and angle in with stick mags. All in all I am very pleased with this SBR project and will now drill and pin the ring sight on. Now to start my next NFA project (SBR my Wilkinson Linda pistol).

I am waiting for my Form1 to get approved and thought I would do some research in the mean time. I want to do the barrel swap myself so I though I would ask if anyone has done the work themselves that could answer the following questions. Are the barrels right hand threaded, meaning they back out of the receiver counter clockwise? I heard they are locktighted in. Did you have to use a heat gun to break them free? Did you have to head space the replacement 10.5" barrel and if so where did you get the headspace gages? Any other advice you can offer would be greatly appreciated.

I can bump my little VZ61 Scorpion SBR on demand from the shoulder at about 500rpm, I would guess. I am determined to learn to do it with my 27A1. Just wondering if anyone has tips on the best way to do it. I will start with the technique I use with the VZ61.

If you modify the mag catch will Kahr mags still work? If they wont then why would I not want to modify surpluss GI mags so I can use both? I have no intention of selling my semi 27 which I just sent a Form1 in to SBR it and I certainly cant afford a FA read deal 28.

I just picked up a used AO 1927A1 and will send in my paperwork to SBR it soon. I have a VZ61 Scorpion SBR that bump fires from the shoulder like crazy. Figured I might as well use the Tommy Gun the way it was designed. Just wanted to know if anyone has mastered bump firing one from the shoulder?