Some Questions on SBR'ing my 1927A1

[MadDogDan]

My Stamp finally came in the mail (6 months mailbox to mailbox) to SBR my Kahr 1927A1. I purchased a new 10.5" barrel and ring sight from "Thompson Barrels" that is made to original Colt specs and am ready to do the barrel swap. My big question is when installing the new barrel do you guys use some sort of thread locker on the threads? Something like rockset, red locktite, blue locktite, etc? Second Question: How do you hold the ring sight in place while drilling for the cross pin? I was thinking of mounting the barrel, test firing to make sure everything works perfectly, then using stud and bearing mount (green locktite) on the front ring sight to hold it in place. Once the bearing mount sets up I would then drill for the cross pin. That way the ring sight would not move while drilling. I decided on using the ring sight instead of the Cutts Compensator as I hate that look. My TommyGun will look like a 1921 model.

 

What do ya'll think???

Edited September 7, 2016 by MadDogDan

[MisterB]

I'm torn with this too, because I'll be making my M1 an SBR. I like to do things myself, but the problem with this is that from what I've read, it isn't as simple as you're thinking. Apparently just getting the old barrel off is damn near impossible without specialized equipment you probably don't have.

[anjong-ni]

Hey Dan,

You might purchase the new ringsight from A-O. It's made for the semi-Thompson, taller than the USGI version so you'll be right on target. These are polished blue, undrilled, and are very nice. They press gently onto the barrel taper, tight enough that they don't really need the pin. Undrilled, it gives them a sharp, streamlined look you might like.....Phil

http://www.auto-ordnance.com/Firearm-Parts/Thompson-M1SB-28-Front-Sight-M1-28-TM1.asp

[james m]

I ended up using Doug Richardson's barrel vise to do mine and it was a chore since his vise is designed for the military models. Installing he new barrel was no big deal and I didn't use any Locktite which apparently had been used on the original 16" barrel. I never cross pinned the Cutts and to date I've not had a problem.

Jim

[brassmagnet]

I don't think loctite is necessary for the barrel as long as you torque it in good and tight. The front sight - yes - you have the right idea there - that's what I would do. I went with a CC on mine, but I do have a front sight waiting to be changed out when I get the urge to have the "Sgt. Saunders Combat look".

[anticus]

With the "quick change" barrel option you can have it both ways.

[MisterB]

With the "quick change" barrel option you can have it both ways.

How does that work?

[anticus]

There is more than one setup, but the one PK did for me uses an Allen key threaded through the base of the grip mount to secure the barrel and a witness mark to index it.

I have one barrel with a comp and one with a ring sight and can swap one for the other in less than a minute. Slick.

[MadDogDan]

There is more than one setup, but the one PK did for me uses an Allen key threaded through the base of the grip mount to secure the barrel and a witness mark to index it.

I have one barrel with a comp and one with a ring sight and can swap one for the other in less than a minute. Slick.

 

I got the old barrel off and will mount up the new 10.5" this weekend. I checked the fin diameter and the 1927 barrel is not made to original specs. The fins on my 10.5" (Colt specifications) barrel are smaller in diameter. I am thinking of having my now, spare 16" barrel turned down to the proper profile and having it cut down to 8.5" and the Cutts Compensator permanently attached so that it is 10.5" OAL. One of the reason I do not like the CC even on a proper 10.5" barrel is that it makes it look too long. This might be a cool alternative. Then I can switch them when I feel like it.

[Hang-Fire]

I used blue loctite on my new barrel when I installed it. The original front sight was a tight friction fit on the new muzzle. I took it to the range and was able to tap the sight to get the windage right. I then loctited the front sight in place. Once it had set up I used the original pin hole in the front sight to drill the new pin hole using my drill press. I've been very happy with mine.