42 replies to this topic

[awp101]

Ah, now I see (no pun intended...).

Thanks!

[REISINGSTAR]

One more vote for the manufacture of new frames!i would buy one as a semi-owner.Now,if I could just get my sight to stay on!

[Zamm]

Reisingstar,
Send that puppy to PK for his most excellent sight riviting treatment.
Never a problem again!
Zamm

[Sgt]

I know it is probably an economic issue, but I would want the hold open feature in the selector hole, as some have done with their modified frames. Maintaining that authentic look would be a priority feature and I would certainly be willing to pay the extra bucks for it. Having said that, it would be a difficult decision. The added .1" would go a long way toward tilting the scales in favor, even without the simulated selector hole.

Little off the subject, I know Dave has been working on spring & buffer modifications, for easier pulling of the bolt. I think that is a major need to make the Kahr transformation complete. No pressure intended, but I wonder if anyone has heard anymore about that project.

[PK.]

I would like to divide this into two sections.

First, the desire to use the ’28 SMG detachable stock has been #1 on the semi auto owners wish list since these guns were introduced; and rightly so. Attempts to accomplish this have ranged from the ungainly NAC adapter (offered soon after the guns) to some very nicely done alterations that come very close to the real ’28 SMG frame (I did my first one in ’76). While a nice conversion can actually be accomplished for less money, there is definitely a market for an “off the shelf” product, and such would be welcomed.

The second change being discussed is not so simple. It should be noted that the infamous .10” that separates the FA and SA guns was taken from the square, rearward part of the receiver and bolt, not the frame. The front part of the receiver that accepts the round “stem” of the bolt remained unchanged. The SA frame is basically the same as the FA part (with small modifications). This allowed the use of modified surplus FA parts in the early design (did you know the first SA sears were made by cutting a notch into FA sear levers?). The intent of the .10” change was to preclude a FA bolt being used in the SA receiver.

Because the top plane of the frame is the lower surface upon which the square part of the bolt rides, the relationship of the fire control components contained in the frame to this surface is important. As the receiver was shortened, the fire control components and frame (in effect) rose of necessity, taking with them the magazine catch. This necessitated the use of modified box magazines or a modification of the mag catch because the top of the box magazine stops against the receiver. It had no effect on drums as the drum slots that position the feed lips in relation to the bolt stem are cut into the receiver and were not moved. The lateral clearance slots in the frame for the drum mag catch protrusions were lowered, however.

Some thoughts on lowering the frame to compensate for the magazine catch position: The portion of the frame that contains the fire control parts can not be changed, as these parts would not then be able to interface with the sear, or bolt. The only part that could be functionally lowered would be the magazine catch. The shape of the magazine catch is such that it shadows the trigger guard cutout on the left side. If the catch is lowered on it’s own, it will intrude into the trigger guard .10”. If the trigger guard cut out is lowered in order to compensate, the top .10” of the trigger will be buried in the frame. Neither option would seem to offer much in the way of improved esthetics, and having .10” less trigger to pull seems awkward too.

All this assumes that a stock SMG magazine catch is to be used on the new frame, without modification. I am not sure what the answer to this problem may be, if there is one. It would appear to me that some compromise is still needed, and I am not convinced that there is anything better than simply lowering the engaging pin on the magazine catch, as has been done for years.

The above is simply the ramblings of an old man on a spring day. I wish Damon all success.

[Motorcar]

I for one, have learned more from your "ramblings" old man in the past year than I could have imagined. We are all indebted to you one way or another. Keep up the good work!

[LIONHART]

Oh come on PK, a little competition will be good for yeah!

[Bisley45]

I'm with PK on this, do not muck with the mag catch hole location, let people buy or modify the mag catch to take FA mags or use their existing SA mags. Otherwise we have a third and propretary lock work $more money$ and I'll bet most owners have either gone one way or another on the magazine mod.

DO add the rocker piviot hole, wether it's marked lock/unlock, Automatic/Semi Automatic, Full Auto/Single, or best yet offer all three variations with the parts needed to make it work so we can either put the %#^&*@! third hand in a drawer as a future colectable or put the third hand in its propper place (the trash can).

Can we pre order yet?

BB

Bisley45@hotmail.com

[LIONHART]

Bisely, there is no problem with the Magazine Catch. Nor, will any modifications be needed to any '21/28 Catch to install in this Frame. And as mentioned above, this Trigger Housing will hang one tenth lower. Simply put, NO MODIFICATIONS WILL BE NEEDED TO THE MAGAZINE CATCH for this frame to accept UNMODIFIED TSMG MAGAZINES. The design of this Frame has all been worked out. It will be a great success! Yes, a Bolt Lock feature will be available as an option for those folks who want one.

[Bisley45]

I seriously doubt things would look right with everything moved .1000" what about the people with SA TSMG mags, then they couldn't use them. Damon already offers modified mag catches. It seems to me MUCH more sensable to keep everything identical, that way if you have a large stock of modifed SA mags you can buy the frame and use the unmodifed catch, or buy the modified catch seperate or as part of a package deal.

how could you move everything .1000" of an inch, if you moved all the holes down the sear and disconector would have to be built up to engage the bolt. I could see moving the magazine catch down .1000" so an unmodified GI catch could be used but that would block off some of the space in the trigger guard. I find that a bad idea, so would anyone else with normal or large fingers. I'm not mutton handed but I like space around the trigger so I can wear gloves and not get my fingers bound or pinched.

BB

Bisley45@hotmail.com

[LIONHART]

Bisely, I don't follow you. Indeed, many people modify the Magazine Catch to use unmodified Mags. This new Trigger Housing solves many problems, without creating new ones. For those who have Magazines that were modified for the stock '27 Frame, those could be fixed if their owners wanted them fixed. The appearance of the Frame will be very nice. Bisely, just hang on, you shall see the finished product.

Edited by LIONHART, 31 March 2004 - 11:56 AM.

[Z3BigDaddy]

Take pre-orders then decide... How many would you have to produce to get this price? I'm converting to f/a on mine, and if I don't have to buy a whole 999 buck gun to butcher, that would be fine by me....

[Bisley45]

Lionheart


"6) What do I mean by "Hang Lower"? Simple. When WH designed the Semi-Auto Thomspon, the Receivers were reduced in height by one-tenth inch. They did this to eliminate persons from installing FA Bolts, ect. By doing this, the Trigger Housings (Frames) mounts one-tenth higher on the SA Receivers. This has caused Drum fitting problems, and Magazines must be modified in order to compensate for the height reduction. NOW, Damons' Frames will be made to hang one-tenth inch lower. This will solve the problems of fitting Drums/Magazines, plus creating that proper Thompson SMG look that were all fond of. The original one-tenth height reduction on the SA Receivers are quite noticable. If one has a '27 next to an original '21/28 one could easily tell a big difference. With these new Frames, the original look of the TSMG Receiver/Frame for YOUR '27 will be intact. Even using a modified '28 Frame one still has to modify Magazines, or modify the Magazine Catch since there still is a height problem."

I'm not following you. I know the recever is .1000" shorter, how are you going to make that up with a trigger frame without moving the pin holes. I don't get how you can move the whole thing as you have to keep the sear in contact with the bolt. If you move the mag catch location down .1000" you can use an unmodifed magazine catch but if you move the rest of the holes down you have a .1000" gap between the leg of the firing pin and the sear and the disconector. Maybe you need to draw me a picture. How can you make the outside hang lower and not screw up the interworking geometry /or/ have the trigger stuck .1000" higher in it's opening.

I loved the idea until the .1000" was mentioned and using the unmodifed mag catch. Then I got LOST and BEFUDDLED.

BB

Bisley45@hotmail.com

[LIONHART]

Bisley, your just going to have to wait! NO information will be provided on the specific working details of the new Trigger Housings at this time.

Edited by LIONHART, 31 March 2004 - 01:17 PM.

[Bisley45]

OK, I'll wait hopefully not too long. sent you a couple of E-mails. still lost and befuddled how you can make up that .1000" without changing hole locations or making new internal parts.

BB

[M1tommygun]

If I had the 1927 model I most definitely would like to have a lower frame that matched the gun. Since I have the M1 version it is not a problem. If you manufacture them I believe they will sell. One thing I was wondering about, if the new frame would allow the removable stock would it fall under the idiotic AWB's ban on that type of collapsible / removable stock, or am I just thinking too much? I have seen the nonsence about the pre-ban / post-ban receiver manufacture time. I did not know if it fell under the same or similar category.

Scott

[Sgt]

This issue was raised before. In Doug Richardson's Semi Thompson book, he prints an ATF letter that states detachable stocks are not classed as folding or collapsible stocks. When I filled out the SBR application for my Khar, I wrote the words, "detachable stock," as part of the description. it was approved without a hitch. For these two reasons, I personally feel confident that this is not an AWB concern.

[SecondAmend]

Just wondering:

When a detachable stock is detached from a standard 16 1/2" barrel 27A1 does the overall firearm length become less than 26"?

If so, I think I could own the gun but I would have to register the gun as a pistol according to my local rules.

Thanks to those who know.

The straight-forward frame swap does seem like a simple, clean way to provide a more portable and realistic product.

[Bisley45]

When I measured it was 31" from the tip on the back end to the front of the Cutts on my WH. Maybe that is why the BATF can't throw a fit about detachable butstocks on the SA thompsons.

BB

[PATHFINDER]

How about this: You do not move all of the holes. You just make a differnt length mag release with the hole in front of the frame located .100 lower. Still arches over the trigger housing the same way it just contines down a little farther and you can leave the notch for the drums in the same spot. OR you can look at it like this: if you cut the trigger group in half longitudinalyin the front cut just above the hole for the mag release. in the back half cut in between the trigger guard opening and the fire control holes. Add you .100 inch in along these lines. Viola! Fire control stays where it should and the mag release move .100 away from the reciever. You can use ummodified mags and the gun looks over all 'taller'. Only problem see is the trigger will be .100 farther up in the guard. Or you make new triggers but this will increase the radius of the triger arc and inclease lenghth of trigger pull. If this doen;t make any sense email and I will send you a photo of what I am talking about