king of kings Posted June 29, 2015 Report Share Posted June 29, 2015 I am new so be gentle. I read a while back that you can modify a 1928 lower trigger to put on a 1927 upper assembly.Can anyone point me in the right direction or have a step by step guide?Thank you all for your time. Ryan Link to comment Share on other sites More sharing options...
shadycon Posted June 30, 2015 Report Share Posted June 30, 2015 Check with Doug Richardson, He has a thin book/pamphlet that explains all you need to know. " Thompson New Production Semi-autos". Link to comment Share on other sites More sharing options...
pjr2412 Posted June 30, 2015 Report Share Posted June 30, 2015 I believe he has been sold out of that booklet for awhile. Paul Link to comment Share on other sites More sharing options...
shadycon Posted June 30, 2015 Report Share Posted June 30, 2015 K of K; I can send you a copy if you would like. GK 1 Link to comment Share on other sites More sharing options...
lamellarllc Posted June 30, 2015 Report Share Posted June 30, 2015 I would like a copy as well if that's possible? Link to comment Share on other sites More sharing options...
king of kings Posted July 1, 2015 Author Report Share Posted July 1, 2015 K of K; I can send you a copy if you would like. GK Please that would great. How do I give you my info? Link to comment Share on other sites More sharing options...
shadycon Posted July 1, 2015 Report Share Posted July 1, 2015 Pm me e mail address and i'll send the info via attachement. Link to comment Share on other sites More sharing options...
anticus Posted July 1, 2015 Report Share Posted July 1, 2015 It's a shame Doug's semi-auto adaptor frames aren't available. Link to comment Share on other sites More sharing options...
deerslayer Posted July 30, 2015 Report Share Posted July 30, 2015 You have to mill or cut away the very front top edge where the semi receiver has the little step. Then also mill away a channel down the middle where the firing pin travels. A mill is suggested but a file or dremil tool have been used before. Then they will slide together. You will need washers inside to fill the gaps in the large full auto channel. Link to comment Share on other sites More sharing options...
Elbow Posted August 11, 2015 Report Share Posted August 11, 2015 Here a few pics Link to comment Share on other sites More sharing options...
Elbow Posted August 11, 2015 Report Share Posted August 11, 2015 It's a shame Doug's semi-auto adaptor frames aren't available. That would be something. Link to comment Share on other sites More sharing options...
anticus Posted August 12, 2015 Report Share Posted August 12, 2015 I know Doug is retiring (well-earned !). If someone takes over his business I hope they consider a run of the frames. With a large base of semi WH's and Kahrs out there I'd think a market exists for them. Link to comment Share on other sites More sharing options...
laurencen Posted August 12, 2015 Report Share Posted August 12, 2015 what is the reason behind putting a 28 lower on the semi? is it just to have a removable butt stock? Link to comment Share on other sites More sharing options...
emmagee1917 Posted August 12, 2015 Report Share Posted August 12, 2015 W what is the reason behind putting a 28 lower on the semi? is it just to have a removable butt stock? That could be one reason . Having the full auto selector switch there for looks would be a second reason . Changing the switch to function as a bolt hold open so you can switch drums without using a " third hand tool " or fighting it could be another . Also this would allow the use of unmodified USGI stick mags.Chris Link to comment Share on other sites More sharing options...
laurencen Posted August 12, 2015 Report Share Posted August 12, 2015 never thought of the drum and holding bolt open, Link to comment Share on other sites More sharing options...
anticus Posted August 12, 2015 Report Share Posted August 12, 2015 One of the main attractions of Doug's frame is the elimination of the .1" shortfall in receiver height that causes so many headaches with stick magazine lock up on the semi auto Tommies. It allows the use of an unaltered mag catch and mags and it improves the cosmetic appearance of the firearm. The downside is the cost of manufacture and the need for special custom internal parts to make it all work. I still want one. Or two. Link to comment Share on other sites More sharing options...
Elbow Posted August 13, 2015 Report Share Posted August 13, 2015 (edited) One of the main attractions of Doug's frame is the elimination of the .1" shortfall in receiver height that causes so many headaches with stick magazine lock up on the semi auto Tommies. It allows the use of an unaltered mag catch and mags and it improves the cosmetic appearance of the firearm. The downside is the cost of manufacture and the need for special custom internal parts to make it all work. I still want one. Or two.As I remember years ago Doug chimed in on what happened to the frames he once made. He said the ATF had a real shit fit about the frame because it was way to easy to convert to FA. So he had to destroy them. He did it by reverse enginering the SA frame that was unique to the SA design that the ATF approved of many years ago. So the basicly don't mess with a unique approved design by the ATF. What ever happened to the Polston Design. Is it still out and about or is it dead as a door nail. Edited August 13, 2015 by Elbow Link to comment Share on other sites More sharing options...
anticus Posted August 14, 2015 Report Share Posted August 14, 2015 Doug made a full auto frame for conversions (when you could still do that legally) and the SA frame. The full auto frame became verboten after the 86 law change. I don't recall any issues with legality on the SA frames, since the internal bolt cavity dimensions remained unchanged with the frame installed. The issue was the cost of making them and the need for custom parts. I haven't seen anything about the Polston efforts for some time. Probably DOA. Link to comment Share on other sites More sharing options...
lamellarllc Posted August 16, 2015 Report Share Posted August 16, 2015 Does anyone have a video of the full auto lower conversion using the modification to hold the bolt open I am rather curious on this looks? Link to comment Share on other sites More sharing options...
Joe H Posted August 16, 2015 Report Share Posted August 16, 2015 Don't know of any video but here is the bolt hold open: http://www.machinegunboards.com/forums/index.php?showtopic=5767&hl=selector joe Link to comment Share on other sites More sharing options...
lamellarllc Posted August 16, 2015 Report Share Posted August 16, 2015 That helps thanks you. Link to comment Share on other sites More sharing options...
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