Win Mod12 Trench Gun Conversion

[Madcap]

I posted a previous thread about converting my original WWII Model 97 Riot to Trench Gun but decided against it in order to conserve it's original history. Since then I acquired an E series Model 12 mfd 1946 with original "CYL" bore that could make an ideal candidate for a conversion but unfortunately it has a Cutts Compensator. Not only that but the gun is in much better original condition than expected which again gives me pause about modifying another nice old gun.

Another issue is finding a quality repro bayonet adapter that's been difficult. Photos are provided in order to encourage comment.

Not sure if the compensator is factory or added later.

Photos included to encourage for comment.

Thanks

edit: barrel measures 28" with compensator

Information

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[baltimoreed]

Built a M12 trench a few years ago. East Taylor makes a heat shield bayonet mount for the civilian sized barrel M12. There are a few other bits needed. Their heat shield needed a lot of extra work. After that I did a riot M12. I shoot them in Wild Bunch matches. That cutts on your donor will have to be cut off. Both of mine were not original. The trench donor was an old reblued gun while the riot donor had a cutts and a busted stock. Ones from 1925 and the other 1940. Slick shotguns. Good luck.

[Madcap]

Thank you for the reply. I'm really undecided as to cutting this gun any time soon. No doubt it would make a great donor considering, but it's been an obviously well cherished old firearm and it's difficult to justify destroying it's historical originality. I'm not sure if the compensator is factory or after market which might influence the decision. The fact I can't find an adapter yet also puts a hold on any mods.

I have an original "W" marked bayonet adapter but hand guard is unusable except as a possible pattern early 4 row. If I find a hand guard or machinist to make one that would be a big step. Come to think of it the 4 row hand guard was earlier and probably not correct for the later WWII M12 or early post war.

[browningautorifle]

Not sure if the compensator is factory or added later.

The blue is very nice for 1946, maybe reblued? The barrel should be a 20"? Then measure the Cutts and see if it's the extra 8" by itself. I expect someone took a riot and added a Cutts. You still have to locate a heatshield. That might be harder than you expect.

[Madcap]

Attachment 123748

The blue is very nicefor 1946, maybe reblued? The barrel should be a 20"? Then measure the Cutts and see if it's the extra 8" by itself. I expect someone took a riot and added a Cutts. You still have to locate a heatshield. That might be harder than you expect.

I looked at the surface pretty close and it doesn't appear refinished - markings still look pretty crisp to me; barrel measures 21-3/4" + compensator 6-1/8"= 28-7/8" total. The thought did occur it might have been an original riot considering the "CYL" barrel and date of mfr but existing barrel length doesn't match.
Anyway, maybe some photos might shed some light.

Your input and help is so very much appreciated...thanks all.

edit: any decision to go ahead with a modification really hinges on the adapter no matter what - then proper cutting grooves under the barrel - also just realized the mag tube is longer than my orig mil US M97 riot and may need to be cut also.

[Tom Doniphon]

The Cutts was added later. The barrels on Model 12s with factory installed Cutts do not have choke markings.

[Madcap]

The Cutts was added later. The barrels on Model 12s with factory installed Cutts do not have choke markings.

Yes sir, I remember reading that somewhere as well which does influence the decision on modifying the gun somewhat - thanks

I'll check back in later -

[Tom Doniphon]

If you use a Winchester USGI bayonet adaptor rather than an aftermarket one you will most likely have to use shims to have it fit properly because Model 12 riot barrels taper towards the muzzle whereas Model 12 trench gun barrels do not. When the military converted Model 12 riot and long barrel shotguns to trench guns they used a sleeve on the muzzle end of the barrel to make the adaptor fit properly. The sleeve had the 3 transverse grooves cut into it to accept the adaptor.

[Madcap]

If you use a Winchester USGI bayonet adaptor rather than an aftermarket one you will most likely have to use shims to have it fit properly because Model 12 riot barrels taper towards the muzzle whereas Model 12 trench gun barrels do not. When the military converted Model 12 riot and long barrel shotguns to trench guns they used a sleeve on the muzzle end of the barrel to make the adaptor fit properly. The sleeve had the 3 transverse grooves cut into it to accept the adaptor.

Thanks Tom, I remember reading something about that. There's much to learn and I'm trying. However - now what is confusing is the barrel on this 12 isn't straight but tapered leading toward the barrel (?) or would that be normal for a "CYL" bore?

[Tom Doniphon]

It should be tapered (narrower towards the muzzle end). Only the Model 12 trench gun barrels have no taper.