Win Mod12 Trench Gun Conversion

[rcathey]

I’ve been using a laser cutting service for some projects at work recently.
If you could get a CAD file drawn up using the stub of the heat shield you have, you could at least get a quote for having a flat cut.
You’d need to find a way to bend it round though.

I could do the CAD file for you but I’d need the heat shield in hand.

Anyway, the cutting service is Online Laser and CNC cutting for metals and plastics - Instant Quotes

[baltimoreed]

If there is 20 inches of barrel I would cut it there and install a mount. Also I don’t think the pump handle is correct for a riot gun. Go on over to the machinegunboards forum and scroll down to the shotgun subforum. There are some sg experts over there too.

[Madcap]

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

Had me cornfused there. OK, so original M12 Trench doesn't taper toward the end of the barrel. With this gun and Riot conversions the barrel does taper so it would requiring a sleeve if an original adapter is used.
Excellent - thank you!

[browningautorifle]

Go on over to the machinegunboards forum and scroll down to the shotgun subforum. There are some sg experts over there.

You had Tom Doniphon here, there are none better. He told you what was what.

[Madcap]

I’ve been using a laser cutting service for some projects at work recently.
If you could get a CAD file drawn up using the stub of the heat shield you have, you could at least get a quote for having a flat cut.
You’d need to find a way to bend it round though.

I could do the CAD file for you but I’d need the heat shield in hand.

Anyway, the cutting service is Online Laser and CNC cutting for metals and plastics - Instant Quotes

That sounds very encouraging. I don't have a way I know of to manage doing a CAD file though.... I'm pretty low tech and not too smart in that area. I could send the stub I guess if you think you could make a compete pattern but I don't understand how a full length pattern could be made from the incomplete, short stub to include the wider, flared rear portion. If I make myself clear....but Let me know what you think, I appreciate it.

[Madcap]

Attachment 123768
If there is 20 inches of barrel I would cut it there and install a mount. Also I don’t think the pump handle is correct for a riot gun. Go on over to the machinegunboards forum and scroll down to the shotgun subforum. There are some sg experts over there.

The barrel has enough to cut it. It would need to be cut at 20-1/2" according to East Taylor. Actually my Riot Gun barrel is 20-5/8" exactly. At any rate if I decide cut it'll have enough. Also you're correct - the slide would need replacing. The one that's on it has some nice grain but not at all the right one. This is such a sweet old gun - and probably cherished for many years. It shows excellent care and I actually have some hesitation to modify it, but if I do, hopefully I'd like to do it right.
Best -

[rcathey]

how a full length pattern could be made from the incomplete, short stub to include the wider, flared rear portion.

I think I could get that detail from scaling off pictures on the internet.
When I get back to the office tomorrow I’ll do a mock sketch to get an idea on price.
Just the approximate amount of holes, length, etc. That would at least tell us if it’s worth proceeding with a real drawing

If you could tell me the metal thickness and the diameter of the holes, that would be enough to start.

[Surpmil]

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

Your instincts are good IMHO. If you want a functional gun what is gained from adding the bayonet mount anyway? Not that a bayonet isn't a useful appliance, if only psychologically, but I'd look for one like mine which has already had the Coutts cut off.

[Madcap]

I think I could get that detail from scaling off pictures on the internet.
When I get back to the office tomorrow I’ll do a mock sketch to get an idea on price.
Just the approximate amount of holes, length, etc. That would at least tell us if it’s worth proceeding with a real drawing

If you could tell me the metal thickness and the diameter of the holes, that would be enough to start.

That's very considerate. I have to be away this afternoon but will try to measure the metal thickness and diameter of the holes ASAP.

[Madcap]

Your instincts are good IMHO. If you want a functional gun what is gained from adding the bayonet mount anyway? Not that a bayonet isn't a useful appliance, if only psychologically, but I'd look for one like mine which has already had the Coutts cut off.

Based on what information is available it appears the compensator was a personal add on. That being the case it helps to justify cutting the barrel on the other hand I haven't convinced myself it the best thing to do to this fine old gun. I've been looking for another donor with a "CYL" bore but so far nothing has come up that's in good condition for a reasonable price.
Interesting enough I did find what appears to be a completely original, excellent condition, early M97 WWII Trench Gun - price is $1700. I'm selling another shotgun today and if I sold the current donor it might be a tempting alternative - if it lasts long enough.

A Trench Gun bayonet mount isn't a practical accessory as much as the attraction to the weapon's unique presence and military significance.