There is a company called RM Equipment. They make the M203pi grenade launcher that is in use with the Irish / Saudis / Austrians / and Australians . They are located in Florida and after talking to him about selling the receivers ( as title 1 items ) i was able to convince him to do so providing that I rind a retailer that would take up his products. customers could go ahead and get a 37mm barrel or DD it with the NFA and have a 40mm barrel
The m203pi also has mounts for the Ak47/74, the ar15, the hk g3, and a few others and can be changed between weapons In just a few minutes as it has a quick detach setting. Pricing would be around the same as a LMT M203. I've tried to contact dealers to see if they will stock these and have talked to a site sponsor. Haven't heard anything back.  I'd love to see these hit the market.

The ONLY downside to having a 40mm tube would be that where are you going to find the projectiles ( the REAL ones ) to launch?

Oops. There are a few other obstacles to dispense with.

Price of each REAL deal.
Price of the $200 transfer tax for each REAL deal.
The paperwork and wait time to get the REAL deals approved.
A place to lob the REAL deals.
Keeping folks away who say "hold my beer and watch this".
I may not be aware of other things that would create a slight problem for ownership of the REAL deals.

It is entertaining to think of having one of those launchers on a rifle.

Now if you were just satisfied to having one on your rifle for cosmetics, to each their own I guess.

I'd be interested....depends on price though.

They would be sold as tital 1 firearms without barrels and could have a 37mm put on without a stamp . Or a 40mm barrel with a stamp . That allows 37mm owners to shoot tear gas , OC, smoke , flares and fireworks.

Price should be about the same as a lmt launcher but that is up to the site sponsor looking into this .

I have an LMT M203 (railed) and I'd buy another 40mm