Does anyone know what the pressures are for the different size flare guns? like the 12ga and 4ga/26.5mm? I'm thinking of picking up a German surplus flaregun and putting a pistol barrel of somekind on it. If it's all steel, then maybe it would be safe.?

Got to be very low. I took apart a 12 ga. flare once. It has virtually no powder in it. The propellent is packed into the bottom of the flare and acts like solid rocket fuel. That is what propels it up, not the powder charge.

FWIW, my flaregun is a (relatively) flimsy plastic and brass unit that couldn't hold much pressure at all, but it won't rust here on the coast and it works.

Don't know what it's like over there. Here (in Sweden) all flare cartridges that I've examined, old and new, have dual loads. The first one acts as a fuze that sets of the other "rocket charge". Some black powderish stuff seems to be the preferred powder.

So although I haven't got a clue to what the stipulated pressures might be, I agree with the previous poster that they are probably mild, despite the sometimes hefty recoil...



Still, in my mind I have been thinking along the same lines as you. Wouldn't it be neat with some kind of pistol barrel on one?



This design seems kind of sturdy, all steel and, it appears, a sturdy lock-up.



Pettson

I took apart a 30 (35?) mm flare once (type used on WWII aircraft) and found a very small charge of what appeared to be fine grained black powder. I am guessing it was no more than 5-10 grs.
C.G.B.

That looks like my WW1 German 4bore Flare gun. I've made some cases from turned down 20mm vulcan brass. Mine is made very heavy with 2 locking lugs under the barrel.

I haven't a clue as to the origins or age of the one pictured.

the only markings on it are Belgian Liege proof mark stuff. Where and when it might have been used I don't know.

It seems to be well made though. I'd say that overall fit, finish and appearance is very good for a piece like this.



Pettson