My normally reliable 1947 12 gauge started malfunctioning. Extraction was good but the shells weren’t always ejecting. I thought maybe the Fiocchi ammo was at fault, but it was jamming with Federal shells as well. Here’s an old picture: I’d had problems with extractors, but I couldn’t see an ejector wearing out. Last week I noticed that I could see more of the barrel extension than usual. That seems strange, normally a worn forearm will position the barrel too far forward. I couldn’t understand what could move it the opposite direction. Still, swapping firearms fixed the problem.
When I got home I found a crack in the forearm. I never would have guessed that a cracked forearm would cause such a malfunction.
Yep, that sucks, I always check that magazine cap out of habit, as I'm sure you do, at every station. More than one time it has come lose.
Well, that’s the point. The cap wasn’t loose. A loose cap would have positioned the barrel too far forward.
Ok I think we both mis-understood, I never assumed it was lose, but I did miss that it was to far to the rear. So what do you think caused it to crack?
Couple of thoughts... -Is it possible an old well used spring, upon recoil compression could overtime expand into a slight larger diameter or "oval" in the back to middle operating areas? Causing stress on the wood? But of course 76 Years a bunch of years! -Ever seen a wore out spring jump over the ring in the back shooting light loads?
No, haven't seen it, just trouble shooting through thought. I have seen a number of really abused Auto 5's over the years... they still work but they looked like they've seen combat with Russian forces on the Eastern Front.
The root cause was the 2” crack at the rear of the forearm, allowing it to sit too far aft. With the barrel extension blocking just 1 millimeter of the ejection port, the gun jammed. Look at the pictures. Note: the sharp eyed will see that those are two different guns. But the ‘47 looked the same when the forearms were swapped. In the field, my quick fix was to loosen the magazine cap a half turn.
Ok got it. Had only glanced over pictures initially. Does it look able to repair forearm with pins and reinforce or too far gone ? 2" sounds a sizeable crevas going on.
I’m going to glue it with Acraglas, eventually. This crack was previously repaired with superglue. It lasted a few years but I keep hearing wonderful things about the other product. I don’t think there’s enough meat there to pin it. It would have to be a very thin dowel. It’s funny, this crack occurred years ago when I first bought this gun. I’d bought a new “aftermarket” recoil spring from Brownell’s that was too big, causing the crack. I left a nasty review — and they sent me a brand new forearm! That part was a spare, but now it’s shared between two guns with damaged front ends.
"I’d bought a new “aftermarket” recoil spring from Brownell’s that was too big, causing the crack." W O W
