I do not know the answer to your question. However, I was told that most likely you wouldn't see immediate damage from this kind of thing, giving you a false sense of security. Put more than one through and you could be making the parts weaker faster.

But dont take my word for it.

 

My advice is that if you need more than a 3" mag shell to go out and buy a 10 gauge. Also one way NOT to mistake a 3" for a 3.5" shell would be to empty your shells into a jacket pocket and load from there. this would be very much like using a shooting vest. Plus Federal Black cloud is about the best there is at a decent price.

 

I know for sure that the gun will not cycle the shell and jam up pretty bad, but I'm pretty sure doing it once would not cause damage to the gun.

 

Will a 3 1/2" shell fit in a 3" chamber & the bolt close?

BOB

 

My advice- put 'em in your pocket like someone said earlier, and buy a different color shell than the other guys have.

 

If you are that concern about making a mistake get the 3 1/2 gun. This way you can shoot 3" shell and NEVER have to worry about putting in the wrong shell.

 

Has anyone here accidentally fired a 3.5 inch shell from a 3 inch chambered shotgun? What was the result?
The reason I ask is I am in the market for a new autoloader and I can get a nice Urika 2 for a lot less than a 3.5 inch gun. I shoot 3 inch for ducks but some of the guys I hunt with insist on 3.5s. I'm worried that in the heat of the moment when I'm reloading in the blind I might grab a 3.5 by accident.

If you are that concern about making a mistake get the 3 1/2 gun. This way you can shoot 3" shell and NEVER have to worry about putting in the wrong shell.

+1

 

I have mistakenly fired a 3" shell in a 2 3/4" chamber with no ill effects but not the 3.5.

 

If you are that concern about making a mistake get the 3 1/2 gun. This way you can shoot 3" shell and NEVER have to worry about putting in the wrong shell.

I agree too. There's nothing as versatile in the waterfowl blind than a 3 1/2" 12 gauge model.

A couple of things though. I'm not sure if a 3 1/2" shell will feed into the magazine of an AL391. It may also not be able to feed directly into the chamber thru the ejection port. I'll check one of my buddies when I get a chance or maybe someone else will beat me to it. I tried getting a 3 1/2" shell into a few of my non 3 1/2" guns. The Franchi 612 (3")would go thru the port but not into the magazine. The Franchi AL48 (2 3/4") would not go thru the port but would go into the magazine. They both were tight fits.

The shell it's self has a different feel and lok to it. The 3" is about as long as my thumb with the 3 1/2" being longer. If you are using you own shells, keep then close to you. You could also mark them or get a shell that is a different color than what everyone else uses.

 

I know for sure that the gun will not cycle the shell and jam up pretty bad, but I'm pretty sure doing it once would not cause damage to the gun.

Ditto that .
At least in a 3" Benelli .
I was using 3.5" while goose hunting a few years back and my buddy mistakenly grabbed one from my box and stuffed it in his Benelli .
Not sure but I think it was an M2 .
Jammed up big time .

 

I'm not about to argue the bemefits of a 3.5 inch shell in a duck blind. There are somebenefits with very large shot in order to keep the pellet count up, but no more. However, in answer to your original wuestion about giring a 3.5 inch shell in a 3 inch chambered gun, DON'T DO IT. Tom Roster, in a recent article in Shooting Sprotsman Magazine has gone on record stating that an over sized shell in a short chamber will raise the pressure about 150 psi per 1/8 inch length increase, so using this formula it would raise the pressure 600 psi. The problem with this comparison is that it needs to be qualified. The SAAMI allowable pressure for a 12ga 3.5 inch shell is 14,00psi. The max allowable pressure in a 12ga EXCEPT the 3.5 inch shell is 11,500psi. Theoretically, you are starting out with a 2.500psi OVER PRESSURE before you enven factor in Roster's arbitrary 600 psi.

Sticking a 3.5 inch shell into a 3 inch gun is bad medicine.

Frank

 

I don't know from first hand experience, but I'd presume that an auto with a 3" chamber would not eject a 3.5" shell as the chamber is only 3" and the bolt would not have enough excursion to travel back far enough to eject the shell. I think you'd notice a problem right away.

 

All I can say is, If you think you might do it, and you do it, you might be lucky and suffer nothing worse than a bulged barrell. or God forebid! and the gun blows up! Maybe hurting or killing your buddies in the blind,listen to the advice given above.

 

Will a 3 1/2" shell fit in a 3" chamber & the bolt close?

BOB

Generally, yes. Shell sizes are unfolded lengths, not unfired lengths.

 

I realize that this is now a pretty old thread, but I wanted to thank everyone for there advice. I ended up buying a Browning Silver with a 3.5 inch chamber. I may not ever (intentionally or otherwise) fire a 3.5 inch shell, but I'll have one less thing to worry about. Again, thanks to everyone who responded!

Cheers,
Matt