Thread: Bolt forced open

Hi all, I was out shooting yesterday with some mates and one had a issue with the bolt of his 12g pumpy opening slightly after every shot, we believe the hand loaded loads might of been a bit hot because the recoil was quite hard. Theres no obvious damage to the internals of the shotgun. Any thoughts?

Pulling back on fore end while firing quite common with heavy loads , uconsoshly doing it .

Originally Posted by m101a1

Pulling back on fore end while firing quite common with heavy loads , uconsoshly doing it .

He was shooting off a sandbag rest with his forehand under the shotgun butt. So I wonder if it was the way gun was moving a the rest from the recoil. We've searched online but can't find anything about pump action bolt being forced open.

What sort of pump action? Some of them are almost designed that way. A little weight on the forearm and they come back like lightning.
Mossbergs don't but I think some of the Winchesters were

Could also be an issue with not quite properly locked due to dirt and gunk in the locking bolt rebate etc

Originally Posted by Three O'Three

He was shooting off a sandbag rest with his forehand under the shotgun butt. So I wonder if it was the way gun was moving a the rest from the recoil. We've searched online but can't find anything about pump action bolt being forced open.

Seems likely that if the bolt was opening from the chamber pressure then it would have been a much more exciting event youd be talking about.

This is theoretical - but it seems plausible that the rearward inertia of the bolt+foreend+sliding assembly might be enough to unlock the action as the shooters' shoulder, having absorbed the recoil, moves the shotgun forward again. Benelli added some extra sprung weight to the bolt and employed this effect to cycle the action automagically on their system.

they are supposed to do it.....thats why a good operator with a pump can fire as fast or faster than with a semiauto...BUT using really hot loads will stuff up your rythem.....the remington hypersonic steel loads are terrible in a pump,the only time in nearly 20 years that I have short shucked numerous times....

Try shooting it standing and see if the problem follows the operator or the load.

Shotguns are generally loaded to book-loads and not fettled...Why is it "quite hot"? Wrong chamber length?

As above, Pull the barrel and bolt. Check the locking recess(es) there should be a definite shoulder on the barrel and a bit of a ramp on the lug.

Had a mossberg many years ago that did that . Was a dirty locking tang that caused it not to lock properly .

Winchester pumps are designed to self-open after a shot is fired.

With other brands, shooting off a rest without holding the pump fore-end, it might open from inertia.

If it's opening while breech pressure is still high I'd expect the fired cases to show swelling /splitting of the base or plastic.

Originally Posted by csmiffy

What sort of pump action? Some of them are almost designed that way. A little weight on the forearm and they come back like lightning.
Mossbergs don't but I think some of the Winchesters were

i had the opposite yesterday useing 5 different loads to test out a 1300 winchester
a eley vip steel hi sppeed jammed it tighter than a catholic shielas privates.
ive had problems with turkish pumps opening before the shot
but all pumps release after the shot otherwise how would you recharge the chamber.
anyway upside im goin back to a remy 870 you can trust them anywhere anytime any ammo

remember the old ''ive gone back to brylcream ''
well'' ive gone back to remy'' a 870 black synthetic well used hunk of metal
you could beat wounded geese to death with when you run out of ammo
tommorow i fire 5 or 6 different steel and lead loads thru it and im not expecting any dramas.
even with ass kickin kent faststeel.

I had issues when first tried 3" shells..they were S&B and pump jammed.... a decent clean and a LIGHT oil of action and around chamber and no issues ever since..changing from an oil to breakfree clp made huge difference in wet conditions too.
but them hypersonics...semi only..and a good one starting with B or asking for trouble.

Originally Posted by gsp follower

remember the old ''ive gone back to brylcream ''
well'' ive gone back to remy'' a 870 black synthetic well used hunk of metal
you could beat wounded geese to death with when you run out of ammo
tommorow i fire 5 or 6 different steel and lead loads thru it and im not expecting any dramas.
even with ass kickin kent faststeel.

better the devil we know than the one we dont eh squire-id have lent you the trusty Escort had you asked...ducks for cover as air is filled with hi speed incoming verbals!!

Originally Posted by kotuku

better the devil we know than the one we dont eh squire-id have lent you the trusty Escort had you asked...ducks for cover as air is filled with hi speed incoming verbals!!

i havent had a escort since i won a tidy sum when rastes a 70 to one shot won the welly cup.
there re 3 days i dont remember saturday afyter 5pm sunday and the first half of monday.
oh you mean the turkish pipe cleaner and occasional boat anchor.
just got the 870 back from gunworks stock shortened hideous solid remmy pad discarded and a tasteful slip on jobby fitted all for around 100 buks.
beware mr canada the eides of october