out of battery?

[ksenter]

I have recently, through trade, acquired a Mossberg 500c 20ga w/ pistol grip. Upon firing it, if fired from one hand the action bar will reel back while recoiling, coming out of battery on its own. I'm fairly certain the shotgun should "lock up" and not be coming out of battery from the recoil alone. What controls "lock up" or am I mistaken thinking this is not normal? I totally stripped down the shotgun this morning and did a deep cleaning but have yet to reassemble.

Getting duracoated soon but wanna make sure there's no "big" issues before I get to that point.

 

[CviewGarand]

It's difficult to know without looking at it, but it's plausible that it's somewhat normal. The "LOCK UP" is accomplished by a mechanism on the trigger group. Upon firing, that piece moves down allowing the bolt to be cycled. First question is how far out of battery did it move?

 

[wildrider666]

It is normal. the amount of travel depends on the load and the resistance "Grip" and is amplified by your arm movement during recoil and your pushing against it. When a pump shotgun locks into battery, a lug on the bolt moves into a recess and locks in place. hitting the bolt release lets it come out. when you fire the shotgun the bolt release is also "released" but the back pressure on the bolt which holds the lug in the recess stays "locked" in place until pressure drops. then you manually cycle the action and go again. Semi-autos are similar but cycle from inertia or gas driven systems that allow the bolt lug to come out of the recess while still retaining enough gas pressure to cycle the action. This is why some low power shell will not cycle through a semi auto. This is why I have a H&K/Benelli M3 which can fire semi-auto OR pump action!

WR

 

[ksenter]

excellent. I had a thought that it could be normal, but wanted to make sure I have a "safe" firearm before doing anything else with it. Thanks for your replies gents.