Help with 590A1 failure to fire

[Rokchukrslave]

My 590A1 has been giving me problems lately and I can't figure it out.

Half the time I will get failures to fire.

It either goes boom or there is no primer strike at all, no light primer strikes.

I can clearly hear and feel the hammer fall on the no strikes.

Sometimes I can get it to fire the second time, sometimes not.

I have detail cleaned the whole gun.   No difference.

I have removed the firing pin and see no damage.   It or it's channel were not dirty enough to cause problems.

I can't see any excessive wear or damage anywhere on the shotgun.   Everything seems to be working properly.

Mag tube is tight and so is the cap and barrel.

 

Thanks for any help.

ETA:   I just thought of something.   Could the bolt locking pin be broken and I just can't see it?

Edited July 6, 2017 by Rokchukrslave
more info

[GunCat]

Check the action tube nut that holds the forearm on the action tube. If the nut has backed off and allowed the forearm to move forward the action may not be completely closing / going into battery.

[Rokchukrslave]

I think I might have this figured out.   The 590A1 hammer has a half-cocked position that I believe is part of it's military drop safe requirement.  

I have researched and found that a weak mainspring can cause the hammer to catch on the half-cock position so this makes total sense with the no strikes.

I have several thousand rounds through this shotty so I can see a spring wearing out.  

The great news is it's a $6 part.

I'll report back when I can wring it out so a future searcher won't have such a hard time finding this info.

[Rokchukrslave]

It was not the spring, bummer.   After learning more than I ever wanted to know about the 500/590's I have ruled out anything  within the trigger group.

I believe my problem is excessive headspace.   The only significant wear I have is on the locking lug of the bolt lock.   Everything else looks fine.

A new complete bolt w/slide was only $40 off E-bay so I'm giving that a try.