extraction troubles on Mossberg shotgun

Vincent Phipson · Jan 31, 2018

Need help please.
I have a Maverick/Mossberg model 88 slide action shotgun in for repair. Owner complains of tight extraction. He has to tap the fired cases out from the muzzle with a cleaning rod. I have polished the chamber and it looks perfect. The extractor springs are good and strong. The 2 extractors have both got a good bite on the case rim. The pressure signs on the case head do not look excessive. It is still giving trouble. I have run out of ideas as to what to do next.

MilGunsmith · Jan 31, 2018

May be already done, but have you tried it with factory ammo? If he is using reloads, brass might not be resizes properly. Check chamber for out of round, it could have been slightly squashed.

FredC · Jan 31, 2018

I have seen other shotguns have extraction with the 1/2 length brass or steel on the hulls. I have a theory that the end of the metal opens up extra hard and makes an enlarged belly? in the middle of the chamber.
Not sure if I am right and no idea what the solution is if I am right.

Scottl · Jan 31, 2018

I was also going to suggest that it might have a "ringed" chamber, as in one that is slightly larger in diameter ahead of the rim opening. If that is the case I would suggest contacting Brownells for advice on what can be done.

Another possibility is the barrel may have been clamped in a vise without proper padding and the chamber is oval ahead of the breach.

Does a brand new unfired factory shell smoothly fall back out of the chamber if the barrel is tilted straight up? If unfired shells fall out and fired ones need to be driven out my guess is that you do indeed have one of the conditions described above.

gzig5 · Jan 31, 2018

We had a similar problem with an old Ted Williams branded shotgun my dad had. Using Federal ammo, you really had to yank on the forearm to get the case to extract, and sometimes it simply refused. With Remington or Winchester ammo it was perfect. It seemed to come on all at once because Federal worked in it previously, and I put it down to soft case heads or something on the Federal ammo. We simply stopped using federal and never had any more issues.
Moral of the story, try a couple different brands of shells.

jcmugavero · Jan 31, 2018

I second the ammo idea. Todays manufacturers dont use very heavy brass due to the new style hulls. I've also had a couple complaints of the same issue. Tried different ammo after verifying everything was to spec, and the issue dissapeared.

Anthony · Feb 12, 2018

I would have to agree on the ammo being at fault. I have seen the same issues with extraction as well as ammo that wouldn't chamber because of rim thickness being too thick. Problems were encountered with Remington brand on more than one occasion. I don't like to fix a firearm that isn't broke so always look to the ammo for discrepancies first.

72bwhite · Feb 12, 2018

defiantly look at the ammo used
I have a 1897 Winchester copy that will only extract
Winchester AA shells, the ones with aluminum bases one or 2 will
extract then it locks up.
those 97s are notorious for having crappy chambers.

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extraction troubles on Mossberg shotgun

Vincent Phipson

Aluminum

MilGunsmith

Stainless

FredC

Diamond

Scottl

Diamond

gzig5

Hot Rolled

jcmugavero

Plastic

Anthony

Aluminum

72bwhite

Titanium

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