Antonio Zoli O/U action jams

[Oneeyejd]

When shooting the UPPER barrel, the action "Jams" and is difficult to open. Lever lock is fine, smooth; the fired shell shows "some" small firing pin drag marks in primer. Have polished firing pins, etc and they are smooth and free. Action does NOT jam when snapping on empty chamber; either upper or lower or both barrels. Hammer springs are "strong" (leaf type, not coil).
Any Suggestions on what to try next ????

Thanks,
Oneeye.

 

[4v50 Gary]

Check headspace

 

[DM~]

You didn't say anything about the cartridge/ammo, I'm betting it's at the MAX for THAT chamber... (read slightly sticky chamber)

I've seen the same thing happen in other O/U's, top bbl. always meets MAX pressure first...

DM

 

[RPRNY]

In the event that you were unaware, one should not dry fire shotguns on an empty chamber. If you have done so a number of times, you may have damaged your firing pins or the pin bushings, perhaps rendering them slightly long. If combined with slightly wonky brass on a batch of shells or reloads, you might get the condition you describe.

 

[jaguarxk120]

Weak firing pin return springs.

 

[earplug]

Check the ejector mechanism.

 

[Oneeyejd]

Gents: Thanks for inputs! For brevity, I did not go into the "other things" but to get a good history oF problem, here goes. (all parts mentioned have been stoned and polished and entire assembly Dynkim checked for rubs/clearances)
Ejector is slick and smooth; Firing pins tips is round and smooth, body polished; Length to factory spec and protrusion beyond face to .040; Firing pin return springs tested with stronger springs.; Headspace in specs.; Shells (all factory-- tried with no chg in results)--Federal, AA, Remington, Rios, Winchester all in 1 1/8 oz target loads.
Would like to try "lightening" hammer springs (leaf type) but NO Spare parts available----Would appreciate any sources !
All work has "Improved" the condition, but still binds up some. Zoli USA headquarters in San Antonio, Tx do not work on guns or stock any parts for guns older than 10 years and they do Not have any technical people on staff.
That's "the rest of the story...."
THANKS,

 

[DM~]

MY answer assumed it was a rifle, not a shotgun... Wish you had cleared that up earlier.

I've seen your problem with O/U shotguns that don't have rebounding firing pins, does yours have rebounding firing pins?

DM