doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com Gun doesn't like Fiocchi?

I was shooting clays yesterday with a superposed. It opens hard after firing Fiocchi shells. It works just fine with Remington shells (new or reloads). What is going on? Do I need to polish the chambers?

More likely it is the primers in the Fiocchi(s). Some primers crater a bit and cause the firing pins to drag and hang in them when opening the gun.

Just use shells that don't do this, like the Remingtons. You can probably find more about this by doing a search on kere.

''kere''???

You know what it meant, a simple mistake and you want to nit pick.

i had extraction problems with Fiocchi shells in my tube sets. I felt it was the cases rather than the primers!

You might check if the firing pin return spring (lower barrel only) is present and functional.

Sounds like either the firing pin(s) are dragging or maybe the case head is swelling. I'm inclined to think it is the first, either because the primers are cratering as mentioned above or the firing pins aren't retracting. Polishing the chambers isn't likely to make things better.

I've probably fired 4 or 5 cases of Fiocchis over the past year with no problems that I remember. I've had similar problems with Federal Top Gun in the past.

Maybe try swapping a box of Fiocchi with another shooter for a different brand to see if it happens in their gun or not.

Put a little grease on the sides of the case heads
Report back please

The copper washed steel heads expand but do not shrink

I've been searching for a Browing engineering drawing for confirmation without success but will share this.
We know (certainly pre-WWII) Superposed typically had a 1/2" forcing cone to a bore of 18.4 mm = .724"
It has been stated that the chamber dimensions were slightly undersized. U.S. makers typically bored chambers .810 - .812" tapered to .796 - .798"
Do you have a micrometer?
I think Hal, Chantry & skeettx are correct that the expanding steel case heads are the issue.

The chambers are slightly smaller than my newer superposeds. The Fiocchi's work fine in the newer superposeds. Grease sort of helps.