View Full Version : 12GA chamber diam. Shells sticking in chamber

04-05-2013, 11:01 AM
Hey guys;\

So I said a while ago that my IGA sxs 12 ga after it is fired it is hard to break it open. I have narrowed it down to the dishcharged casings are causing friction on the sides of the chamber. THe brass is expanding.... What is the nominal dia. of the chamber suppose to be? could this be due to the chamber being undersized? or could it be oversized allowing the brass room to expand upon discharge? If anyone has an answer for me it would be greatly apprciated. I emailed a gunsmith and all his infinant wizdome answered back " pollish the chamber and clean the extractor"...... He totaly didnt answer my question which i asked above. Hopefully one of you guys have a resonable answer for me.

And yes his answer was a good one. but doesnt answer my question.


04-05-2013, 04:14 PM
Yep he sort of did with out great detail.
It sounds like the chamber needs some lapping compound or 600 wet/dry sand paper.
If all you have is wet/dry add some oil to it and sand the chamber.
If you have lapping compound. Take a spent shell and smear some in the chamber. Then take the loaded shell and work it back and forth tell the spent shell barely slips out.
Now when doing this please rember less is best and to take your time and check frequently.
As for the extractor can't tell unless you post pic's or I can physicaly hold it.

04-05-2013, 05:30 PM
Just out of curiosity, are you using Federal ammo with the aluminum heads on it ?

04-05-2013, 06:35 PM
Its probably not an issue of oversize or undersize; its more likely an issue of the chamber walls being a bit uneven. When the shell fires, it mates to the sides of the chamber, and if they are a bit "rough" you could have extraction issues. Polishing the chamber should help if not fix it entirely.

04-05-2013, 06:40 PM
Get a 12 guage brush, and wrap it in some fine steel wool, and run it on a cleaning rod thrown in a drill in the chamber for a while.

04-08-2013, 10:16 AM
well I am using Winchesters with the aluminum heads, but it seems to be with all ammo to answer ur questions blacksmithden.
Thanks for the comments guys I will start from there pollishing the chamber a wee bit.


M.T. Chambers
04-08-2013, 05:59 PM
The "cheapo" shells with alum. bases don't expand and then contract on firing like brass does, so you either have to follow the polishing recommendations every so often, or switch over to R-p Premiers, AAs., or Fed. GMs, for factory ammo or reloading.