Chamber issue on my 450/400 3” Verney Carron double

[dougfinn]

Started doing a barrel break-in on my VC double and I noticed that the cases were fire forming with the shoulder advanced about 1/8” forward. I’ve included two pics, one of the cases lined up side by side and the other with the cases offset to show the amount the shoulders are off by. I don’t know that it’s a problem or not, but I will be reloading these and working the shoulder with a full length sizing die might shorten the life of my brass considerable, so I’m thinking neck sizing only. Any opinions will be greatly appreciated. Thanks.

 

[IdaRam]

Hi Doug, I think it is likely there is nothing wrong with the chambers of your VC. Probably just the shoulder location on the factory cartridges are a bit short. Obviously being a rimmed cartridge it headspaces on the rim, so shoulder location is less critical than a cartridge that headspaces on the shoulder. I wouldn’t be surprised if the factory purposefully sets the shoulder “short” on the cartridges to ensure that no trouble is experienced across the spectrum of rifles that have been chambered for this cartridge.
It should become evident when you full length size your fired brass for the first time if there is an issue. If you have to back the die off a bunch to avoid setting the shoulder back then you may have a chamber problem, but I don’t think that is likely. Much more likely the shoulder on factory cartridges is short before firing.
You probably already know this, but just for reference you should set your FL size die to where it just barely bumps the shoulder back a couple thousandths and also chamber check your reloads to ensure they chamber easily and your double rifle snaps shut and locks up easily. You should be able to “click” it shut and have the lockup feel the same whether it has cartridges in the chamber or not. If it feels different when you close it with cartridges in the chambers you may need adjust your sizer die to bump the shoulders a tiny bit more.
Let us know how it all works out.

 

[dougfinn]

Thanks for the tips IdaRam. I’ll resize them and see what comes out. I’ll keep you posted with my results.

 

[ve7poi]

Very sound advise

 

[degoins]

Dies will vary also so that they can accommodate the widely varying chambers of older rifles. For example, the chamber and bore in the left barrel of my Alex Henry double made in 1894 is much tighter than the right barrel.....even assuming that the right barrel was fired much more than the left.