Barrel Testing Fixture Question

When testing a new short chambered barrel does the ammunition have to be sized differently? Smaller diameter? 
I have received new barrels that wouldn't chamber a factory cartridge completely into the short chamber; I've had them drop 75 percent into chamber.
I'm curious as to how the barrels are tested before being fit to the pistol; headspace and proper chamber.
Jon

Jon, I've never used a barrel tester.  But I don't see how you would test fire without a full chamber.  Since the hood is overlong, it seems to me you could finish chamber to zero headspace, test in the fixture, and still have to finish/headspace the chamber after the hood final fitting.

That's what I would think, but I'm also under the impression that manufacturer will take barrels back that don't perform. I wonder if chamber is finish reamed (with long hood) and tested. Them if performs good fit into pistol and thrn finish reamed again for proper headspace.
Jon

Jon;

I chamber, headspace and crown just as I would for the final installation..

Jon Eulette wrote:That's what I would think, but I'm also under the impression that manufacturer will take barrels back that don't perform. I wonder if chamber is finish reamed (with long hood) and tested. Them if performs good fit into pistol and thrn finish reamed again for proper headspace.
Jon

I have had to send very few back.. I also give the barrel a very good bore scoping.. I have sent more back for interior defects, than for poor performance.. I have explained the issues and have had little kick back.. Most want to know if their product is defective and or not performing.

Thanks Jerry. I figured you'd have a response ;p)
Jon

Greetings,

After 30 years of standing behind my barrel tester, I find Mr. Keefer's comments spot on.

With regards to 45 ACP barrels, if they are made to USGI Match Specifications they all seem to shoot well.

The barrel tester was soon renamed Ammo Tester. It is the AMMO that is the determining factor.

Only saw one barrel that shot poorly with commercial ammo. We trued up the barrel crown and it shot excellent.

Most of my current work is with the 32 S&W Long and 32 ACP. Here again, it is the quality of the AMMO.

Those that achieve good groups and scores inspect all components as they go. Yes, it is time consuming; but, the reward of shooting high scores is well worth the effort.

Cheers,

Dave