I recently had a VZ-24 converted to 458 lott by a gunsmith who is well known to this board(he does not post here). It feeds and functions flawlessly.

I am returning the action to my smith for some additional work. When I pulled the barrel and upon glancing into the chamber I noticed something did not look right. I took a closer look and found that the rear edge of the chamber had been polished/chamfered. I am sure that this was done in an effort to make the round nosed bullets feed as well as they do.

Here is the problem: some of the "polishing" extends past the "belted" area of the chamber. At a couple of points it looks like a fair amount of the metal just ahead of the belt abutment was removed, to the point that the rear of the chamber is only slightly narrower than the belt recess. It almost looks like the step from belt recess to rear of the chamber has been polished away in a couple of places.

This does not seem right to me and I am wondering if I should return the barrel, with the action, to my smith and ask him to set the barrel back and rechamber it. What do you guys think?

I know a picture would be worth a 1000 words so I will try to post one in a day or two.

Are you saying that the area where the belt contacts the chamber "belt" has been partially polished away? That would be the area where headspace is determined.

Sounds like Jeff's idea on beveling the chamber.

quote:

Originally posted by Jim Kobe:
Are you saying that the area where the belt contacts the chamber "belt" has been partially polished away? That would be the area where headspace is determined.

Yes I mean the step that determines headspace. In two small spots, maybe 10 or 15 deg. of the 360 deg. of the circle, the step from belt recess(.532) to the main chamber(.513) is only half(.005+- instead of .0095) of what it should be due to the beveling/chamfering.

This would not affect headspace because that belt is still supported for about 90% of its circumference. And it is still somewhat supported for the other 10%.

What I am worried about is the cases being allowed to bulge ahead of the belt.

What do you guys think?

quote:

Originally posted by JBrown:

quote:

Originally posted by Jim Kobe:
Are you saying that the area where the belt contacts the chamber "belt" has been partially polished away? That would be the area where headspace is determined.

Yes I mean the step that determines headspace. In two small spots, maybe 10 or 15 deg. of the 360 deg. of the circle, the step from belt recess(.532) to the main chamber(.513) is only half(.005+- instead of .0095) of what it should be due to the beveling/chamfering.

This would not affect headspace because that belt is still supported for about 90% of its circumference. And it is still somewhat supported for the other 10%.

What I am worried about is the cases being allowed to bulge ahead of the belt.

What do you guys think?

I would make a chamber cast in order to see it better. Talk to the gunsmith who did the work and ask him what is what? We don't have the benefit of seeing the actual item in question so it would be a bit presumptive for us to comment. That said, a person want's as much case support as possible. Especially in an area where the brass is thin.

What does a fired case look like? Is it bulged?