Leave behind

[white eagle]

What causes a small ring of lead to be left on the cartridge case or in the chamber
I have noticed it in my Encore and I just noticed it in my model 70
The cartridges are 475 Linebaugh and 358 win
A lead ring seems to more often than not is left behind
never noticed it in any other guns not sure if it effects accuracy or not

[Wayne Smith]

Absolute and complete lack of throat.

[white eagle]

ok so what does that mean?
Are you referring to freebore in the chamber?

[Hamish]

Instead of a throat you've got a forcing cone that swages a ring of lead off instead of a gradual throat that compresses the bullet down without shearing.

[white eagle]

is this detrimental to accuracy
I am shooting real good groups with the 358
I was thinking the boolit got away before the case fully opened

[Larry Gibson]

It means your bullets are probably sized larger than the throat of your rifle. The ring is from the alloy being scraped off the bullet entering the throat. Using oversized bullets is the fad on this forum but as you've found there can be too much of a good thing.

Sizing not larger than throat diameter will probably solve the problem. Accuracy may actually improve also.

[white eagle]

Thanks Larry
I was unsure which way to go

[Yodogsandman]

I had this problem, too. I found that it was from not belling the case mouth enough, causing the ring to be shaved or cut when seating the boolit. The ring was then covered up by sliding into a lube groove or from crimping. When belling or flaring the case mouth, enlarge it so the full width of the boolits gas check fits within the case neck by hand prior to seating. YMMV

[swheeler]

I've had this happen with a couple guns, lead deposited right at the end of the neck, stuck to the case. In both cases I was using formed brass that was way shorter than the chamber, 7.5 Swiss from 284 Winchester and 8x56R formed from 7.62 Russian, both with fast powders seems like it was 700X. When I got correct brass trimmed to trim length it went away so I figured that was the problem.