My RCBS 6.5x55 sizing/de-priming die is leaving a scratch about 1/4" below the shoulder. This scratch goes around about 3/4 of the case diameter. It doesn't seem that deep, but you can detect it with your thumbnail.
Never had this happen with any of my dies and all I have used is brand new brass with my 6.5...
Will this affect the life of my brass, or is it purely cosmetic?

Thanks,

Jim

You may have some debris or grit in your die. Clean it out well and hopefully that will fix it. If not and it's actually the die, contact RCBS, they have excellent customer service and most likely would replace it.

This scratch goes around about 3/4 of the case diameter.

This part makes me wonder if the shell holder and die are lining up square? You could try a little more lube just below the shoulder. Might help.

If you send it back to RCBS, send a couple of cases with it. That will help them in resolving the problem.

Cheezywan

I have had this happen several times when trash would get in my die. I now remove the decapping pin/neck expander rod and clean each die well with a good CLP before each use. I then spray the inside of the die with a spray resizing lube. If you manage to actually scratch the inside of a die with a grain of sand you will have to replace it. (I know from experience).

If the scratch disappears after tumbling, it is most likely cosmetic. If not, send it back to RCBS and they will likely repolish your die or replace it.

The grit that scratched your die may have come from polishing material left in the die's vent hole. Believe RCBS cautions to clean out the vent hole thoroughly along with the die before using it.

Thanks guys... When I got the dies, I took them apart and cleaned them as per the directions. I will do it again just in case. Kinda' doubt if that is it since that scratch as appeared on every case I have ever sized with it from the first.
Looked inside the die, and she has a nice mirror polish on the inside. I will try your guy's suggestions and that doesn't help, I will give RCBS a try. Heard nothing but good stuff about their customer service.

Thanks,

Jim

Just to clarify, you said that the scratch went 3/4 of the way around the diameter. A scratch is usually vertical on the case. Also check to see that the vent hole doesn't have a burr.

Dies are pretty hard but can be polished by the DIY. I have even opened up the bases of dies and reamed the necks. I may not fool with a $150 custom die but a low buck die, why not.

In the early 70's RCBS dies were so bad, came packed with grit, oversized the cases etc. you had to fool with them or throw them away. Also some of the guns from that era had really big chambers.

A scratch on the circumference could actually be in the rifle and shows up after the brass is worked in the sizing die.

Or you may indeed have a flawed die with a scratch or flaw on the circumference !!!!

I vote for Nitro's comment. There is no way for a sizing die to produce a circumferential scratch; only a longitudinal one as the case is pushed in. A circumferential tool mark is possible, but you should be able to see such a flaw in the die just by looking at it. You more likely have a circumferential tool mark in your rifle's chamber left by the chamber reamer. On firing, the brass flows out to fill that tool mark, leaving a raised area, then when you run the fired brass up into the die, the die burnishes that high spot so it shows up.

If it is small enough, your fingernail will have trouble telling the difference between a raised or indented flaw. The trick is to feel for that raised area before the brass is resized. You will probably find you can detect it on all your fired cases. Light chamber polishing could clean it up a bit, but as long as cases fire and extract normally and don't tend to crack or split near the flaw, I would ignore it.