Gunsmithing Custom die leaving marks

[kaseyfield]

Hoping someone has seen this before. Had my Smith cut a custom die with my die reamer. Nitride finished the die.. finally used it. And it leaves Mark's.. brass is sized perfect. Is it just the finish leaving Mark's. Sized 12... far left one is the first then the next 11.. looks like a got better.. with a lil extra lube they were all smooth none went in real hard.. Thoughts?

Kasey

 

[RTH1800]

From what I can see in picture the marks are simply sizing marks that show your die is doing it's job. Pictures are a bit dark so I may be missing something. ??

 

[kaseyfield]

Fired case on left.. first sized case one right

Kasey

 

[FisherT&C]

Die blanks are supposed to be sent out for hardening after they're cut. The annealed surface is "sticky". You can try polishing out the blueing or have your smith polish it out on their lathe. The sodium nitride in the salt is a corrosive base and has an attraction to copper in the brass. The friction in the resizing process can produce enough heat to cause the case to stick to the die and that is what leaves the mark. You should have them hardened or you will eventually wear out the die.

 

[Davester]

If the finish is a dark rather than a light grey, it is probably salt bath nitrided rather than gas nitrided. Salt bath nitriding can leave a white layer that is hard and crusty that needs polishing out. It should have been quenched-polished-quenched as part of the process. I would have a good look inside and polish it and see how it goes. It doesn't seem to size as far down the web as I would have expected but if it's working for you all good.

 

[kaseyfield]

Sizes the case down perfect according to measurements... fired case is .342 neck... right below shoulder .577... and 3/4 down from shoulder is .585... base is still .580 on fired case...

Sized case neck is .337... just below shoulder .575.... 3/4 down .583... and base .580

Kasey

 

[BurnOut]

The inside of the die can be given a light polish pretty easily with JB Bore Paste, KG2, or similar. It doesn't take much, but it can make a big difference.

 

[rangerlong]

Scratched Cases: Causes and Cures - Redding Reloading Equipment: reloading equipment for rifles, handguns, pistols, revolvers and SAECO bullet casting equipment

Reloading equipment for rifles, handguns, pistols, revolvers, custom dies, bullet casting equipment, powder measuring and weighing equipment, bullet seating dies

www.redding-reloading.com

Read the cleaning section for redding’s process on polishing inside their dies.
I had to do this on all 3 die sets I bought from them. They all left markings on the brass similar to yours. I did 400-600-800 grit before I got brass that wasn’t all scratched up.