I have a250 savage RCBS fl sizing die that is making striations on the case necks. I took the stem and ball out and cleaned it the best I could , didn't help.Any ideas other than send it back to RCBS?

Inside the neck, or outside ?

outside the neck

Some possibilities.
If the striations actually engrave into the brass it might be hard contaminants inside the die. Disassembly and cleaning ( again ) may resolve that. Clean the interior die surface as well.
Prior to running into the die check whether case necks are dirty ( powder residue ) and clean first if necessary. This would stop introducing crud inside the die.
If the striations are not engraving but just leaving dark lines ( that you clean off with a little Meths on a paper towel ) it might come from excessive case lubricant remaining and building up inside the die. Again, disassembly and cleaning might might sort that. These examples happened to me and when I changed my methodology the problem went away. If you cannot prevent further incidence with the above it may be an actual die QC issue which RCBS should correct but I would say a QC issue is fairly unlikely.
Hope this helps you work it out.
Cheers.

I will lay better than even money that 30-06 is spot on.
You have introduced crud into the die-could be carbon, brass shavings, range mung whatever it is just disassemble the die, clean it and maybe then hit it with a little --very little spritz of a case lube spray VOILA your problems will be gone. The odds of RCBS sending out a scratched up die are less than me hitting the lotto. Just my $0.02

I have had several die sets that still had hard polishing compound leftover in the neck of the die.
Plenty of Hoppe’s on a cotton bore mop was required to spin the polish out.
My 264WM die was so bad I had to heat the die up before I could get it all out.

Cheers.

Never had a die with dirt in it from the factory; had plenty with dirt in them from users who didn't clean their brass of carbon and sand. Dies are real hard and hard to scratch, but sand is harder and that is what does it.
Don't forget that primers are made from ground glass too.
Unlikely you will be able to polish it out if it is really a deep scratch. Clean everything; start over. If still scratched, send it back and they will fix it.

Thanks everyone for your input
Steve

Years ago I got careless and ran some dirty
brass in two dies. A Lee and RCBS and scratched the bore of the die til it left scratches. Bits of white shale rock from range brass. I knew better, just got in a hurry.

I sent both back to their makers. Lee replaced their die, RCBS repolished theirs. Funny how that worked out.

I'm careful now and all brass goes in the shaker first. Then each case is inspected every time it's picked up. Sometimes good habits are learned the hard way.

George