Help with Brass

[ppd3180]

I finally got everything put together with a lot of help from the boards (Thank You) and have been enjoying my new set up. I am using a barrel and gas block from tp555 that is 10.5 with a pistol position gas block. But I have been having problems with my formed brass. I am using Redding Dies and have adjusted them all the way down to where they touch my tool head on my Dillon 550. When I form brass from 221 Fireball I have no problems. If I use new Winchest 223 cut and trimmed, they will load single shot but the bolt will not fully close when loaded from a mag. The bolt is about a quarter inch or less out of battery. No matter how hard I try I cannot get the Lake City brass that I bought already trimmed and formed to load. Once again the bolt is a quarter inch or less out of battery. It looks like the rear the case has scrape marks on it and it stops with about a quarter inch or less of the case out of the chamber. I also had this happen with some really old Corbon stuff that was formed from LC brass. Any Ideas on how to fix this, I would like to be able to use the 1000 lake city's that are ready to go. Will fire forming the Winchester stuff fix the mag load problem?

[tp555]

Fireform the win brass.The mil brass is thicker and springs back after sizing.You need a small base die or anneal the mil brass which is a pita.

[mstarling]

I had exactly the same problem using LC 97 brass. Solution was to size with a small base .223 sizing die, trim to length, size in the 300/221 sizing die to abt 0.003" shorter than a round that will just bearly chamber, and fireform.

Moderate fireforming load has been 147 gr boat tail FMJ with 13.9 gr of 2400.
My SS bbl made by tp555 is a 16.5".

Good luck!

[Fritzcat]

I had good luck with my first brass forming a couple of weeks ago. I bought Redding 2 die set FL and the form and trim die. I used Rem 223 Brass. I first ran them threw the form die then cut them at the shoulder with a 1/16 disk in a grinder held in a vise and the case held with a Lee Trim die shell holder in a cordless drill. Then deburred the mouth and running them on a RCBS Power Trimmer with the standard cutter at the same time. Tumbled them, then lubed them and ran them threw the Redding sizing die. I then ran them again on the RCBS Power Trimmer with the 3 blade head for the final length. I have been testing loads and the brass works great without fireforming them.

[ppd3180]

Thanks for the info. I have a small base die on the way to see if I can get the LC stuff to work. The Win 223's that I have fire formed are working perfectly. Thanks for the help.