I am a newer reloader with somewhat limited experience and last year I decided to start reloading for an Older Savage 7mm Rem Mag that I have had for awhile and all has been fine. After shooting that rifle for a little while I got the bug for a new custom 7mm that is being built now. I decided for the new rifle I will get all new components just for that gun and start fresh. I was also borrowing the 7mm Rem Mag RCBS FL die and decided for the new rifle I would would purchase a new Redding Type S Bushing Die. I purchased 200 pieces of new Norma brass and purchased 500 175 Berger EOL's.
While waiting for the gun to be built I wanted to get some brass prepped and I decided that since the brass was new I obviously didn't need to resize it but I wanted to run it through the die to even out any small dents in the neck so I didn't screw the die down all the way so it never touched the shoulder only the neck. For whatever reason I used the RCBS die to go through this process. Since running some brass through the RCBS I purchased a couple of bushings too.
After running some brass through the RCBS die and doing some reading about selecting bushing for the Type S I was curious on the differences between the 2 Dies and here is what I found. Measurements using Mitutoyo Digital Calipers
RCBS FL Die
New Virgin Norma Brass, Neck OD - 0.309"
Inserted Brass through Die, Neck OD- 0.313"(I was surprised this increased the OD)
Inserted Bullet, Neck OD - 0.313"
Expander Ball OD - 0.283"
Type S Die
Inserted Bullet, Neck OD - 0.313"
Pulled Bullet, Neck OD - 0.311"
Used 0.309 Bushing on brass that was sized by RCBS(0.313 OD) and it ended up at 0.310" using calipers
Expander Ball - 0.282"
I found it pretty interesting that the RCBS die left the neck at 0.313 and after inserting a bullet the neck OD did not change, a bullet can not be inserted into the brass by hand either. When I inserted the bullet in the brass being sized by RCBS there was obviously minimal to little effort at all and when inserting the bullet into a piece of brass that was ran through the 0.309" bushing there was noticeably more relative effort.
Moving forward, since the brass sized by RCBS die has no relative neck tension I guess the question is if I am staying with the Type S Bushing die for everything should I just resize necks with the .309 bushing and move on for the first firing and maybe try larger bushings later, or try a 0.310 or .311 bushing to get to the 0.002- 0.003" of neck tension now. Using the 0.309 bushing gives 0.003" of tension now too, but after first firing maybe that changes.
Any advice would be appreciated.
While waiting for the gun to be built I wanted to get some brass prepped and I decided that since the brass was new I obviously didn't need to resize it but I wanted to run it through the die to even out any small dents in the neck so I didn't screw the die down all the way so it never touched the shoulder only the neck. For whatever reason I used the RCBS die to go through this process. Since running some brass through the RCBS I purchased a couple of bushings too.
After running some brass through the RCBS die and doing some reading about selecting bushing for the Type S I was curious on the differences between the 2 Dies and here is what I found. Measurements using Mitutoyo Digital Calipers
RCBS FL Die
New Virgin Norma Brass, Neck OD - 0.309"
Inserted Brass through Die, Neck OD- 0.313"(I was surprised this increased the OD)
Inserted Bullet, Neck OD - 0.313"
Expander Ball OD - 0.283"
Type S Die
Inserted Bullet, Neck OD - 0.313"
Pulled Bullet, Neck OD - 0.311"
Used 0.309 Bushing on brass that was sized by RCBS(0.313 OD) and it ended up at 0.310" using calipers
Expander Ball - 0.282"
I found it pretty interesting that the RCBS die left the neck at 0.313 and after inserting a bullet the neck OD did not change, a bullet can not be inserted into the brass by hand either. When I inserted the bullet in the brass being sized by RCBS there was obviously minimal to little effort at all and when inserting the bullet into a piece of brass that was ran through the 0.309" bushing there was noticeably more relative effort.
Moving forward, since the brass sized by RCBS die has no relative neck tension I guess the question is if I am staying with the Type S Bushing die for everything should I just resize necks with the .309 bushing and move on for the first firing and maybe try larger bushings later, or try a 0.310 or .311 bushing to get to the 0.002- 0.003" of neck tension now. Using the 0.309 bushing gives 0.003" of tension now too, but after first firing maybe that changes.
Any advice would be appreciated.
