what size Redding neck bushing for .308 cast bullets??

[10mmShooter]

Hey Guys,

Just starting to cast for my .308, currently I use Lake City brass and use a Redding "S" bushing sizing die that acccepts the whatever neck size bushing you choose. Currrently when loading SMK168s in Lake City brass I use a .336 size neck bushing gives me the -.002 neck tension I prefer.

Soooooooooo ??? if I'm loading a sized .311 cast bullet in the same brass....am I to assume I should use a .339 neck bushing...obviously the Sierra jacketed bullet can take a bit more abuse during the seating operation... I'm hoping to avoid damaging my pretty lead projectiles during bullet seating.(yeap got a Lee expander die too to just sligthly bell the case too)

I coming up with the .339 by thinking I currently use .336 bushing for jacketed, my lead projectile is +.003 larger than my Sierra MKs, so .336 + .003 = .339 ??? size neck bushing..all using the same Lake City brass.

[Doc Highwall]

That should work. Make sure you use a M-Die that is .309"-.310" to give you the final neck tension along with a small bell on the case mouth.

[Calamity Jake]

I use the Redding Bushing neck die to load ott6 and a few others, I use a max .002 press fit of boolit in case neck, bushing ID is determanded by boolit dia. and 2 X neck wall thickness. First time case prep the case mouth gets a 30° per side inside chamfer, this elemanates the need for the M die.
I have 3-4 different lake city mfg. dated brass, each has it's own neck thickness plus some factory brass so I use bushing diameters from .334-.339, outside neck turning the necks may change these numbers.

[Larry Gibson]

Unless you are turning the necks also you will want a tudge of "fudge factor". I use a .338 bushing with most of my Match LC cases. One lot needs a .337 bushing. Then I use a .31 M die which uniformly expands the inside a very, very little (actually none on some cases) and gives a consistent bell to the case mouths. That gives me .002 tension on the .311 sized bullets.

If you get a .337, .338 and the .339 bushings you will have the bases covered for a lot of milsurp cases. WW, R-P and Fed cases many times take a smaller bushing as the case necks are thinner.

Larry Gibson