Re-Sizing .311 Projectiles for .300 Whisper...

[sha-ul]

I do happen to have a hornady die set for 7.62X39 When I get home, I'll have to take my calipers to the expander.
I have several boxes of cast boolets, 150s, 170's& I think 190's. but was shaving the lead seating them. so set the expander long, and run the cases up till it just flares the mouth& since I don't normally crimp, add that step?

[Just Call Me...G]

Yes...

expand, seat and then crimp.

The expander should take care of any lead shaving issues you might have.


G

[sha-ul]

I got home last night& measured the expander on the 7.62x39& it is on the small side of .311, and I have 3 batches of cast boolets, 150fn, 170 fn& 193 rn. all measure .311. and the brass springs back a bit so I have .001-.002 interference fit. To tell the truth, I may not even need to size the neck after firing it may already be .311 if I don't size it back down.
Being this is a bolt gun, do I really need to worry about crimp?

[MMA10mm]

Sha-ul -

For a bolt gun with cast, the crimp is mostly just to take the flare off the mouth. The other function is to resist set-back if you are loading from the magazine. (Even hand-cycling from the mag in a bolt gun can cause set-back, because the lead bullets just do not hold as tight in the necks as jacketed.) If you are single-loading directly into the chamber, you are fine with just taking the flare off.

[Hoser]

Sometimes a touch of crimp will help ES and SD which helps accuracy past 75-100 yards. All your brass has to be the same OAL or you will get inconsistent crimps.