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I am having both of these chamberings made up and am wondering how everybody is forming their brass.
I plan on using Bushing dies if this helps.
I need to buy sizing dies and am having the Smith make me seating dies from the chambering reamer.
Thanx,
Jim
I form both in more than one step. The 20 BR is much more involved but only because of the difference in neck size at the start.
For the 20 Practical, I use a 223 Redding Comp. sizer with a 20 cal carbide button assembly. I neck down the case in two passes, with the final bushing size of .225" for Winchester brass. Lapua brass will probably prefer a .226" bushing.
As I said, the 20 BR is more complicated.
1. New Lapua 6mm BR brass - Run through 22 BR form die
2. Run through 20 BR seating die with seating stem removed
3. Size with Redding type S sizer and .235" bushing
4. " " .232" bushing
5. Run through 20 BR body die
6. Turning necks might be something to seriously consider
* All sizing steps get Imperial Sizing die wax
I didn't have any other BR dies, so the 20 BR set was the best for me. If you already have a set for something else, just play around with different stuff to neck the brass down without inducing too much runout.
Oh, you'll have to trim the brass or it probably won't chamber. Trim length will be dependent on the reamer used to cut your chamber, but I use 1.530"
Also, be prepared to jam the bullets into the rifling with the 20 BR.
I use a .223 full length sizer with the de-capping rod removed, then a redding bushing neck sizer in two steps.
You might want to check out saubier.com they are dedicated to the smaller cartridges and on of their poster, Fireball, is Warren, the inventor of the 20 Practical.
I am waiting ona 20 Practical barrel from Northlander and Warren has been extremely helpful on the saubier forums, answering all of the questons I've had re case forming etc.
You've prob already read the articles on 6mmbr.com but here's a link for those who haven't:
http://www.accurateshooter.com/cartr...des/20caliber/