needed dies,6mmBR to 20BR

[Joe O]

I am considering a 20BR build.I have tools for .243 and 20ruger,plus neck turning equip.I read that forming 20BR from 6BR brass can be done using the smaller neck bushing in a 22BR die.Would you just buy a 22BR neck bushing die w/Bushings to reduce the neck,or since I have no dies for BR cases,get the 20BR die with bushings to step down the neck,from 6mm.The 20ruger Hornady seating die will work for the 20BR.

 

[FURMAN]

I do not know if it is necessary but I do mine in many steps. First I run my 6br brass through a 22br seater die with the guts removed then I run it through a 22br sizing die with decapping rod removed then I use a .235 bushing in my 20br die(any br die should work). Then a .231 die(obviously you might need a different last size).

 

[Joe O]

Thanks for the info.What does the 22BR seating die do for you,as the first operation on the 6BR brass?I would think starting with a .235-.240 bushing die folowed by a .226,or whatever sizes .002 less than a loaded round,would be all that's required.Did you need to inside neck ream after sizing down to 20cal?Looks like a 20BR neck bushing die will be all I'll need.

 

[vlcakc]

Although I have resorted to the use of bushing dies over the past several years to neck down cases, it's certainly not my preferred method. The operation does have to be done in very small increments. If you look at a bushing you will quickly see why. The chamfer or bevel on the inside diameter of the bushing is very small. If you try to do too much diameter reduction in one pass you run the risk of deforming the neck or shoulder when the case mouth is forced into the flat part of the bushing. Using a outside neck deburrinig tool helps here as it puts a small bevel on the outside of the neck. This is why a fixed die can reduce diameter a great deal more in each pass. The shoulder angle of the die helps start the case neck into the die. To form 20 BR cases I start with a Redding 22 BR body die followed by a 20 BR body die. Then a 20 BR FL or bushing die will finish the process. A 22 BR seating die with the stem removed would probably work also, but I didn't have one and the body die was cheaper. When I ordered the 20 BR chamber reamer a "no-turn" neck diameter was specified so that reaming or neck turning would not be required. Good shooting! Vic

 

[FURMAN]

I got this info from Fireball. It worked great for me. Hope this helps you.


The bushing size will depend on your rifle's neck diameter and your brass neck thickness. My 20BR's chamber is a .237" neck. I use Lapua 6BR brass. I find that a .231" bushing is perfect for my rifle/brass. Also, be aware it is best to step down in neck size a few times when reforming the neck. So you may want to buy more than one bushing. My steps are this:

1) Run Lapua 6mmBR case into a .22BR form/trim die => .250"

,You can also use your .22BR seater without the guts to perform this first step. No need to purchase the form/trim die.)

2) Run case through a .22BR FL die with no guts => .240"

3) Run case through a 6mmBR Type-S die with .235" bushing

4) Run case through a 6mmBR Type-S die with .231" bushing and the .204" expander in the die.

This series of steps doesn't overwork the brass. Also, if you do resize necks in too large of a step they will not be dimensionally what you would expect. This is especially true in the last two steps. Notice that I only size down .005" and .004" on the last steps. For the first two steps I apply Imperial sizing wax on the outside of the necks. This isn't necessary on the last two steps.

 

[Joe O]

Thanks for the info.I see that the 204ruger seating die (hornady)that I have has a neck chamber that would work in one of the resizing steps.My plan would be to have a bump shoulder neck bushing die with enough larger bushings to reduce the neck in steps.I'm turning necks now for a 243AI,but would try to have a no turn neck on the 20BR near.230.

 

[KevinL]

Joe I will eat my hat if you can fit a br cass in a 204 seat die.
I start with a fl 22br form die then slowly shrink down with bushings Then I have a die we made with a blank and my 20 br reamer just short run the formed case threw it to form to my chamber (Less force needed to chamber for fire forming) then load I youse the 22br fl die to fl size if needed
Seeting can e easy with a 22 br seater or a little tufer (with flat bace bullets) with a 6 br seater has just a little more room for the bullets to move I have ruened brass with the 6 br seater and flat base bullets. I would by a 22 br 3 die bushing set and 3 or 4 bushings
Good Luck Kevin
I love my 20 BR

 

[Joe O]

Joe I will eat my hat if you can fit a br cass in a 204 seat die.

Good Luck Kevin
I love my 20 BR

Kevin,I was refering to the body of the Hornady 204ruger seating die.Turns out my 243 goes right in,but not the neck portion.I only checked it to eliminate another seating die for the 20BR.
I will talk to Redding,Forster,and Sinclair.Could be that all the neck bushing BR dies are the same,with only the bushing being changed to suit the caliber.That's my thought untill someone tells me different.