6BR- Ackley Improved 40 degree

[Stan Taylor]

Well here is my New 6mm br improved case I will test this weekend hopefully.

 

[tclaunch]

Looks deadly accurate!!

 

[22DASHER]

I’m calling that the 6 BRE!! For “extended”

 

[KenOath]

Well here is my New 6mm br improved case I will test this weekend hopefully.

Looks good am interested to see how it performs for you??

 

[Stan Taylor]

Looks good am interested to see how it performs for you??

I fire formed 2 rounds today to check chamber I will start forming about 50 pieces of brass tommorow an test loads for the last 600yd match an report good or bad thanks rushty.

 

[Clucknmoan]

Any feedback on these feeding from a magazine? Typical Dasher solutions I assume?

Edit: Detachable magazine that is.

 

[newbieshooter]

Well here is my New 6mm br improved case I will test this weekend hopefully.

Is it me or do the cases in the picture look different?

 

[KenOath]

I fire formed 2 rounds today to check chamber I will start forming about 50 pieces of brass tommorow an test loads for the last 600yd match an report good or bad thanks rushty.

No worries good luck.

 

[KenOath]

Is it me or do the cases in the picture look different?

Yep the one on the left is taller at the shoulder and has a shorter neck. Looks a little like a BRX but with a longer neck.

 

[newbieshooter]

Yep the one on the left is taller at the shoulder and has a shorter neck. Looks a little like a BRX but with a longer neck.

Thanks for the clarification. So the case keeps the original 30degree shoulder?

 

[kvd]

Thanks for the clarification. So the case keeps the original 30degree shoulder?

The shoulder for 6BRA (6mm BR Ackley Improved) is 40°. The 6mm BR Norma case from which it is produced has a 30° shoulder. Because the dimensions are very similar between the two cartridges, and there is no need to create a false shoulder, the 6mm BR Norma cases can simply be loaded up and fired in a 6BRA chamber. Very straightforward. About the only thing one needs to be mindful of is that if neck turning is needed prior to the first fire forming, a 30° cutter is required for the 6mm BR Norma brass to cut a few thousandths into the shoulder. If neck turning after the first or second fire forming, then a 40° cutter is to be used.

 

[Lee Black]

Tried out my 6BRA dies for the first time. I had a Forster 6 Dasher full length die shortened by 0.082" and the neck honed. Seems to be a very good match for my reamer specs (which closely mirror Alex's reamer print for base/shoulder diameter). I ordered the die from Forster shorter by 0.080" but it wouldn't quite bump the shoulder so had to take the last 0.002" off myself. Forster is advertising making the 6BRA dies as 0.082" shorter so it seems like others may have had the same experience as me.

I'm getting 0.0006" sizing at the base of the case after first firing, .4703 fired down to .4697 sized. Shoulder diameter goes from 0.460 down to .4585". Bumping the shoulder 0.001 to 0.0015 gives effortless bolt close. I had the neck of the die honed to .265 for no turn Lapua brass, current manufacture. I run a Sinclair carbide turning mandrel as my final expanding step to set neck tension. Neck expands about a half a thousandth to hit a final measurement of .2655 with 0.002 neck tension.

Runout is essentially zero, very consistent straight cases even though I'm doing it on a Dillon 550.

Happy with the choice of Forster dies, something to consider if you're looking at the varying die options.

What reamer did you use? Would like to use the same dies and reamer.

 

[Sheldon N]

What reamer did you use? Would like to use the same dies and reamer.

My gunsmith ordered it custom from JGS. I believe .104 freebore. .4605 at shoulder, .4715 at .200, FB dia of .244, case length of 1.570, .272 neck. You could basically use Alex Wheeler's reamer print which he's posted on the forum and just change it to a .272 neck, or I believe he also has a no turn reamer and could chamber one up for you.

 

[Stan Taylor]

Well I formed 28 pieces of brass at 125 yds in my 6mmbr improved 30 degree shoulder

 

[KenOath]

Well I formed 28 pieces of brass at 125 yds in my 6mmbr improved 30 degree shoulder

Wow looks promising just fireforming.. great range you have there to!

 

[Stan Taylor]

Wow looks promising just fireforming.. great range you have there to!

Rushty I just love the challenges of going to our long range matches an sometimes suprizeing the shooters I shoot with great bunch of gentleman they are an the ladies also they don't take no prisoner's we all look for that magic that's what keeps me going I will update as I tune with this puppie.

 

[KenOath]

Rushty I just love the challenges of going to our long range matches an sometimes suprizeing the shooters I shoot with great bunch of gentleman they are an the ladies also they don't take no prisoner's we all look for that magic that's what keeps me going I will update as I tune with this puppie.

Im with you there long range shooting is challenging and addictive, having great people to shoot with makes it all that much more fun to boot.

Good luck with the tuning keep us posted.

Cheers Rushty

 

[kneedtospeed]

That ash tray resembles a beer can

 

[kneedtospeed]

Or is that a WVa fire extinguisher??

 

[Stan Taylor]

Gentleman I need some ideas where to get resizing die for the 6mmbr 30degree improved I am going to play with temporarily I can improvise overcome an adapt but if it works good I would like the proper set up I don't think Harrell precision can provide what I need thanks. P.S I will contact an send cases to make a reamer to PT&G for a gauge an reamer.