6.5BRX or 6.5 Dasher

[cmillard]

what rate of twist would be recommended for either of these two rounds when shooting 123-130 grain bullets? i am very curious about these rounds for a benchrest rig.

 

[TX65]

I used 8.5 twist Krieger in my 6.5 PPCX and when I was playing the 6.5 BR.

 

[cmillard]

how did you like the 6.5BR?

 

[15Tango]

My 6.5 Grendel with an 8 twist stabilizes 140s all the way down to 1900 FPS so I'm sure you could get away with a 9 for 120s out of a 6.5 BRX or Dasher. Eight will for sure let you shoot anything you want though.

Wayne

 

[TX65]

6.5 BR is a nice cartridge and offers a couple more grains of capacity over the Grendel. While you can shoot bullets as heavy as 144 grains in both,,, I find the best bullet range is 81-115 grains because of the powder choices that can be used to drive them. When you start getting into heavier bullets, you can load varget or RL-15 in the BR case, but wont get the velocity that you can with the 6.5x47 Lapua.

My PPCX is pushing 108's to 3000 fps in a 28 inch barrel seated to 2.360" using N530. I also use a 114 VLD running about 50 fps less using the same powder. Based on my 1000 yard sight adjustments, the 114 VLD is .555 G1 BC. The difference in case capacity between the 6.5 PPCX which has slightly more capacity than the Grendel and the straight BR is about 1 grain.

In the 6.5x47 Lapua, a 130 Berger runs happily along at 2950 fps using RL-15 or Varget.

 

[cmillard]

kind of curious. if i do have this rifle built, what should i go with--6.5 Dasher or 6.5BRX? I am leaning towards the dasher. i think that i will have more stable brass as well as more case capacity.

 

[TX65]

Cole,

Whether BRX or Dasher would really be your call since in either case you will need custom made dies. I would look at the cartridge guides on 6mmbr.com and see how they can compare in 6mm.

You may even consider a BRDX to gain even more powder capacity if you really want to do something with the BR case and are willing to do the case forming steps.

Just me, I would go with a straight 6.5 BR and if you decide you want more powder capacity, add a 2nd barrel in 6.5x47 Lapua. Reloading dies in 6.5 BR are available from Redding and case forming is just necking up 6 BR brass. I do have a straight 6.5 BR die from redding and a converted redding competition seating die in 6.5 BR from my experiments.

Arne

 

[cmillard]

i do like the BRDX design in the 6mm improved versions. but, for a 6.5, i would like to go with the dasher version, since it has the shoulder blown forward a little for added case capacity. but, the 6.5 dasher does not have it blown forward as much as the BRX. i also like the fact that the dasher has less body taper then the BRX. now, if only the 6.5 Dasher could have the same amount of taper as the 6BRDX does. i would like to be able to push a 123-130 grain .264 bullet to over 2850 fps. i have thought about the 6.5x47, but since i already have 6BR lapua brass laying around already, i might as well stick with that.

 

[TX65]

Cole,

You may want to do some analysis on the final case capacity you choose and compare it to the 6.5x47L as a reference point since there is a lot of data out there and it will help you determine what you need to get to your goals.

In my barrel, the 6.5x47L will push a 130 Berger at 2950 fps in a 28 inch barrel and has pretty much run out of gas at that point (I did not see an increase in velocity with a 30 inch barrel). My load with the 130 is 38.2 of RL-15 or Varget with small magnum primer. The powder at that charge is right up in the shoulder so while not 100% full based on my seating depth, it is very close.

Just another tidbit,, In my testing years ago,,, the Lapua 108 Scenar was far more accurate than the 123 Scenar. Discussing the accuracy with Janne at Lapua in Finland, he did concur that the 108 had better balance than the 123. If you hold both bullets in your hand, they are identical in dimension except for weight. If you want to bump the BC on the 108,,, trim and point up the tips with the Whidden pointer. In the BR case, you can definitely get some velocity with the 108.

Another option to consider if you don't have a stockpile of 130 Berger's is getting some Cauteruccio VLD's. Bob makes a 119 VLD and can make you a batch down as light as 114 grains. Nice thing about the 114 vld is you can use the same powders as the 108 and not give up much in the way of velocity.