6 BRX Load Data

[dirtworks5]

I am in the process of doing some load testing for my new build. It is a panda action w/ a bartlein 28 1/2" 1-8 twist barrel. I would like to shoot the 107 smk's. The ladder test I done at 300 was pretty promising with varget from 33.0 to 33.7. The other load I tried that had a very low spread was with 30 gns of 8208. I am wandering if anyone has any other data I could try. Also does anyone think the 115 dtac bullet would stabilize in the 8 twist.
Thanks,
Vern

 

[40X Guy]

Hi Vern, fellow member Fdshuster has a new 6BRX he was shooting at our local match using 107 Sierra's this past saturday. I believe he was using Varget. He will probably chime in when he sees this. One heck of an accurate little cartridge!

Frank

 

[alf]

I would like to shoot the 107 smk's.

Don't argue with your barrel.......

 

[rcw3]

I would like to shoot the 107 smk's.

Don't argue with your barrel.......

Good advice.

Robert

 

[bozo699]

dirtworks5,
Welcome the forum, there is a great bunch of guy's and gal's on here with a wealth of knowledge willing to help Enjoy.
My 6brx likes 34.5 grains of Varget with the 107's but every rifle is different and remember when using someone else's load always use caution and if there is any doubt in your mind at all reduce and work up, good luck. Oh and if Frank (fdshuster) joins in he is a very knowledgeable and a great guy, his advice will be sound, I have learned a lot from him. He has a month or so head start on me with the 6brx so he was able to give me some valuable fire forming advice. Frank, I didn't know you and fdshuster competed together, that is awesome I sure wish I could shoot with you two guy's that would be great.
Wayne.

 

[fdshuster]

Vern: I've settled on 33 grs. of Varget with the 107 SMK seated to touch, with BR4 primers, Lapua brass of course. Chamber neck dia. is a .270" for the "blue box" loaded neck dia. of .267", give or take a few ten thousandths. Tried as much as 33.7, but it didn't do anything the 33 gr. load won't. Chronographed velocities out of a Krieger 1-8, .237", with .077" freebore is averaging 2930 fps. Rather than getting into a "dog chasing its tail" situation, I have no plans to search for any other load combination. I know I'm going to rub some the wrong way, when I say that I've given up on VLD bullets, but for my level of abilities, and the distances fired ( 500 mtrs. max), the 107 SMK is an outstanding choice, in my rifles, without all the experimenting of bullet seating depths that seem to be a requirement. I've burned up a number of barrels always searching for that "magic" load combination, and when I may finally find it, the barrel is gone. I was fortunate to find the above load early in the program. As always, the load works in my rifle, only a suggestion for yours. How's that for a dis-claimer. p.s. Thanks to all for the kind words, but there are many here who are a lot more knowledgable than I. I'm still learning, and sometimes stumbling around in the dark.

 

[Rustystud]

I have loaded the 6mmBRX for several years. Shooting it in F-Class to 1000 yards. If you use a to hot of load you lose brass life due to primer pockets getting loose.
There seems to be three accuracy nodes acheiveable with the 6mm BRX with the 105-105 grain bullets. One round 2950 to 3000, another around 3020-3080 fps and a third around 3100-3150. I try to acheive the second because it give you a 150-200 fps advantage on the plain 6mmBR. It give the shooter the best accuracy for the best brass and barrel life.

I shoot a 30"-32" 1:8, 4 or 5R barrel. I have been able to get 3200-3600 rounds per barrel with acceptable accuarcy.
Nat Lambeth

 

[bozo699]

Nat,
to achieve your second node what powder and what is your powder charge? I agree with the nodes you came up with, I never pushed mine to the third node but found my best at the two lower nodes you mentioned I have a 1:8 Krieger finished at 28.25" I couldn't find any longer tubes at the time. It takes 34.5 grains of Varget behind a 107 SMK to achieve the lower end of the second node. Varget seems to have a very different burn rate lot to lot.
Wayne.

 

[tclaunch]

Wayne, the lot to lot differences must be real. With my lot of Varget, I could never dream of putting over 32 grains without a stiff bolt lift. 32 is max load for me to keep cycling the bolt smooth for quick follow up shots. This with Borden BR action as well as a BAT model B. 31.5 to 32 works great tho.....

 

[bozo699]

Tim,
What velocities were you seeing with the 32.0 grains? I don't want to sound like a liar but when working up the load I hit 35.5 without a sticky bolt or any obvious pressure signs just the groups were opening up a little. I really need to polish this load up I developed it two days before our first match (a month ago)
in heavy rain and winds at three hundred yards, while the wind was steady and not gusting I would shoot. From 31.0 to 34.5 grains of varget I was steadily shooting 3/4" at that distance, so I chose the load with the most velocity with best group and that was federal 205M's, 34.5 varget, Lapua cases, 107SMK's seated .012 jam, I can remember all that but for some reason I have forgotten the exact velocity with out going down to the loading room but 3028 fps sticks in my mind. Dave Kiff ground my reamer it has a .269 neck and .104 freebore with a light neck turning I have about ..002 neck clearance. I was running just under .001 neck tension but twice during load development we had to open the bolt and had to spend 20 minutes cleaning up a powder mess so I dug through my bushings and found a bushing that is giving me .0018 neck tension and seem to be working okay. Oh were sooting all this in a savage target action, my 6brx barrel will be going on my Diamondback (stiller) action that tends to get sticky bolt lift with hot loads with the 6*284 I have on it now. How is your competing going Tim I haven't talked to you in a while? your running a dasher now aren't you? Hope to talk to you soon.
Wayne.

 

[Rustystud]

I have acheived higher velocities (3150fps) with H-4350 and VV-550. remember I shoot long barrels 30-32" and I don't recommend shooting the higher pressure loads. I have shot loads over 34 grains but worked up to them. Each barrel is different. There is a method to the 6mmBRX madness, accuracy, and ecconomy. If you want to shoot faster shoot a .243, 6mmREM, 6mm/.284 or 6mm/06.
I like a load between 31.5 and 32.6 grains of Varget reaching a velocity 3020-3080fps with 9 feet or less extreme spread.
Nat Lambeth

 

[bozo699]

Nat,
Thanks for the info, I wanted to achieve 3100 but was unable to with the varget, I just got a 8# can of RL-15 I will try one day soon.
Wayne.

 

[tclaunch]

Wayne, I have both BRX and Dasher barrels, right now I`m back on the BRX bandwagon in a big way. Both my last two chamberings were with the BRX reamer. I finally had Kiff set both BRX/Dasher reamers up with throating to suit me. The 32 grain load is in the lower 2900 fps area. I have not been to a match since St Louis. The next 2 that I would love to attend would be to go back to Piedmont NC, and a distant second choice to that would be Yukon MO. Both these are coming up 2 and 3 weeks respecively. I think you will like the RL15, as I have been using it much more as of late, Tim

 

[dirtworks5]

To all that has responded to my beginning entry, this has been a wonderful discussion for me to watch happen. The load data favorite seems to be varget. I am going to do some more loading for that. I will be posting my results when I have a chance to shoot.
Thanks to all,
Vern

 

[fdiazverde]

Good morning. This is for every body. & many people know me
i shoot. palm bay & orlando 300 meters & 600 yards.
I have a 6 brx, brux 30 in 1:8, barnard action on Alex sigman H-H stock.
Here is. my gun has over 5 thousand rounds & stil shooting very well
I use Varget 32.8 grains & 105 vld, sierras & 108 berger bt no diference
still shoting hight scores. The only problem i have with it is the chamber is
very long & i have to set it @ 160 th of land. my name is frank diaz