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Any testing with the 6BR 40deg shoulder?

Awhile back some guys were testing the standard 6BR with a 40 deg shoulder (NOT a dasher) and things were looking promising.
Has any more work been done along these lines? This was very interesting to me.

I believe Tim Claunch had a reamer coming of his design and that in particular was interesting.
 
It was the 6BR with a 40* shoulder not the BRDX, it sounded interesting.

I`d like to hear more too.....

Phil.
 
My design has a body length between the BRDX and Dasher. You can use Dasher loads and more forgiving on seating depth. Longer neck.

Have you had a chance to work with it any more Tim, velocity/accuracy? It's right there in the BR/Dasher family so I was thinking it should perform rather well if not awesome, longer necks are always great.
I was hoping you would be able to get the Dasher velocity in your case or close.

You wouldn't happen to have a comparison type picture of it beside the Dasher or BR would you?
Almost forgot, what are you calling it?
 
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Yes, I have 3 of my own barrels chambered and a friend, and outstanding F-Class shooter Brian Bowling, has had 2 barrels chambered. He tied the world record 20 shot string down in Palo Alto Louisiana, 2 yrs ago I believe with a 200 18X is some really tough conditions. I added a 2nd reamer in a no turn. It is a Dasher as far as loads go, have had no issues attaining same speeds and accuracy.

Comparing prints, the BRDX with 40* shoulder is .0937" longer to the shoulder than the BR case, the TAC40, my case, is .114" longer than BR case to shoulder, and the Dasher is .126". That small change effects the neck length and is noticeable side by side.
 
Yes, I have 3 of my own barrels chambered and a friend, and outstanding F-Class shooter Brian Bowling, has had 2 barrels chambered. He tied the world record 20 shot string down in Palo Alto Louisiana, 2 yrs ago I believe with a 200 18X is some really tough conditions. I added a 2nd reamer in a no turn. It is a Dasher as far as loads go, have had no issues attaining same speeds and accuracy.

Comparing prints, the BRDX with 40* shoulder is .0937" longer to the shoulder than the BR case, the TAC40, my case, is .114" longer than BR case to shoulder, and the Dasher is .126". That small change effects the neck length and is noticeable side by side.
Is their any velocity gain just by incorporating a 40 degree shoulder into a 6BR case?? I'm interested in incorporating one of the improved designs based off the 6mmBR into the neck/shoulder of a 6x47L... I think the 6BRBS has the most powder capacity.
 
Yes, I have 3 of my own barrels chambered and a friend, and outstanding F-Class shooter Brian Bowling, has had 2 barrels chambered. He tied the world record 20 shot string down in Palo Alto Louisiana, 2 yrs ago I believe with a 200 18X is some really tough conditions. I added a 2nd reamer in a no turn. It is a Dasher as far as loads go, have had no issues attaining same speeds and accuracy.

Comparing prints, the BRDX with 40* shoulder is .0937" longer to the shoulder than the BR case, the TAC40, my case, is .114" longer than BR case to shoulder, and the Dasher is .126". That small change effects the neck length and is noticeable side by side.
What is the length from back of case to shoulder.
Stan
 

The 6BR 40 degree looks pretty close to mine. What did your case length shrink to after fire forming? My reamer has a .269 neck and .125 freebore. The COW method was used for initial fire forming and then I started load testing with Varget and 4166. I have found a load with 31.6 grains of Varget that has shot a few dime sized groups at 300 yards (5 shot). I have a friend that has shot this load for 600 yard BR the last few years and done quite well. Velocity hasn't been tested yet, as I am more interested in finding a consistent load for MR F-class that is somewhere between the standard BR and the Dasher/BRX velocities. My guess is that it is somewhere in the high 2800's. Who knows how things will work out when we chase some of these rabbit holes...
 
I'm having a reamer made at JGS. right now, I think the velocity you are seeking would be around 2970, and a lot less work load them and shoot them…. jim
 
The 6BR 40 degree looks pretty close to mine. What did your case length shrink to after fire forming?...

I currently do not shoot or load for the 6BR Imp. 40°. I enjoy collecting cartridges, and especially any wildcats; that's how I have obtained these different cases.
 
Myself and a couple of my shooting buddys have finally gotten reamers made for the 6BR-AI (40 degree). The Ackley chamber is made where it just "crush fits" on the neck/shoulder junction on new 6BR brass. No need to make a false shoulder, jam the bullet in the lands , or any of the hastles of making Dasher, BR-DX, BRX or the like. I am fire forming with a light load, 27.0g H4895 and an old lot of Berger 105's that dont shoot good for me. The shoulder on this reamer is a little wider than most improves for slightly more powder capacity, .463 vs .460 for most BR's and Improves. I have a barrel chambered, but weather has been bad, so no load development with it. I have been experimenting since October with a 6BR-AI I hand reamered an existing 6BR chamber barrel to make a 40 degree shoulder using a BRDX reamer I had. It has showed a lot of promis to say the least. I load develop at 500 yards now. l have had one Dasher group under an inch (.900) since I have been shooting 500 yard for a year and a a half now. I had 3 groups in a row with the AI that were .8 with 3 different powder charges! I shot it in the Feb. "Dark Corner" match and opened with a 0.892, that group I was shooting slower, I found out that match that this particular rifles' groups would open up if I shot it too fast. Anyway, I finished 2nd in group that morning , loosing by .1 inches on a 4 target agg. to Chad Jenkins, a great shooter. Note, my rifle that match was listed as a 6BR on the equipment list, but was the AI. It likes Hybrids shot anywhere between 2900- 2970fps. I can shoot them 3050 with no pressure, but the groups noticable open over 2970. I am shooting 32.3g R-15 in this barrel. Note: Use Caution: this barrel has a .237 bore. That load may cause pressure in a .236 bore, work up to it! I actually shot up to 33.0 g, with no pressure, but groups opened up. I am really liking this round, it appears to be very accurate and consistent. I went to this round because I was tired of all the hastle of making Dasher cases. It is a "no turn" .272 neck to make it even more user friendly! Samuel Hall
 

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