Need some BR Education

[Bob3700]

A fellow was shooting his 6 mm BR the other day and had one of the new Garmin chronographs. Was curious to see what the display looked n how well it functioned.
He was shooting Berger 105 Hybrids using VV 150 powder.
His muzzle velocities were in the mid 2900 fps range. I was really surprised to see that high a velocity from a straight BR with 105 gr bullets.
My BRX with Sierra 107s runs a muzzle of right at 3020 fps.
I am wondering why I am going to the trouble of fireforming brass for a wildcat and only seeing 70 fps or so improvement in velocity?
Am wondering how long BR brass lasts at those velocity levels, and what special throating that straight BR must have to gain the extra powder capacity?

 

[Raydee]

Using 105's and VV150 I am nowhere close to that velocity. He must be loading pretty hot?

 

[SSchnd]

Bob are you talking about Ken F?

 

[R L U]

Using 105's and VV150 I am nowhere close to that velocity. He must be loading pretty hot?

A fellow was shooting his 6 mm BR the other day and had one of the new Garmin chronographs. Was curious to see what the display looked n how well it functioned.
He was shooting Berger 105 Hybrids using VV 150 powder.
His muzzle velocities were in the mid 2900 fps range. I was really surprised to see that high a velocity from a straight BR with 105 gr bullets.
My BRX with Sierra 107s runs a muzzle of right at 3020 fps.
I am wondering why I am going to the trouble of fireforming brass for a wildcat and only seeing 70 fps or so improvement in velocity?
Am wondering how long BR brass lasts at those velocity levels, and what special throating that straight BR must have to gain the extra powder capacity?

For your thoughts about extra power do a 6BRA instead. All the power of dasher and simple as a BR.

 

[ashooter]

105 and 30 grains of vv150 26" barrel I am at 2838 avg.

 

[HTSmith]

I've been able to get over 2900 fps out of N150 in my 6br without undue stress on the brass. I just didn't find accuracy there. It shot at about 2850 fps--same as Varget. Check out this thread https://forum.accurateshooter.com/threads/vv-n150-loads-in-6-dasher-or-straight-6br.4099275/

Edit to add this was with 103 Gr custom bullets.

 

[Contender]

Well dang, I hate to throw my two cents in but have a straight BR pushing a VT at BRA speed at 30.7 . No pressure signs and will test seating depth next. More to come I am sure. But very capable of 2900 + .

 

[Contender]

Varget powder.

 

[Allen Corneau]

Not completely relevant, more just an additional data point...

6BR, 26" barrel, 1:7.5 twist
30.0 grains of N150, Berger 115 VLD, CCI 450 primers, Lapua brass

This combo gets me ~2740 fps.

 

[Bob3700]

I have experienced lots of powder that delivered exceptional velocity coupled with excellent accuracy. The lot of powder changed and the velocity n accuracy went away. Sometimes the planets line up to produce unusual results n ur lucky to benefit from those circumstances.

 

[JEFFPPC]

Many years with the BRX and 107s taught me the magic number was 2990. Over 3000 not the answer.

 

[Hunter2678]

Well dang, I hate to throw my two cents in but have a straight BR pushing a VT at BRA speed at 30.7 . No pressure signs and will test seating depth next. More to come I am sure. But very capable of 2900 + .

barrel length????

 

[alf]

I have always ran my Dashers at 3075 in my 1K guns with 105 Bergers.

20 firings on the brass & still going strong......

 

[Dgd6mm]

I run 105 bullets at 2865 with IMR4895.

 

[Contender]

barrel length????

28"

 

[Dgd6mm]

28"

 

[HTSmith]

I have always ran my Dashers at 3075 in my 1K guns with 105 Bergers.

20 firings on the brass & still going strong......

That's smokin. Do share your load?

 

[alf]

That's smokin. Do share your load?

Generally no, that particular lot of Varget is on the slow side & I shoot moly plated bullets.