Difficult Tune with 6BR

[Toby Bradshaw]

what is N?

Sample size. N=3 in your case.

 

[Patruck825]

What you have actually found is that the 6BR is ridiculously EASY to tune.

How about posting a photo of your ladder test?

I believe you are right, my lack of experience with BR when compared to other calibers led me to think that the lack of characteristics I observed across all other calibers was difficulty, when it was really the opposite. Thank you for your help.

I’ll get a photo of the whole ladder test up when I can grab a pic of it. It’s a bit cluttered with me circling and labeling groups but I am sure you’ll be able to make sense of it.

 

[Dusty Stevens]

Its so easy to tune it looks as if youre making it hard by looking for a problem. Get mr bradshaw some more data and youll see how forgiving it is. Larger sample size for sure. And great work mr bradshaw. That is excellent

 

[Gabe22BR]

sorry, misread your post, edited the original to respond.

Ok thanks.

 

[Raythemanroe]

29.9?


Ray

 

[Stan Taylor]

I don't own a chronograph, but I do know how to tune a BR rifle.

I don't know a single winning BR shooter who tunes with a chronograph without looking at group size/shape. Maybe I need to get out more.

View attachment 1056445

Just looking at your tune on a 6br what kind of powder are you getting 34.0 something grains of powder.

 

[Toby Bradshaw]

Just looking at your tune on a 6br what kind of powder are you getting 34.0 something grains of powder.

It's a 30BR with H4198.

 

[Stan Taylor]

It's a 30BR with H4198.

Understand

 

[Stan Taylor]

You guys got me confused now that's ok either way now I see the reason for more powder.

 

[Patruck825]

You guys got me confused now that's ok either way now I see the reason for more powder.

Sorry Stan I thought you were asking about my 6BR. Either way, I can fit 33.8 of RL16 in it. So that’s pretty close

 

[JohnMill]

Morning Gents,

I'm new to 6br, but not to reloading or shooting in general. All of my previous barrels in other calibers have had very pronounced flat spots in velocity that indicated my nodes.

However with this 6br barrel, it seems nearly every load shoots well, but there are no flat spots in velocity to indicate a node. Here is a ladder test i shot the other day.

26" Hawk Hill - 105 hybrid

H4895:

28.8 - 2810, 2817, 2814 SD:3.6
29.0 - 2831, 2826, 2821 SD: 3.1
29.2 - 2847, 2847, 2841 SD 3.4
29.4 - 2856, 2858, 2851 SD:3.6
29.6 - 2881, 2861, 2867 SD: 10.2
29.8 - 2882, 2878, 2895 SD: 8.8
30.0 - 2897, 2907 SD:7.0

I picked 29.3, loaded up 10 shots and had an SD of 3.8, it shoots well enough to keep it there. But i am just curious if anyone else has experienced this lack of flat spots with the "ultra easy to tune 6BR"

IMO if you were to do a "JB style ladder test" for vertical spread you would find a seperation in your loads indicating one that would (tend to) shoot better groups at distance. You do have to follow his procedure though ie 3hot loading shot round robin to even out conditions and you have to ink your bullets. We did it at the Williamsport Benchrest school. (The Original Pennsylvania 1000 Yard Benchrest Club). A great place to learn .
Jason Baney (JB1000) has the article on this site. I think you can do it at 300 yards but 600 would be better.
John

 

[DHuffman]

Move out farther. 100 yard testing was almost useless in my 6BR, it shot small from 28.6 all the way up to 30.4, Once i started testing it at 600 yards it all became pretty clear.

29.5 g varget +.011 with a 105 HVLD

 

[Webster]

Morning Gents,

I'm new to 6br, but not to reloading or shooting in general. All of my previous barrels in other calibers have had very pronounced flat spots in velocity that indicated my nodes.

However with this 6br barrel, it seems nearly every load shoots well, but there are no flat spots in velocity to indicate a node. Here is a ladder test i shot the other day.

26" Hawk Hill - 105 hybrid

H4895:

28.8 - 2810, 2817, 2814 SD:3.6
29.0 - 2831, 2826, 2821 SD: 3.1
29.2 - 2847, 2847, 2841 SD 3.4
29.4 - 2856, 2858, 2851 SD:3.6
29.6 - 2881, 2861, 2867 SD: 10.2
29.8 - 2882, 2878, 2895 SD: 8.8
30.0 - 2897, 2907 SD:7.0

I picked 29.3, loaded up 10 shots and had an SD of 3.8, it shoots well enough to keep it there. But i am just curious if anyone else has experienced this lack of flat spots with the "ultra easy to tune 6BR"

Tony Boyer looks at groups. Buy his book. I get bad SD & ES in my varmint rifle but it can shoot 1/4" groups. Your probably shooting longer distance than I am. Don't under stand why there would be a velocity flat spot related to group size. I understand that each bullet might leave the barrel at the same place in a vibration pattern but I think there is more to it than that. I am sure most serious competitors go by group size.

 

[johara1]

oh yes, I’m aware. That result was expected just explaining the flyer.
I do always patch the bore dry after cleaning. The first shot on a clean bore always chrono a a good 60fps slower.

I think you are wrong here, never shoot over a dry bore. If you want to experience copper that is how to get it. I have used a 50/50 mix of Kroil and Hoppes followed by a 1" patch take most out before firing but it leaves a film on the bore. 3000 rounds and no copper on a bunch of barrels.... jim

 

[Patruck825]

I think you are wrong here, never shoot over a dry bore. If you want to experience copper that is how to get it. I have used a 50/50 mix of Kroil and Hoppes followed by a 1" patch take most out before firing but it leaves a film on the bore. 3000 rounds and no copper on a bunch of barrels.... jim

Have never had a problem with this barrel collecting copper, thanks for the tip though. When I said clean, I meant of carbon and copper, the bore did have a light coating of oil in it, which I always do after a thorough cleaning.

 

[johara1]

Have never had a problem with this barrel collecting copper, thanks for the tip though. When I said clean, I meant of carbon and copper, the bore did have a light coating of oil in it, which I always do after a thorough cleaning.

I never had copper in no less than50+ barrels except at break in and I never will shoot over copper, shoot and clean one at a time till it quits. some say you don't need to do this but it flat works. It is also funny I never expearanced carbon in the bore till ran out of Warthog 1134.... jim

 

[mtang45]

I don't own a chronograph, but I do know how to tune a BR rifle.

I don't know a single winning BR shooter who tunes with a chronograph without looking at group size/shape. Maybe I need to get out more.

View attachment 1056445

I'm not familiar with how to read this kind of target. I understand the powder charge vs seating depth, but how do you read the corresponding groups to determine what works best?

 

[Toby Bradshaw]

I'm not familiar with how to read this kind of target. I understand the powder charge vs seating depth, but how do you read the corresponding groups to determine what works best?

Here's an explanation of that charge/seating depth test for my 30BR that I wrote in another thread.

 

[mtang45]

Here's an explanation of that charge/seating depth test for my 30BR that I wrote in another thread.

Very interesting; I will have to experiment with this method. Thanks for the explanation!