Help Fine Tuning 6BR

[jraulsten]

I decided to go beyond my typical 30 grains of Varget in the 6BR today. 5 shot groups at 100 yards. The .592" group is terrible but do you think seating depth will close it up? I ask because SD was very low, ES was low and velocity was averaging 2865. I would love to make this load shoot! If so, which way should I go and in what increments? These were shot with .020 jump. Pic is rotated 90 degrees to right.....

 

[jraulsten]

Forgot to mention the group was 30.8 grains Varget. Worst group but best SD by far.....

 

[GLTaylor]

What weight bullet?
Many find 31-32grs at 2920-2950 a sweet spot with 105s

 

[jraulsten]

What weight bullet?
Many find 31-32grs at 2920-2950 a sweet spot with 105s

105 Hybrids, Lapua brass, CCI 450 primers. I didn't think about going any higher but definitely no signs of pressure yet.

 

[Coyote Shadow Tracker]

First how many shots down the tube? Is it new - broke in? Barrel length? What make barrel? Twist rate?
If it is new broke in and 1:7 Try a few at 0.010 with 31.5 gr of Varget. What are you using to check the ogive?

 

[Coyote Shadow Tracker]

First how many shots down the tube? Is it new - broke in? Barrel length? What make barrel? Twist rate?
If it is new broke in and 1:7 Try a few at 0.010 with 31.5 gr of Varget. What are you using to check the ogive?

Also the most important thing is how old is the rifle, make, barrel manufacture, hammer forged/ button pulled, cut, shots fired, twist rate, action, trigger, Picture of the rifle?

 

[johnnyk]

Try backing down on your powder, say 30.0gn, jam the 105's and work back up to pressure. I'm running same bullet, brass, powder and primer but 30.2gn @ 2815fps. I'm using a 1-8t, 26" Shilen.
I only clean this barrel when the groups open up past .3".

 

[jraulsten]

Also the most important thing is how old is the rifle, make, barrel manufacture, hammer forged/ button pulled, cut, shots fired, twist rate, action, trigger, Picture of the rifle?

Impact 737 action, Bartlein 5R M24, 28", 1:7.5, chambered by Wade Studeville. 125 rounds down the tube. TT Diamond Pro Curve. Plan on using for PRS before I get too old to play

 

[jraulsten]

One thing to note is I used a different lot of Varget today and it seems to be around 20 FPS slower than the lot I have been using. The gun will shoot .4" 10 shot groups all day long with 30 grains of Varget but SD and ES are not desirable. I was center punching a 1 MOA plate at 500 yards the other day but when I got out to 1100 it was hit or miss and I attribute that to lousy vertical dispersion because wind was not that bad.

 

[Coyote Shadow Tracker]

Impact 737 action, Bartlein 5R M24, 28", 1:7.5, chambered by Wade Studeville. 125 rounds down the tube. TT Diamond Pro Curve. Plan on using for PRS before I get too old to play View attachment 277542

Absolute a prize possession for a PRS rifle. You can't beat, may match, but can't beat your components. I am very impressed! Can't see why you can't get to <0.25"easilly with that set up. Just few tweaks and you will be knocking them in the X every time. I would go back and start at 30.2 gr Varget and set at 0.10 off the lands. See where you are at by then. If good group and SD go to 31.5 and see how that goes. You have the best of the best for the rifle so it is up to the shooter now. Unless there is something incorrect with any or all of the highly precession components, Good Luck I am rooting for you! GREAT RIG!!!
Jill and I are currently almost building the same rig!
to bad your in TX we have a PRS range down the road from us.

 

[andrewsben]

Not the same bullets but using 105 nosler competition with almost exactly same barrel, mine is a larger profile though. Same length, 5r, 7.5 twist. I found some good loads over 30 grains of varget, but my.most accurate load, with smk 107s too, was 5 thousands jump on one and 10 thousand on the other, riding the exercise bike (getting old Dr said to exercise daily, pesh) and going by fading memory, with 28.5 on the 105s and 29.5 on the 107s, with varget. Both work really good at 100-300 yards (1/4 moa all the time sometimes a little tighter), which is mainly what the rifle is built for. But have taken it to a strip mine a few times and remember doing 8 shots inside a 4 inch spread at the 800 yard target. Going for the 1k things started to get a lot worse. Don't plan on it being a long range gun so not worried about finding a higher velocity node. Just my ramblings while exercising with nothing else to do. Need to setup a reloading station that covers my recumbent bike...

 

[Dollar55]

I decided to go beyond my typical 30 grains of Varget in the 6BR today. 5 shot groups at 100 yards. The .592" group is terrible but do you think seating depth will close it up? I ask because SD was very low, ES was low and velocity was averaging 2865. I would love to make this load shoot! If so, which way should I go and in what increments? These were shot with .020 jump. Pic is rotated 90 degrees to right.....

View attachment 277518

I run about .005 into the lands

 

[emp1953]

I decided to go beyond my typical 30 grains of Varget in the 6BR today. 5 shot groups at 100 yards. The .592" group is terrible but do you think seating depth will close it up? I ask because SD was very low, ES was low and velocity was averaging 2865. I would love to make this load shoot! If so, which way should I go and in what increments? These were shot with .020 jump. Pic is rotated 90 degrees to right.....

View attachment 277518

Change of seating depth will make a difference, the difference may be for the better or worse.

 

[Bret GRAVELINE Graveline]

Don't be afraid to try a different primer, I used to dabble in a occasional bench rest shoot and have been a hardcore harasser of prairie dogs and rock chucks for over 40 Years, having owned a fair share of one holers from 222 thru 6.5-284 I've found that a simple primer change could cut that group in half, bench rest primers don't always produce the tightest groups, have you tried shooting groups at 2 or 3 hundred yards? 1 of my 6.5-284s with a 1-7 twist would only produce 5 to 6 tenths groups at 100 yrs, this rifle weighed over 20 lbs and was fitted with a 42# nightforce scope, I tried every Sierra match king and Berger bullet I could get my hands on from 107 to 155 gr, it was only after I found that my groups fired on the 300 yard range were the same size as those i was getting at 100 yards did I learn to like that rifle, I have great results with benchmark and find 133 and 135 although this was with lighter bullets than you are shooting, good luck,