6Br Hates Varget and 107 SMK

[ShootDots]

If your groups are "scattered" all over, chances are it's just the bullet.. I would NOT count out Varget>>>>just try another bullet.

 

[swd]

I apologize for any confusion. I new to diagnosing problems.

I had to look up the shipping order its a 1-7.5 twist NOT 1-8 twist with a .237 bore



1. No, my groups are not a ragged hole
2. Its more scattered all over over.

3/4 has me confused.

I actually thought about doing that. All of these tests were preformed off a bench and I can usually achieve 1 hole groups IF I am doing my part that day.


I can possibly do some testing tomorrow at 100 yards if you would like some tests redone for better clarification.

What kind of speed is your barrel making? if you can hit 2920 there is usually a nice node there for 107's. Is you bolt bushed and firing pin turned down to .062"? If not you probably wont get that high without piercing primers, and some barrels won't get there anyways. There is a slow node around 2770. Put the 107's in the lands until the marks are square. This has held 10 ring on every F target I've ever shot at 600 and that's half the size of the sling target.

 

[bored184]

If your groups are "scattered" all over, chances are it's just the bullet.. I would NOT count out Varget>>>>just try another bullet.

If that ends up being the case then I will switch but my wallet really likes the SMK over Bergers.

What kind of speed is your barrel making? if you can hit 2920 there is usually a nice node there for 107's. Is you bolt bushed and firing pin turned down to .062"? If not you probably wont get that high without piercing primers, and some barrels won't get there anyways. There is a slow node around 2770. Put the 107's in the lands until the marks are square. This has held 10 ring on every F target I've ever shot at 600 and that's half the size of the sling target.

I don't think the velocities ever got the high but my notes are at home. I do know my bolt is in desperate need of a bushing job. Even on light loads I get cratering around the primers.

 

[theallcineyes]

While not ideal, RL15 is a pretty common powder to run in the BR's. I'd try H4895 or a different bullet.

 

[swd]

If that ends up being the case then I will switch but my wallet really likes the SMK over Bergers.


I don't think the velocities ever got the high but my notes are at home. I do know my bolt is in desperate need of a bushing job. Even on light loads I get cratering around the primers.

Get that bolt bushed or it will ruin your day especially if you have a Jewell trigger. Plus you'll never find an upper node and if it's as bad as you say maybe not even a middle node. It's probably not, but could be your problem right there that your not able to get it up into a node where it wants to shoot..

 

[Evan]

Pictures will help.

I'd try hard jamming the bullets, but my initial gut reaction is that if you know you can shoot 0.25moa, and the gun is scattering them, with a 6br and 107smk, then the barrel or your reloads are bad.

 

[KenOath]

This is out of a 30in, 1-8 twist Krieger barrel attached to a Remington 700 action. Ive been using Lapua brass and CCI BR4 primers.

I don't have my notes with me so I am doing this from memory. I did a ladder test from 28.0gr - 30.0gr of Varget with 107 SMK, the results were inconclusive and the velocities were not great. I pushed it with another ladder test from 30.0gr - 31.0gr of Varget, the velocities were great but sporadic. I say sporadic because the velocities did not jump incrementally like you would expect and some actually went down, I was using .2gr increments in my jumps. I shot a couple 5 shot groups with some possibilities from the last ladder test and at 100 yards the groups were 3/4in at best.

My reloading technique could use some practice but some of the above tests were done twice just to make sure I didnt screw up and get my loads out of order. I have also suspected my RCBS Chargemaster to be on the fritz.

What were conditions like when testing was done? Did you have flags out?

 

[DennisH]

The 6mm BR is one of the most accurate cartridges in existence

https://www.accurateshooter.com/cartridge-guides/6mmbr/

I have read "hours" of articles on many calibers in "Accurate Shooters" cartridge guides. Their articles contain some of the best information I have read. Many articles from shooters in this Forum has been very accurate and informative.

I posted a link above to the 6BR guide. It's long, but very informative. I distinctively remember changing primers from CCI 450's to Remming 7 1/2's, I changed NOTHING else, this rifle shoots out center holes anytime now when I am up to making it happen. All by just changing primers.

Some of the articles provided information that was "dead on" with my rifle/rifles.

I have several 6mm's including my 243 which is "deadly" accurate 500 plus yards.

I have dialed in many 6mm's, some with ease. I have a 6.0x47 Lapua that was the hardest for me to find a load for it. FWIW, my 6.5x47 Lapua was simple to dial in, and remains one of my favorite calibers.

As stated above, changing primers only, trying different bullets, trying different seating depths have "all" made a difference in my patterns, and on almost all of my LR Rifles.

The barrel you have should make your rifle a "tac-driver"! I turned out my 6BR barrel liked RL15 the best. Load up several rounds, at least 10 or more for each group. Don't change anything, but use different bullets, BIB's, JLK's, Secarns, etc., and it's amazing the difference it makes. If you fine one that stands out group wise, then start trying different seating depths with this load. Some like to be jammed, some like being way off the lands.

OP...you say it is your midrange rifle ,,,so you are not a benchrest shooter ,but are expecting benchrest results,,,let a benchrest shooter sit behind that rifle and you may see "benchrest" results,,,Roger

The Quote above! I have witness this with my own eyes! I was at the practice range on weekend, and a person was trying to dial in his news "LR" Rifle as he called it. It happened to be on of my favorite calibers. He was watching my groups, and I was looking at his target with holes all over the target.

We started talking, turns out he was watching my groups. He stated he hated his new rifle and just might sell it. I told him don't jump to any quick decisions or solutions with his new gun. This is when he stated he was watching my targets. He asked if I would shoot his rifle and see what I thought. I stated with one requirement, "I" would have to use my own ammo. He checked it out and then told me to go for it! I use his targets. I never said anything, and he didn't ask. So again it was time to change out a few targets to change.

He was still looking at his Target's, then starting to look at mine. He made the statement he would love for his rifle to shoot groups like this. He then asked if I knew where my 3 shots hit the target. I told him I did. He asked me to point them out. I did.

The 3 shoots I put in his target, well a dime would completely cove all 3 holes, a very tight cloverleaf group. He instantly changed into a monster and cussed all the way back to the line. I told him to find a bullet his rifle loved, stick with it, then show up at the next LR match after he put in several hours of trigger time on the rifle.

He didn't fire another shot that day, he loaded up his van and abruptly left the range. I hoped he learned something! This is many shooters problem from their very start. Learn the basic's first.

I hope some of the above helps him/you. There are many things we didn't mention that will make a difference.

Take Care, and Good Luck,
Dennis

NOTE: All rifles and calibers are different

 

[bored184]

Thanks for all the helpful comments and suggestions so far. The bolt is being sent out tomorrow for a bushing job and when I get it back I will get back to testing.

 

[cmillard]

30.3 of varget works well. Some say not to jam a 107 Sierra, but in my Krieger, 107 sierras shot best jammed .015 ITL

 

[Dusty Stevens]

If you put 30gr of varget in there and it doesnt shoot after a few seating depths you need new bullets. Dont waste your life trying to make a bullet shoot that wont just because of cost. I mean you can even do this with some hornady blems and never get where you want to be

 

[spitfire_er]

I'm getting my 6br tuned in as well. Started with H4895, and 105 A-max's. Didn't shoot well, Varget & 105's, better, Switched to 107's and varget, getting down to sub 1/4 MOA @ 200. Now doing fine tuning. Only 50 rounds down the barrel, so I think the barrel may start to be settling in as well.

Try a different bullet. If I shoot a string and it's not showing, I move on quickly.

 

[TAJ45]

My somewhat limited hands on experience would be to shout.......Change Primers. BEFORE you give up on the boolits.
My well smithed, Grizzly II 6BR did NOT like the Tula magnums. Round group but less than mediocre accuracy. The same rig that has shot .099 moa, 4 shots (first was cold bore) @ 250 yds out back. 30.2 Varget, 450s, non-tipped107s Sierras but don't remember seating depth.

 

[BenPerfected]

Consider threading for barrel for a tuner. It will save you considerable $ in ammo cost and barrel wear. Pick your best load and don’t change anything but your tuner.
Ben

 

[a6mmbrman]

What about the scope? Is it proven? What about the bedding? The barrel,bullets, powder, primer and cartridge that you have chosen have been proven many many times. I’d be looking for problems other than the load.

 

[bored184]

What about the scope? Is it proven? What about the bedding? The barrel,bullets, powder, primer and cartridge that you have chosen have been proven many many times. I’d be looking for problems other than the load.

You bring up some good questions. The scope is a Sightron SIII, it shot well on top of my dads 40x in 308 buy I'll double check it. I dont think it's a bedding issue because it sits in an Eliseo chassis.

When I get the bolt back from being bushed I'm really interested in trying different seating depths. I've had a number if shooters tell me that 107s jammed into the lands shot really well for them.

 

[TAJ45]

One possibility that has not been mentioned: firing pin spring....
I have read HERE, where that has caused a good shooting, load proven rig to drift south. R/R of the spring solved the problem immediately. Justa FWIW.

 

[bored184]

One possibility that has not been mentioned: firing pin spring....
I have read HERE, where that has caused a good shooting, load proven rig to drift south. R/R of the spring solved the problem immediately. Justa FWIW.

Its a relatively new action.


I just got the bolt back from being bushed! If I do 30gr of Varget what seating depths should I try?

 

[JFrank]

Its a relatively new action.


I just got the bolt back from being bushed! If I do 30gr of Varget what seating depths should I try?

run an abbreviated ladder test 29.0-30.2 .2 increments with 107 Sierra about.015 off a jam using CCI BR-4 primer .

You should find a node quite easily

 

[Texas10]

run an abbreviated ladder test 29.0-30.2 .2 increments with 107 Sierra about.015 off a jam using CCI BR-4 primer .

You should find a node quite easily

Jim,

I just took your suggestion on testing the 107MK in my new Shilen 6br and found gold at 29.0 Varget and .015 off. Three rounds into a .08 group at 100 yds. Now to confirm it and then put the tuner back on.