Testing the 6BR / 95 SMK

T

TackDriver284

Handloader
Feb 13, 2016
2,311
1,558
Been using the 107 SMK and Varget in the 6BR recently, had a hard time to get one hole groups and it did .25 MOA at its best, and I switched to the 95 grain SMK to find max pressure / velocity, wind conditions 15 mph with some gusts
6BR, BR-4 primer, Varget, full sized bushing, .242" mandrel, once fired Lapua brass
29.0 grains - 2761, 2771, 2769
29.3 grains - 2798 , 2804, 2796
29.6 grains - 2817, 2827, 2815
29.9 grains - 2863, 2857, 2842
30.2 grains- 2883, 2885, 2878
30.5 grains - 2910, 2932, 2910
30.8 grains - 2950, 2954, 2921
31.1 grains - 2976, 2975, 2977 ( slight ejector marks )
31.4 grains - 3010, 2992, 3003 ( defined ejector marks )
29.3 grains is a nice start, and 30.5-30.8 is my pick, don't want to go higher due to pressure. 3000 fps with 31.4 grains!!! Dang it still made a very nice group.
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That is some fine shooting with an exceptional load. Excellent work on your part.
 
That's a good load workup. Have you tried CCI450 mag primers? The last 6BR I had got good results using Varget and these primers with 105 gr. bullets. Dan.
 
wvbuckbuster said:
That's a good load workup. Have you tried CCI450 mag primers? The last 6BR I had got good results using Varget and these primers with 105 gr. bullets. Dan.
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Yes I have tried both primers and the old Gold Medals with the 107's. I have tried different neck tensions, seating depths and .25 MOA was the best it could do which was exceptional accuracy. Thought I could try a lighter bullet and it sure shoots.
 
In my 1 in 8 twist barrel, I shot 70,87,95,100,105 and 107. All did well couple better than others but no problem of over stabilization with lighter weight bullets. As you I tried different primers. Standard, match and magnum. CCi450 held up to more pressure at top end loads without problems. Just my experience. Dan.
 
wvbuckbuster said:
In my 1 in 8 twist barrel, I shot 70,87,95,100,105 and 107. All did well couple better than others but no problem of over stabilization with lighter weight bullets. As you I tried different primers. Standard, match and magnum. CCi450 held up to more pressure at top end loads without problems. Just my experience. Dan.
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My barrel is a 8 twist and what speed were you doing with the 105/ 107's?
 
wvbuckbuster said:
In my 1 in 8 twist barrel, I shot 70,87,95,100,105 and 107. All did well couple better than others but no problem of over stabilization with lighter weight bullets. As you I tried different primers. Standard, match and magnum. CCi450 held up to more pressure at top end loads without problems. Just my experience. Dan.
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Dan, you’re an animal buddy! And here I thought you got that old
Remington from me cause you wanted a challenge!

Youre a man of many experiences(y)
 
Mark , tell me a little about these two rifles , both shoot great . who built them , and what action was used ? do you know if anything was done to the ignition ?
 
SJB358 said:
Dan, you’re an animal buddy! And here I thought you got that old
Remington from me cause you wanted a challenge!

Youre a man of many experiences(y)
Click to expand...
Well I bought that Ruger I traded you to scratch my itch for a Whelen. Just liked yours better. Was challenging getting used to the recoil, lol 😆
 
jimbires said:
Mark , tell me a little about these two rifles , both shoot great . who built them , and what action was used ? do you know if anything was done to the ignition ?
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The 6 BR is built on a trued Remington 700 short action, which is my 2nd 6BR, fitted with a 26 inch Bartlein heavy barrel, aluminum pillar bedded, 1:8 twist , A5 McMillian stock with cheek riser , ATACR NightForce 5.5 x 25, Jewel trigger. Built by Score High Gunsmithing ( Charley Robertson ) He has built me several rifles and they all shoot great.

My 2nd rifle, the 6. 5 x 284 is built by GA Precision, custom Templar II long action (built by Defiance Machine), 26 inch Bartlein barrel, 7:5 twist, A5 McMillian stock with cheek riser, pillar bedded, ATACR NightForce 5.5 x 25, Jewel trigger with 1 pound break. GA built me a few other rifles as well, and they shoot damn nice. They don't come cheap though.

What do you mean by done to the ignition?
 
Mark , these are both top notch rifles , built with excellent parts . the targets don't lie .


I don't know a lot about it , but I'd like to learn .
gunsmiths will work on the bolt , and trigger . they will bush the firing pin hole and machine the pin to fit , adjust firing pin fall , adjust firing pin protrusion , remove all or a lot of cock on bolt close , play with lock time , and things like this to get the optimum primer strike . some of this stuff is related with the trigger . pin fall can change just by changing out the trigger, affecting accuracy . by design some actions can't be made perfect, improved a little , but far from perfect . supposed to be some accuracy there when it's all trued up .

some custom actions are well designed . the smith just needs to get the trigger in tune with the action . other custom actions need work . I've read Jim Borden's actions are very good , out of the box . just set up the trigger to match .

I've learned there's a lot more to this than just hitting the primer . a few years ago I lowered a loads velocity ES , with a new firing pin spring .
 
Tack,
Great shooting!
Question, do you notice a difference between lapua virgin and 1x brass in your BR? I am going to start working on my daughter's and wondering how serious I should be with virgin brass.
 
Slimfinn said:
Tack,
Great shooting!
Question, do you notice a difference between lapua virgin and 1x brass in your BR? I am going to start working on my daughter's and wondering how serious I should be with virgin brass.
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Thanks Slim, I had used the 100 pieces of virgin many months ago when I used the 107's, once it was all fired, switched to the 95's. On my other rifle ( 6.5 x 284 ), the 1X fired brass used half a grain less powder than the virgin brass to get the same speed. Jimbires mentioned that fireformed brass will get a little more speed,,, the energy of the combustion is partially used to expand the virgin brass, once its expanded, the remaining energy is used on the bullet. So once its fireformed, there is no energy needed to expand the case, so its 100% energy on the bullet, hence the more speed achieved. Do some quick load development to find a load that is accurate with virgin brass and shoot it all. Once fireformed then check the load and adjust or tweak as needed to get the best load on the once fired brass.
What caliber are you planning to work on?
 
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