6BR charge weight test results / input

[eas1949]

What was your seating depth for the 107 SMK's?
Thanks
Eric

 

[urbanrifleman]

About pressure. With 30 Varget and the 107 I can shoot a quick 5 shot group. But, I cannot shot a 20 shot string without getting hard bolt lift. Even with around 45 seconds between shots at around 10 it gets tight. That's ok because at 29.4 I get zero pressure and awesome accuracy. 6BR ROCKS!!! Cheers Mike

My Criterion 6br never liked anything above 29.6.

My Rock Creek could go 30.6.

 

[Texas10]

What was your seating depth for the 107 SMK's?
Thanks
Eric

It was .015 off (jump).

 

[Lefty Trigger]

I have been doing some further testing with the H4895 powder and my gun seems to group just slightly better with it than the Varget. I have since reduced my bullet jump to .010 jump from .015. Have also been playing with Sierra's 85gr HPBT bullet for shooting the 300 yard range as opposed to wasting the 107gr bullets.

 

[boltfluter]

In my experience, you have really not seen what a 6BR is truely capable of until you seat the bullets at least .010 into the rifling. You may be shocked as I was the first time I tried this. Drop powder charge 2 grains and work up again. Good luck!!

Paul

 

[Lefty Trigger]

In my experience, you have really not seen what a 6BR is truely capable of until you seat the bullets at least .010 into the rifling. You may be shocked as I was the first time I tried this. Drop powder charge 2 grains and work up again. Good luck!!

Paul

This is true for some bullets, not all. I tried the seating depth test first and found that the Nosler 105gr likes a .005-.010 jam but the 107gr SMK likes a .010-.015 jump at least for me anyway. I would really like to get my hands on some Berger's to try but if I cant buy them locally I try to avoid them for fear of running low and having to wait for "brown santa" to deliver more, even the Sierra 107's is a crap shoot on being able to find them. Now the Nosler's and the Hornady's are always available.

 

[Dusty Stevens]

This is true for some bullets, not all. I tried the seating depth test first and found that the Nosler 105gr likes a .005-.010 jam but the 107gr SMK likes a .010-.015 jump at least for me anyway. I would really like to get my hands on some Berger's to try but if I cant buy them locally I try to avoid them for fear of running low and having to wait for "brown santa" to deliver more, even the Sierra 107's is a crap shoot on being able to find them. Now the Nosler's and the Hornady's are always available.

I wanted the rdf bullets to work in a bad way, hornady too but i get tired of trying

 

[Lefty Trigger]

I wanted the rdf bullets to work in a bad way, hornady too but i get tired of trying

I'm still working with the 6br and the Nosler's but finally got them figured out in my .308.

 

[JEFFPPC]

Been watching this thread because my new Shilen 6BR barrel seems to hate the 105 HPBT Hornaday that my X-Caliber barrel had an affinity for. So bought several boxes of 107MK to try out.

My results were very similar to yours. Best accuracy was 29.0 Varget and 30.2 cratered the CCI 400 severely. I didn't chrono it, but simply can't beat the results on paper. As best as I could measure it, the 3 shot group measured .08 (100 yds), so I'll go with that and reaffirm it with at least 20 rounds before putting the tuner back on.

Wish I still had access to a 500+ yard range, but developers nearby got a judge to shut it down.

Edit to correct primer used, CCI 400, not the Fed 205

Texas, why do you take the tuner off for your initial load work up? I don't understand that reasoning .

 

[Texas10]

The tuner will never correct for a bullet that the barrel just doesn't like. I started with the tuner on and a common load of 30 gr. Varget and would make a tuner adjustment, get a coupe of rounds into a tight group, and then a wide flyer. Eventually I took the tuner off and after several tries to get the bullet to shoot in the new barrel, it became apparent I was wasting my time and supplies.

With the tuner off and the thread protector on to minimize harmonic changes, I performed an OCW check with the new 107MKs. Now that the load is fairly settled, I'll put the tuner back on and see where it goes.

Thanks for your interest.

 

[JEFFPPC]

I have had 3 rifle with tuners for competition I have used for 8 years. A but the tuners on set at a zero point then develope the best load I can , expecting to get repeat 3 shot soups in the middle ones or less. At that pint I now go either direction with the tuner to fine tune a sweet spot. Works great for me. I wouldp not have a comp rifle whithout a Bob Greene tuner. Good shooting.