New 6BR Rifle help

[jloehle]

I am building a new 6BR rifle (on a Rem700 action). There are so many variables with this cartridge!

Mostly, I will be shooting a 100-600 yard match (prone). I am trying to figure out what twist rate to get on the barrel. I had assumed a 1:8, but want to make sure that will still shoot well at the 100 yard if I use the heavier bullets (105s for example).

The match shoots at 100 yards, then moves to 300, 350, 400, 450, 500 and then 600. I had assumed something like the 105 Berger VLDs would be good for it, but am worried about the 100 yard shots. Would you load 2 different bullets for the match? If so, how much lighter would you go?

But the first important question is the barrel twist. Probably going with a Heavy Varmint taper on a SS barrel that is at least 31" as a blank.

 

[swadiver]

My 8 twist 6BR Krieger barrel shoots 80 gr Berger FB Varmit bullets in the .1's and .2's @ 100 yds. it is throated to use 105 gr bullets

 

[dkhunt14]

You don't need over 29 finished and it will still allow for a rechamber or two. Matt

 

[WyleWD]

I have a Rem 700 with a Heavy varmint taper Kreiger in 1-8 twist that I occasionally shoot in Varmint matches. It finished at 28 1/2 inches. In my experience it is a very good candidate to take two loads to a match such as you describe. One load with lighter bullets for shorter ranges of 100-300yds (I use either 80gr BT or 95gr BT). My best scores for these ranges has been with bullets from Precision Ballistics.

As for the longer ranges, you're on your own there. You will have to see what bullets your rifle likes. I'd suggest you try some of the 105gr Hornady HPBT as I have had better than expected results with them in my limited testing of them. And bone up on how to sort bullets no matter what you try at the longer ranges. JME. FWIW. WD

 

[RonAKA]

I am building a new 6BR rifle (on a Rem700 action). There are so many variables with this cartridge!
Mostly, I will be shooting a 100-600 yard match (prone). I am trying to figure out what twist rate to get on the barrel. I had assumed a 1:8, but want to make sure that will still shoot well at the 100 yard if I use the heavier bullets (105s for example).
The match shoots at 100 yards, then moves to 300, 350, 400, 450, 500 and then 600. I had assumed something like the 105 Berger VLDs would be good for it, but am worried about the 100 yard shots. Would you load 2 different bullets for the match? If so, how much lighter would you go?

For some basic twist recommendations see the Berger Quick Reference Guide. For sure you need an 8 twist, but possibly faster for the long distance. Berger says the 105 Hybrid needs a 7 twist, as well as the 115 grain. What I would recommend is using the Berger Twist Rate Calculator, and enter those particular bullets along with your specifics, such as expected muzzle velocity, altitude, & temperature, and a twist rate (try 7, 7.5, & 8). What you might find is that you only have a slight loss in stability and slight degradation of BC with a 8, or if you are going with a custom barrel you may be able to select a 7.5 twist.

In any case you have to have a fast twist for the distance, and a long throat for the long bullets. And you will have to live with the impact of that at short distance like 100. In general flat base bullets tend to be more accurate at short distances. I have a 6BR in 12 twist that unfortunately has a long throat for long bullets than I cannot shoot. What I have found is that you need to find flat base bullets with a long base to ogive length, or you do not have enough neck in the case to seat them. In my case, I have found the 68 grain Berger Target bullets to be the most accurate, with Bart's Ultra 68 grain a close second. The 80 grain Berger Varmint flat base is OK, but clearly not as good as the 68 grain target. I would try all three of those for your 100 yard. Once you go to 300, your 600 yard long heavy bullets are probably going to be as good as any. Not sure there is a case to be made for an intermediate bullet weight for 300 or 350. Possibly the 95 grain VLD might make sense to test. Won't change the way you build the rifle though.

 

[HTSmith]

My suggestion would be a 7.5" twist and shoot the 105 class bullets at all the distances. You might be surprised at how well it does at 100 yards. Keep the sight adjustments simple.

 

[cjrowe]

A 1:8 twist will stabilize any 105/107 bullet, including the Hybrid, in a 30" barrel. They are extremely accurate out to 1000 yards. No need for a faster twist for that weight class.

 

[Mulligan]

A 1:8 twist will stabilize any 105/107 bullet, including the Hybrid, in a 30" barrel. They are extremely accurate out to 1000 yards. No need for a faster twist for that weight class.

^^^^^^^^^^^^^
Exactly!

 

[Mozella]

A 1:8 twist will stabilize any 105/107 bullet, including the Hybrid, in a 30" barrel. They are extremely accurate out to 1000 yards. No need for a faster twist for that weight class.

I don't shoot 1000yd matches, but I usually achieve either smallest group or best score at my local 600 yd BR matches with my 6mm BR Norma launching 105gr Berger Hybrids or 105gr VLD's from my 28" Shilen 1:8 twist barrel.

 

[MarkS]

I am building a new 6BR rifle (on a Rem700 action). There are so many variables with this cartridge!

Mostly, I will be shooting a 100-600 yard match (prone). I am trying to figure out what twist rate to get on the barrel. I had assumed a 1:8, but want to make sure that will still shoot well at the 100 yard if I use the heavier bullets (105s for example).

The match shoots at 100 yards, then moves to 300, 350, 400, 450, 500 and then 600. I had assumed something like the 105 Berger VLDs would be good for it, but am worried about the 100 yard shots. Would you load 2 different bullets for the match? If so, how much lighter would you go?

But the first important question is the barrel twist. Probably going with a Heavy Varmint taper on a SS barrel that is at least 31" as a blank.

jloehle,

I do not pay for extra long barrels, i just tell the smith to leave it as long as he can. I have a 28" CBI barrel on my Savage, it was in stock. 8 tw is best. Be sure to get the firing pin bushed on your Rem 700, if not your will get primer cratering before get to high pressure.

Mark Schronce

 

[Shynloco]

A 1:8 twist will stabilize any 105/107 bullet, including the Hybrid, in a 30" barrel. They are extremely accurate out to 1000 yards. No need for a faster twist for that weight class.

Yep! Yep! For short 100 yd shooting, I use Bart 68gr Ultra which shoot easily in the 1's or even 2's when I'm having an off day. But those 105/107 Hybrids at 600yds to 1K shoot extremely well. So say use the 8 twist on the long barrel, not to mention the smart suggestion by dk.

Alex

 

[stacy]

MY 6BR 30'' BARREL 1/8 SHOOTS 87VLDH AND 105VLDH OUTSTANDING IT NEVER DID SHOOT THE HYBRID WELL WITH N-540

 

[noload]

1 in 8 twist with 104FB, and shoot any bullet you want.

 

[Sniper338]

My 6br hammers at 100 yards easily. 8 twist 105 berger vld, varget

 

[comagutsa]

i just got built my 6BRX and went with 1;7.5 twist just to make sure it will be fine with hybrids as per bergers twist rate recommendations, what have you got to lose
your building a new gun get the better twist berger recommend,
yes i shot 105gr hybrids in my 1;8 twist 6BR with good results but 1;7.5 twist is looking like its working better already at 100m and 500m/547y