what twist and barrel length for 100-500yds with a 6br?

[GSRswapandslow]

I'm planning out my next gun build...and have settled on a 6br, and am wanting to get some advice on twist rate, barrel length, and also bullet weight.

1. I am NOT a competition shooter....shooting is a hobby and will never be more than that....so I have no need to have the best of the best of the best....just saying

2. most of my shooting (90% or more) will be at my family's range. There is only 200 yards, and the shooting will be done via a bench...with a rear bag and rest.

3. SOME shooting will be done up to, currently, 400 yards...but I'm hoping to be able to stretch that to at least 500 yards if I can do some real looking around. This is at my brother-in-law's tree farm in Bland, VA....so moutains/hills...but lots of open ground. Currently only shoot my .223 and .22lr's up there and have been shooting prone....I intend to build a portable bench though.

My proposed setup is:
Savage target action...i guess just RBRP...really never shot any other configuration
Tooley MBR stock from Shehane since he's local...I read he was going to be doing the savage actions..
Protector rear bag...or whatever he recommends that's cheaper than an Eastwood...(hell...i'll prob buy the eastwood...)
Cowan or modded Rock BR rest
Seekins or TSR rings (i have both...i like the seekins better, but they're just too damned bulky)
EGW rail
I'm undecided on a scope...but maybe a fixed power Sightron, Weaver, or Luey....just depends on the funds as this will be the last purchase.


I was thinking something along the lines of a 28" prefit in a full 1" bull.....maybe 26" or 30"....if one would benefit me more....but I have no clue on what twist rate.... Should I just go with an 8" so I can shoot the 105 amax's and 105 bthp hornady's.....or go slower and focus on the 75 and 87gr Hornady bullets?

 

[Nomad47]

If you are SURE you will NEVER go beyond 500 yards, a 10 twist is probably a good choice as you can shoot anything up to about 95 grains.

But personally, I favor the 8 twist. You can shoot the 87s in that twist as well as heavier bullets. I have a Savage Target action 8 twist 1" bull barrel 28" long. I just shot a groundhog today at 24 yards. Two weeks ago, I shot one at 1062 yards. 105 AMax bullets. How's that for versatility? I also recently shot two three shot groups at steel at 500 yards from a portable bench. Both groups measured 1.25" or .25 MOA.
And the 6BR is considered a more accurate cartridge, although a bit slower than the 6XC.

 

[xswanted]

I built a Dasher with a 26" barrel, 8 twist.

Shoots very good and I'm in the same boat you are. Gun isn't crazy heavy and its a blast to shoot.

 

[fdshuster]

You can't go wrong with an 8 twist. I used to think an 8 twist with the 105/ 108 gr. bullets would not work at the closer distances, but lately have been proving (to myself) that if you have the right combination, they can be every bit as good as a 14 twist with lighter bullets.

One of my best, most consistant loads in one of my 8 twists is 30 grs. of Varget, with the 105 Bergers (#24428), seated to touch with the CCIBR4 primers. In my rifle, ( don't know about any others), it will just flat out shoot. 6BR chamber cut with my reamer, .269" no turn neck, Krieger 24" heavy varmint contour.

 

[GSRswapandslow]

i know the trend is to go with the heavies....same for every caliber it seems like these days, but like I said....never over 500yds. If i ever DO find that I can shoot farther than that....i'll build something off of a 7mm for the super high bc. But, would it hurt me at 100/200yds? I mean, i'm not really looking for one tiny little hole.... a .2 or .3" groups would be spectacular to me! 1:8 just seems really easy to get...

 

[rayporter]

the 8 t will not hurt you for what you want at 200y.

i shoot a 58 custom carpenter bullet at 4000 and at 100y they will shoot a .3 easy. and this is in 3 different barrels that have an 8 twist. 55 noslers will do almost as good too.

 

[fdshuster]

GSBswapandslow: In your original posting, there was mention made ( item 3) of possible 4 & 500 yard distances, so with that in mind I recommended an 8 twist.

Now you seem to be leaning toward shorter distance only & if that's true, then the recommendation would be for a slower twist with lighter weight bullets.

With a fast twist any internal defects that the bullet may have will show up sooner with a fast twist than a slow twist barrel. Also if you're using bullets with thinner than normal jackets & pushing them at the maximum velocities, they may come apart somewhere between the muzzle and the target. Not saying they will, just that there is a grerater chance.

 

[GSRswapandslow]

the vast majority of my shooting is at 100 and 200 yards. I have access to a private range (covered, level, cement benches on a thick cement foundation...a family member built it with the help of several other shooters...it's pretty legit to be on some of his land) and I have backers at the berms at 50yds, 100yds, and 200yds.... I haven't bought a rest yet, but will very soon.

The 400-500yd shots will be at a family member's tree farm in Bland, VA....and as of right now we've only shot out to 382yds prone, but there's already a 400yd (dead on 400yds at that) shot setup...just have to build a portable bench to shoot from...but that's also a 2.5 hour ride...and I can't shoot when the grass is high...so that's going to be limited.

I have some coworkers claiming 500, 600, 800, 1000, and 1500yds.....but I've yet to see them actually invite my to come shoot...so I'm not even considering that into the equation.


So, after some reading and talking to folks...and you helpful folks here and through pm's....i've decided to just do this:
Savage RBLP target action
keep the savage trigger that comes with the action...my best friend has an LRP with the stock trigger and it's good enough for this gun
6mm BR chamber...have to find out the neck and freebore though..
28" CBI pre-fit (it's a kreiger barrel, just button rifled instead of cut) in the bull contour
EGW HD base
Seekins Rings (unless some of the sets i have on hand fit)

The few things left to decide:
I THINK i still want to get the Tooley MBR style stock from Bill, I really have to call him next week to see if they're out.....

and I'm going to get put on the list for the Cowan rest

and Lastly...i THINK i'm going to go with a Sightron Sii Big Sky 36x scope....unless i can find something used for a good deal

 

[MarkS]

GSRswapandslow

Sounds like you need a 12tw. You can shoot 55 gr to the 87Vmax. The 68gr or 80gr benchrest would be great for the target shooting. All the barrel you need is 26", but if you want a longer barrel go for it. The CBI are great. MBR stock work for me. I have had many stocks and like the MBR best. I have had the 36 Weaver and Sigtron. They are good scopes, but don't do well in low light. I would look at the 24X or a good variable scope. I have a Sightron SIII 8 x 32 that I like alot. If later you need an 8tw they are around $300. I have 3 barrels for my Savage.

Good luck on the build
Mark Schronce

 

[GSRswapandslow]

my best friend has the 8-32 mil/mil....i haven't really gotten a chance to check his out, but i will this weekend I hope.

I was just looking at the 36x since it's cheap....might just save up $200 more for the 8-32 though

 

[Phil]

I have a 14/12 and a 7.83 twist in 6 Dasher using 55/87 and 115 bullets respectively.

My advice would be to choose a bullet,better yet,a weight range of bullets(87-95 for example) then twist accordingly.

Lengths are from 28 to 31 inches,i don`t think it makes a hill of beans in difference though...

Phil.

 

[GSRswapandslow]

well...like i said, i'd like to try the 2 87gr models and the 2 105gr models....i really don't know which would be better, so I'll just do the 1:8 since it'll shoot both....and that seems to be what the CBI comes in anways

 

[Sully2]

I have a 1:8 twist in a Varmint taper contour of "about" 27 inches. So far shoots60gr Sierra's and 105 Boatail Hornadys fine..??

 

[GSPV]

If you can find one, a 10 twist would be a nice compromise. The Berger 87 VLD Hunting with Varget would be great. I have been using 8208 XBR. I just like how it meters through my ChargeMaster. 30.5 grains isn't super hot and shoots great.

 

[amamnn]

I shoot a 6BR Shilen select match 1/14 ratchet twist in a 26" length. I was so happy with that barrel I bought another one to install next year when this one finally falls off in accuracy. At 200 yards, using 65 or 66 grain bullets and N-135 powder, the rifle will shoot in the .2 MOA all day long if I do my part. These days, I shoot mainly for fun and some experimentation at 200 yards only using this rifle.

As someone has mentioned, there is no good reason to go heavier and spin faster at this range and application, but there are good reasons to go lighter/slower. I have tried 1/10 twists and heavier bullets in two 6mm barrels and as far as I can see, that twist is a compromise that gets the worst of both worlds, at least when shooting for best accuracy off the bench at 200 yards. Lighter bullets cost less money, too.

I have shot both the regular Shilen rifling and now the ratchet. I don't really notice much difference on target between the two, with one exception. It seems I can shoot a bit longer--something like one more relay if shooting a 10 shot target, before I feel that accuracy is impaired and a cleaning is needed. So I can now expect 3 targets and maybe 3 sighters for each target, when before I was only going 2 before cleaning.

 

[tiny68]

I have a 30" Krieger 1:10 6BR barrel for one of my target actions. I shoots the 95 BIBs very well at 100-500 yds. It also shots the 95 Berger VLD very well even thought it shouldn't according to the Greenhill formula. Walt told me some 1:10s will and some will not stabilize the 95 VLD. Mine does. I like that bullet up out to 500 yds. Below is a report of the speeds I could get with the 95 BIBs.

http://forum.accurateshooter.com/index.php?topic=3205403.msg31143078#msg31143078

Luck, Tiny

 

[soldierofchrist]

I have a 1 in 12" twist and I love it. I do a lot of varmint shooting and being able to shoot bullets from 55 grains all the way up to 80 grains works well for me. If your only shooting up to 500 yards you will find that a 55 grain Nosler clocking in at 3800+ fps will have a lot flatter trajectory out to that range then the 105 grain bullets if you don't want to adjust for elevation as much. If you ever want to use your 6 BR for long range or big game hunting I would go with the 1 in 8" twist so you can stabilize the bullets that are intended for that purpose. The 1 in 12" is in my opinion the best choice for Varminting.