6 mm BR barrel length why so damn long

Codiekfx400

Codiekfx400

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Jan 29, 2018
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#1
Somebody school me on 6 br barrel length. Such a small amount of powder being burned why is there a need for a 26" pipe. I would think this would be of similar characteristics as a 223 Rem where a 22" or 24" barrel is good enough for getting to near max velocity for that small amount of powder.
 
#3
Codiekfx400 said:
Somebody school me on 6 br barrel length. Such a small amount of powder being burned why is there a need for a 26" pipe. I would think this would be of similar characteristics as a 223 Rem where a 22" or 24" barrel is good enough for getting to near max velocity for that small amount of powder.
Click to expand...

Hmmm, I have a 30 inch barrel on my .223 :)
 
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#6
I was thinking a 22" or 24" barrel would be sufficient but I don't want to sacrifice much velocity. If a 26" barrel gets me 3000 fps with a 95 grain bullet what would a 22" and 24" barrel give me with the same exact load.
 
#8
It is free velocity and more efficient. If you want a short barrel that gets 3000fps pick a different caliber, you will never be happy with it. 6br is not a fast cartridge and never will be. 6BR is a 600y benchrest cartridge . It has great accuracy and good barrel life. You must have read Josh Kunz post about 95 at 3000fps. Don't buy into that shit. You want to go fast get a 6x47 or 6Creed.
 
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#11
In a chamber like 6BR velocity loss won't be as significant per inch as higher capacity rounds but you're still going to get more velocity with a longer barrel. As mentioned it's free performance with no additional wear on the throat for the same charge. It's just a question of whether that performance is worth it to you.

I'm assuming you're considering this for a match rifle since you're jumping on the BR bandwagon and IMO weight is your friend whether it comes from barrel length, profile, or both. So the longer barrel gives you more velocity as well as more stable to shoot. The added length has never made any sort of a difference to me unless your hanging a suppressor too and then it can get a little unwieldy but still plenty manageable.

My 6BR will wear a 26-28" MTU or M24 1:7.5T barrel with a brake.
 
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#12
Codiekfx400 said:
You mind sharing your rifle specs and load data?
Click to expand...

Haven't worked up a load for it yet, it's a Savage Long Range Precision action with an F class take off barrel. I've been shooting IMI 77 smk's, one hole up close if I do my part, 2950 fps gets me to 1K no problem. Don't see you getting 3K fps with 95's.
 
#14
I wouldn't say the 6BR couldn't go fast. Too many guys corner a cartridge into a certain niche without looking at the whole spectrum. My personal 6BR is set up for varmint hunting, twisted 1:14" and runs the 55 grain NBT at 3920 fps and here is S. Texas has proven to be not just absolutely pin point accurate, easy to shoot, and is a sure enough killer....

Oops, my barrel is a Hart and it's 26" long. Smithed by Dan Dowling.
 
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#15
IMO, a 26" barrel is what most would consider normal in length for our kind of comps.

Just for info's sake I used to run 105 JLK's in my 30" 8 twist 6BR at 2940 fps, it was a medium load.

After using 95gr SMK's in my 6mmFatRat for a year at 2870 fps I think they do great out to 700Y or so and only loose .2 mil of wind at 1000Y, but they do recoil less and can be driven around 100 fps faster than the 105's.

My 6x47L barrel is about used up, I think I'll try 6mmBR in a prefit to see how it feeds and also see if I can overcome the extra wind drift, as well as enjoying longer barrel life. Maybe even have it set back and redone to 6BRA later on.

Did you guys know a new 600Y benchrest record was set with the 6BRA, .282"!
 
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#17
steve123 said:
Did you guys know a new 600Y benchrest record was set with the 6BRA, .282"!
Click to expand...

Un-freaking-believable. You have to see the 600 yard target to imagine how small that truly is. Most guys here would be posting up that 5 shot group and bragging if they shot it at 100 yards.

q4EhaBt.jpg


As a side note, my little 6BRA has been treating me pretty good. Pulled a top ten in the Rock Lake PRS match last weekend with it. 105 hybrids at 2950 from a 26" barrel with 31.4gr of Varget.
 
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#18
I was just about to ask this question as I'm debating 24/26' for BR barrel length. Pretty amazing what this little cartridge will do with 30 grans of powder - my .243 is a laser but it eats 48.5gr of H1000 per shot for 3100fps+ with 105's - if I can get 2850fps with the BR it's nearly a free lunch on ballistics with all the upsides of reduced recoil and barrel ware.
 
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#21
Sheldon N said:
Un-freaking-believable. You have to see the 600 yard target to imagine how small that truly is. Most guys here would be posting up that 5 shot group and bragging if they shot it at 100 yards.

q4EhaBt.jpg


As a side note, my little 6BRA has been treating me pretty good. Pulled a top ten in the Rock Lake PRS match last weekend with it. 105 hybrids at 2950 from a 26" barrel with 31.4gr of Varget.
Click to expand...

If I get into a 6mm it will be the BRA.
 
#23
velocity just aids in environmental condition/dope reading, as long as you get the bullet into a good accuracy node.
what i have found with the PRS craze is guys constantly trying to hot rod a round instead of using the right tool for the right job.
if the benchrest guys (used to be one of them a long time ago), though a 26" barrel being pushed hard was more accurate we would have jumped in and ran. we could have balanced the rifles and rode the bags better.
 
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#24
It's clear why a 26' tube makes sense if one is trying to extract maximum performance from the BR - but since I'm not really a 'gamer' I'm happy to cede some performance in favour of 'fun' - with this in mind can anyone comment on what is possible with a 20-22' 6BR, Varget/105gr combo? Thanks
 
#26
On barrel #1, started at 32.3 gr. of varget and ended at 32.6
Barrel 2 is 32.5 gr. Varget.
105 hybrids .005" off the lands for both
Around 2950 for both.
 
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#31
Dropped my Tikka.243 off at the Smith to have a new barrel spun up in 6br. Going to run this as a switch barrel so the.243 will be kept for the longer stuff. Here in Australia we tend to shoot clearly defined short, medium and long range matches - with the 'shorts' usually 400m (occasionally 500m) max range. For this the BR seems perfect. I opted for a 21.5 inch barrel (to keep weight around the 13-13.4lb range on this build) and have got some PVA kits coming. Plenty of varget and 105gr Hybrids on hand so will report back on accuracy nodes - will be happy with 2725-2750fps
 
#34
A buddy of mine shooting F-class tries to talk me into 28" barrel in 6mmBR. It's so long. I was thinking rather 26". My maximum range will be 800m. I would happily avoid the 28" cannon.
 
#35
2 dogs said:
I wouldn't say the 6BR couldn't go fast. Too many guys corner a cartridge into a certain niche without looking at the whole spectrum. My personal 6BR is set up for varmint hunting, twisted 1:14" and runs the 55 grain NBT at 3920 fps and here is S. Texas has proven to be not just absolutely pin point accurate, easy to shoot, and is a sure enough killer....

Oops, my barrel is a Hart and it's 26" long. Smithed by Dan Dowling.
Click to expand...

21-3/4" 1-14 twist Shilen on one of mine.
I run 33.5gr AA-2230c under a 65 or 68 gr bullet for 3450-ish.
35.5 gives me 3540fps but it's a little warm so I keep it at the lower velocity.

I run the same powder and charge on a shorter throated 22" 1-14t 6-BR and normally shoot the 58 or 65 V-Max. I can swap projectiles and keep the same POI at 100.

I have never Chronograph tested the second rifle, so I have no idea how fast the 58s move.

The next barrel will be a fast twist and I'll have it finished 24 or 26" and I won't worry if I did the right thing.
 
#44
I'll post to keep this thread near the top. The br and bra will always hold a spot in my gun safe but you won't see any of them with a barrel longer than 24". 29.9gr of varget and 105s gets me to 2800 and that's plenty fast for this fudd. If I really want to speed things up I'll shoot 55s at 3650fps.
 
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