Barrel length??

[jerrschmitt]

Spent the morning with my local Gunsmith designing my new long range (1000 yd) Prairie Dog rifle. It will be a 6BR 8Twist on a trued 700 action that I already own. I thought a 28 inch or so barrel would be about right but he says to go with a 24 inch. His idea is that it will be easier on the bedding with the shorter barrel due to the shorter lever length and the slight loss in velocity won't matter. Any thoughts?

 

[X Ring Accuracy]

The longer the better in my opinion. If he thinks 28 is too long, ask for a 3 point bedding. It means another bedding "block"just in front of (toward the muzzle) the recoil lug. Some say its old school, I just know it works on long barrels. Just my .02

 

[sxsboy]

I hang out a NW Armswerks quite a bit and Bret has been playing around with determining barrel length using "Quick Loads" and inputing the load data the shooter wants to shoot,. ie: Bullet, Weight, Powder Chrg etc and have been amazed at what it will tell you about about burn rate vs barrel length. Bret likes it to be about 98-99%. With some loads that happens in 22 or 24 inches other times it's 28 or 30. Just something to think about.

 

[RJinTexas]

If it's for long range and you stated your building a 1000yd P-dog rifle, I'd not go any shorter then 28" minimum length. I've owned several 6mm in various calibers in lengths from 24" to 30". I've found that 28" barrels especially with a 6mmBR give a little more speed which helps greatly in the winds I encounter in the dog towns. The longer tight twist barrels usually shoot the heavier bullets much better, just look at what there're shooting in 600yd and longer competition. I've been shooting long range p-dogs for ten years and I've never found any of my heavy 1.300 dia full bull 29" Shilen barrels to ever degrade the bedding, most of my rifles are switch barrels and the actions get removed from the stocks on a regular basis, if your bedding was properly done it shouldn't be a issue. There's nothing wrong with listening to your smith's advice but remember your the one building the rifle, he works for you. I've never heard of a qualified smith recommend that you stay with a shorter barrel to insure a quality comptent bedding job. Good luck with your build.

Regards
RJ

 

[WayneShaw]

What is the reason for a long barrel in long range applications? Speed!

So where does the extra length become a benefit? Burning slow burning powder down the barrel.

Using a 6BR as the cartridge, which is fine, I don't believe you will see a great benefit in a real long barrel, because there just isn't that much powder to burn through. If it were a 6 ACK, or 243 ACK, that would be different.

The longer the barrel, the more barrel vibrations and whip to deal with. So there must be a balance.

26" tops. My opinion.

 

[cmillard]

26-28 tops. you would only gain about single digits per inch after that.

 

[SS427]

If I was truly shooting 1,000 yards, I would want the longer barrel and extra velocity, provided I wouldn't have to pack it very far. 28 inches would be max though, as I think most all the powder would be burned in that length.

On the other hand if I wanted to be mobile I would give up the velocity and build a better balancing gun with a 26 or even a 24 inch barrel. Perhaps that is part of the gunsmith's thinking.

 

[Steve Blair]

Burning all the powder within the barrel length is a good practice but does not mean that no further bullet acceleration takes place after burning is complete. While residual barrel pressure is greater than bore friction, the bullet will accelerate.

The point of long barrels is not the 35-40 fps ballistic difference between 28 and 30 inches (with 107 Sierras in 6BR and RL17). The point is to reach a higher accuracy "null" point or "node" where the rifle shoots exceptionally well. Not all rifles display this but it occurs often enough with common component combinations that competitors try to reach them.

Some shooters feel that the lower muzzle pressure in longer barrels produces less bullet buffeting as the propellant gases briefly overtake the bullet. Rimfire shooters use long barrels to slow the bullet, ensure that it remains subsonic and reduce muzzle pressure.

 

[alf]

Part of the equation is what barrel contour, bench gun only or some carry, and what stock are you using, as in the forend length and material, and balance, as in not getting too nose heavy. If it's going in, say a ST-1000 or a PSS, their forends are a couple of inches longer than "normal", and are on the "heavy" side. Maybe add some lead to the butt, and run a 28" heavy varmint contour. More to it than just "what bbl. length".