Barrel Length Recommendations

[Brians356]

Most start out trying to prove the authors pre-conceived opinion.

Just curious, how could someone jigger such a simple test to produce a desired pre-conceived outcome?

In the case of the 6.5 Creedmore 142-gr test, they used a charge of H4350 exceeding the published maximum listed by Hodgdon, a powder second only to H100V for top velocity in their data, and the second-slowest powder tested. They chose poorly if they were trying to cherry pick powders.

Simple physics states that increasing barrel length will reach the point of negative return in velocity. It's been well documented that all the powder that will burn has burned within the the first foot of barrel, even for the slowest rifle powders we use. It's only a matter of residual gas expansion petering out enough for friction to become dominant. You're implying that cannot happen in any barrel less than, what, 30 inches long, so therefore the test must have been rigged?
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[tenring]

This hits home with me. I just put a 25" Brux 1.200" straight tube barrel on my 6BR match Rem 700. Put my NF 12-42 on it and the scales show the rig weighs 17.5+ lbs. Way too muzzle heavy and I would struggle getting it to the line. Took it back to the smith yesterday. He checked some tables and concluded I would lose about 11 oz per inch. I am having him cut it back to 23.5" . With an 1.5inch removed, I lose just a pound. For short range BR, I will lose maybe 60 fps.

 

[spife7980]

Just curious, how could someone jigger such a simple test to produce a desired pre-conceived outcome?

Maybe not jiggered but flawed in some way.

What I find so interesting is how slow their velocities (max of 2683) are compared to what is commonly reported (2750-2850) everywhere I read.

 

[Brians356]

This hits home with me. I just put a 25" Brux 1.200" straight tube barrel on my 6BR match Rem 700. Put my NF 12-42 on it and the scales show the rig weighs 17.5+ lbs. Way too muzzle heavy and I would struggle getting it to the line. Took it back to the smith yesterday. He checked some tables and concluded I would lose about 11 oz per inch. I am having him cut it back to 23.5" . With an 1.5inch removed, I lose just a pound. For short range BR, I will lose maybe 60 fps.

Given that 6 BR holds a lot less powder than Creedmore, you might not lose any velocity going down from 25 to 23.5 unless you're shooting light bullets, although your bore is a lot smaller. But you might clock a typical load before you cut the barrel, and again after, and report the difference back here.
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[Brians356]

Maybe not jiggered but flawed in some way.

Can you think of a way they could have bollixed such a simple test? I can't, it's a serious question. (I've already discounted the notion of inappropriate powder selection, and low charge weight.)

What I find so interesting is how slow their velocities (max of 2683) are compared to what is commonly reported (2750-2850) everywhere I read.

Fair enough. But their load is already running a bit faster than Hodgdon's max for H4350, and they'd have to run their H4350 load a whole lot hotter to extend bullet acceleration another 4 inches. (FWIW Hodgdon's H100V max load runs 2737.)
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[mikegaiz]

Don't forget to figure in powder burn rate into barrel Length/velocity story.

 

[Brians356]

Don't forget to figure in powder burn rate into barrel Length/velocity story.

If that's addressed to me, I touched on burn rate. One way to fudge such a test would be to choose one of the fastest powders published for the cartridge in question, and burn as little of it as possible. Such was not the choice in the 6.5 Creedmore test at issue here, where one of the two slowest appropriate powders, at above published max charge, was employed.
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[mikegaiz]

If that's addressed to me, I touched on burn rate. One way to fudge such a test would be to choose one of the fastest powders published for the cartridge in question, and burn as little of it as possible. Such was not the choice in the 6.5 Creedmore test at issue here, where one of the two slowest appropriate powders, at above published max charge, was employed.
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Not aimed at you, just a factor in the discussion.

 

[hogan]

Looking for "best" precision?

Might just want to go 20-22". Look at what the benchresters use. barrel whip, wave resonation, transit time are all minimized with a shorter barrel. 36" barrel, or 40+ inches might get you hellacious velocity gains, but... yin/yang... I recall reading that 21.75" was about optimum barrel length with a match contour.

 

[Brians356]

I recall reading that 21.75" was about optimum barrel length with a match contour.

That's Virgil King's ("Secrets Of The Houston Warehouse") magic barrel length.

http://www.angelfire.com/ma3/max357/houston.html
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[Richard Coody]

That's Virgil King's ("Secrets Of The Houston Warehouse") magic barrel length.

http://www.angelfire.com/ma3/max357/houston.html
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perfect for 6PPC at 100 yards

again I ask if short barrels are better then why do the long range shooters shoot long barrels?

Surely you don't believe they don't know what they are doing. 1.5 inch 5 shot group at 1000 yrds. 3" groups pretty common. barrels 28" and longer.

 

[Brians356]

again I ask if short barrels are better then why do the long range shooters shoot long barrels?

Surely you don't believe they don't know what they are doing. 1.5 inch 5 shot group at 1000 yrds. 3" groups pretty common. barrels 28" and longer.

There are several flaws in your logic. For one, you resort to the argumentum ad verecundiam ("appeal to authority") fallacy. It's akin to saying "97% of climate scientists agree that primarily mankind is warming the planet, therefore it must be true." **

Also, your assertion postulates that 100% of the long-range BR competitors everywhere shoot long barrels (there are almost certainly at least a few who do not, and with some success).

But, more critically, it postulates that essentially all long-range shooters have actually evaluated, and rejected as inferior, a 21.75" barrel. It's very likely (given the herd mentality endemic in benchrest shooting) that few of them has even bothered to try a short barrel.

I'm not saying a short barrel is better than a long one in long-range competition. I'm just pointing out that the scarcity of short barrels doesn't ipso facto prove they're inferior. I suppose if you're shooting a cartridge with enough powder capacity to take advantage of it, and if only very high muzzle velocity can be competitive, maybe a 30-inch barrel is needed to eke out those last 75 fps.

Is top velocity the main component of long-range success in your opinion? Can modest cartridges like 6.5 Creedmore not compete at 1000 yards? (These are honest questions.)

[** Even if 97% of climate scientist really do agree (they don't, actually) that mere fact alone doesn't validate the hypothesis of AGW. That's not the way real science works. In fact, telling any real scientist that there exists near total consensus that a chaotic, multivariate non-linear system as vast and complex as global climate is not only well understood but is actually predictable, decades out, would (behind closed doors, anyway) elicit paroxysms of laughter.]
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[Joe R]

Ok Guys,
I know everyone is probably tired of hearing about barrel length, but I'm looking for recommendations for a (260 Remington) SA Bolt Action rifle that I'm having re-barreled. Not to confuse anyone, this rifle has been 6.5BR that I just haven't been pleased with so I'm changing the caliber to a 260 Remington, a caliber I am unfamiliar with (experience shooting that is).

So here's the deal...I just bought a new Kreiger 1:8.5 Match Stainless 4 groove 1.250 straight barrel (for a wider range of bullet weight). I've noted that the loads recommended in both the Sierra & Hornady Reloading Manuals were tested in a 24" barrel. Berger does not state what barrel length they used in their test rifle. I am well aware that longer barrels only provide a few FPS increase in velocity. I shoot exclusively 100 - 200 yds and am unsure whether a 28-29 inch barrel would provide any benefit. But I need some EXPERT and EXPERIENCED suggestions from those who've shot a 260 Remington bolt gun in competition or for best accuracy, which is my goal (the best accuracy part). Any advice would be appreciated and thanks for indulging me.

Alex

Alex,
You asked for someone who has been shooting a 260 in competition and I have (F-Class) on and off for the past year. I have had excellent results with a 30" Bartlein 5R 8 twist shooting the Berger 140 grain hybrids. You can read all about it in this thread http://forum.accurateshooter.com/threads/my-new-260-ai-build.3909184/

IMO opinion the 260 is the best caliber I've ever used. Easy on recoil, crazy accurate and easy to tune. It will give up nothing to the Dashers or the 6.5x284. But has longer barrel life. Mine has 1,420 and is still shooting like a laser for me. Alas, for 1K yards the 7mm have better wind resistance. But for mid-range IMO you can't do better.

Kindest regards,

Joe

 

[ShootDots]

Alex,
You asked for someone who has been shooting a 260 in competition and I have (F-Class) on and off for the past year. I have had excellent results with a 30" Bartlein 5R 8 twist shooting the Berger 140 grain hybrids. You can read all about it in this thread http://forum.accurateshooter.com/threads/my-new-260-ai-build.3909184/

IMO opinion the 260 is the best caliber I've ever used. Easy on recoil, crazy accurate and easy to tune. It will give up nothing to the Dashers or the 6.5x284. But has longer barrel life. Mine has 1,420 and is still shooting like a laser for me. Alas, for 1K yards the 7mm have better wind resistance. But for mid-range IMO you can't do better.

Kindest regards,

Joe

Joe is absolutely right! The .260A.I. is, at least in my humble opinion, just as accurate as a Dasher. The obvious ballistic advantage can not be argued, neither can the "controllability" of the rifle. I believe it is a very decent 1000 yard F-Open cartridge and for Mid-Range, 600 and under, you simply can not equal it. The BIG 7's may shoot a 600 score at 300 or 600 yards but so will a .260A.I. and 6 out of 10 times will "out X" the 7's.. It is the finest Mid-Range cartridge I have ever seen and I have seen MANY of them!

 

[Richard Coody]

There are several flaws in your logic. For one, you resort to the argumentum ad verecundiam ("appeal to authority") fallacy. It's akin to saying "97% of climate scientists agree that primarily mankind is warming the planet, therefore it must be true." **

Also, your assertion postulates that 100% of the long-range BR competitors everywhere shoot long barrels (there are almost certainly at least a few who do not, and with some success).

But, more critically, it postulates that essentially all long-range shooters have actually evaluated, and rejected as inferior, a 21.75" barrel. It's very likely (given the herd mentality endemic in benchrest shooting) that few of them has even bothered to try a short barrel.

I'm not saying a short barrel is better than a long one in long-range competition. I'm just pointing out that the scarcity of short barrels doesn't ipso facto prove they're inferior. I suppose if you're shooting a cartridge with enough powder capacity to take advantage of it, and if only very high muzzle velocity can be competitive, maybe a 30-inch barrel is needed to eke out those last 75 fps.

Is top velocity the main component of long-range success in your opinion? Can modest cartridges like 6.5 Creedmore not compete at 1000 yards? (These are honest questions.)

[** Even if 97% of climate scientist really did agree (they don't, actually) that mere fact alone doesn't validate the hypothesis of AGW. That's not the way real science works. In fact, telling any real scientist that there exists near total consensus that a chaotic, multivariate system as vast and complex as global climate is not only well understood but is actually predictable, decades out, would (behind closed doors, anyway) elicit paroxysms of laughter.]
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I am simply asking a question. Why do long range shooters shoot long barrels?

 

[dreever]

Ok Guys,
I know everyone is probably tired of hearing about barrel length, but I'm looking for recommendations for a (260 Remington) SA Bolt Action rifle that I'm having re-barreled. Not to confuse anyone, this rifle has been 6.5BR that I just haven't been pleased with so I'm changing the caliber to a 260 Remington, a caliber I am unfamiliar with (experience shooting that is).

So here's the deal...I just bought a new Kreiger 1:8.5 Match Stainless 4 groove 1.250 straight barrel (for a wider range of bullet weight). I've noted that the loads recommended in both the Sierra & Hornady Reloading Manuals were tested in a 24" barrel. Berger does not state what barrel length they used in their test rifle. I am well aware that longer barrels only provide a few FPS increase in velocity. I shoot exclusively 100 - 200 yds and am unsure whether a 28-29 inch barrel would provide any benefit. But I need some EXPERT and EXPERIENCED suggestions from those who've shot a 260 Remington bolt gun in competition or for best accuracy, which is my goal (the best accuracy part). Any advice would be appreciated and thanks for indulging me.

Alex

I limit my barrels to 26 inches. Longer barrels to me are unwieldy, and 26 inches fit nicely into my gun safe.

 

[ShootDots]

You're probably onto something there, but Joe R shoots a plain unadorned 260 Remington unless I'm inexplicably mistaken.
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He shoots a .260A.I.>>> He used my reamer...

 

[Brians356]

He shoots a .260A.I.>>> He used my reamer...

Oh. Well, then, what's inexplicable is why Joe calls it simply "260", especially when the OP asked about barrel length for his "260 Remington".
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[spife7980]

I am simply asking a question. Why do long range shooters shoot long barrels?

Because you get more velocity while being able to go easier on your brass. More velocity means that there is less time for the wind to push it off course.
All within reason of course.

 

[Brians356]

Because you get more velocity.

What's the smallest-capacity cartridge that seems competitive in long-range matches?
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