Barrel thickness heat and rigidity.

greg11

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Just wondering if some of you guys can comment on this quote from an article I was reading:
Many shooters don't understand the main reason long-barreled varmint rifles are fat is not to absorb heat--it's to make them stiff. Hence the increasing popularity these days of shorter, lighter "walking varmint rifles." Shooters are finally waking up to the fact that a good short, slim barrel is just as accurate as a long, fat barrel and a whole lot easier to pack around. I first realized all this in a moment of amazed delight about 25 years ago, the first time I ever fired a 15-inch box-stock Remington XP-100 pistol chambered for 7mmBR at a 200-meter target.

Three shots went 5/8 inch. My best varmint rifle was not that good with my best handloads. After a patient design engineer explained to me what was going on, I became an instant believer in short-barrel ballistics. That's probably why I went on to spend two decades as Shooting Times's Handgun Editor hunting with XP-100s, T/C Contenders and Encores, and Savage Strikers. (Long-barrel revolvers, too; same principle works there.)

I found the article here: http://www.shootingtimes.com/longgun_reviews/scout_102606/

It sort of makes sense to me so far as, as you go to a longer barrel you lose rigidity, and that that rigidity can be regained by going thicker on the barrel.

This sort of conflicts with the concept of heat control as the main reason for thickening the barrel. Or is it more of a complimentary sort of thing? That going thicker achieves both goals of rigidity and heat mitigation?
 
Both heat control and rigidity are benefits you get from a thicker barrel. A third benefit not mentioned is that a thicker barrel weighs more.

In some use cases one or more of these "benefits" might not matter, for example in big game rifles there is seldom a strong need to fire ten shots rapidly. Of course the "benefit" of weighing more (in target rifles heavier is better, up to a point) might be the opposite of what you want in a toteable rifle.
 
Isn't there a school of thought that shorter barrels may be more accurate due to having less barrel harmonics?
 
Just wondering if some of you guys can comment on this quote from an article I was reading:


I found the article here: http://www.shootingtimes.com/longgun_reviews/scout_102606/

It sort of makes sense to me so far as, as you go to a longer barrel you lose rigidity, and that that rigidity can be regained by going thicker on the barrel.

This sort of conflicts with the concept of heat control as the main reason for thickening the barrel. Or is it more of a complimentary sort of thing? That going thicker achieves both goals of rigidity and heat mitigation?


Because we build rifles with big heavy long barrels, F class shooters deal with this constantly. We use long barrels to get as much speed from the case as possible. The long barrel does make tuning more difficult but it can be overcome as shown by the spectacular results on paper.

The size of the barrel does not determine its accuracy. The quality of the bore and manf AND stress relieving does. Of course, things like chamber, action, bedding, optics, ammo, etc all play a role but assuming all else is keep constant, the barrels will shoot the same....

UNTIL, they get "hot" - thicker barrels have more mass so will take longer to reach a temp where accuracy MIGHT be affected. A quality match grade barrel properly stressed relieved can still shoot superbly even when it is scorching hot.

A thicker barrel is also more rigid making it less tempremental to tune.

The EASIEST barrels to tune then are the short (less barrel whip) and fat barrels (less barrel whip, longer to overheat). SR BR rifles are prime examples of this.

The worse would be a long skinny sporter with a magnum chamber. BUT there are some sporter magnums that can shoot very very well.

So the dimensions of the barrel doesn't tell you anything about its potential performance.

Jerry
 
Isn't there a school of thought that shorter barrels may be more accurate due to having less barrel harmonics?

From a mechanical point of view, shorter barrels (of the same thickness) vibrate less under identical stress.
But then again, the same cartridge and load does not impart the same stress in said barrels.

Hard to say...
 
Is there anything to this quote I found on another forum regarding new factory barrels?
You'll probably need to fire several hundred rounds of jacketed, or lap the bore, before you can tell what the barrel will really do. Still in pretty raw condition until it is broken in.

Is this true that jacketed rounds will have a lapping effect on a sort of rough new factory barrel?
 
A Look at the Rigidity of Benchrest Barrels by Daniel Lilja

Great articles with formulas :) and Basic code :( (where's my Commodore 64)

http://www.riflebarrels.com/articles/barrel_making/rigidity_benchrest_rifles.htm

Alex
 
I'd also like to ask a question about boyds stocks. Are they any good? I'd like the most accurate gun I can afford. Right now, I know the Stevens 200 plastic stock is screwing my accuracy possibilities.

First I'd like to go with a Boyds Prairie Hunter
Then I'd like to check out a Shilen

Is the Prairie hunter any good?
 
Is there anything to this quote I found on another forum regarding new factory barrels?


Is this true that jacketed rounds will have a lapping effect on a sort of rough new factory barrel?

That quote is pure bunk. Most of my Savage and stevens factory rifles have shot to their potential within 50rds of testing. In the chamberings that I was familiar with, inside 20rds.

That's a full load work up from a brand new rifle.

Any type of friction will 'lap' a barrel but if the defect is large enough, it will likely never be eliminated.

Most of the wear in a barrel happens in the throat and that is going to get worn pretty quick especially in larger chamberings.

Jerry
 
I'd also like to ask a question about boyds stocks. Are they any good? I'd like the most accurate gun I can afford. Right now, I know the Stevens 200 plastic stock is screwing my accuracy possibilities.

First I'd like to go with a Boyds Prairie Hunter
Then I'd like to check out a Shilen

Is the Prairie hunter any good?

If the factory stock is properly bedded AND the forend is opened up, it will be as accurate as any other stock.

My hunting rifles have all used the factory plastic stock and have no issue shooting to the potential of the factory barrel.

Proper bedding is the main reason for a lot of stock woes. There isn't enough weight on the forend to twist it during firing but to ensure best results, just rest the rifle within 3" from the recoil lug.

Boyds stocks are very well made and for the money, a superb buy.

But proper bedding and pillars is also important.

I just worked on a big name high end stock. The inletting was so bad, it surprised me. But once properly bedded, the rifle will be allowed to shoot to its potential.

Jerry
 
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