A question of length.

[Die Judicii]

Not being well versed in the following, I'm wondering what some of you blokes have to say.

The old ?cure for a rifle that's started to drop off in accuracy of cutting off half an inch of barrel and re crowning which I've never done was supposed to be a fix.
For arguements sake lets presume the caliber to be 22/250.

How many half inch bits can be cut off before the "shortened" barrel then becomes inherently innaccurate ?

Or,,, the same thing in reverse,, (presuming that a barrel can hypothetically be lengthened)
Would the differing barrel lengths therefore change the accuracy/consistency of the firearm ?

ie: A 22/250 rifle that is available from new, with the same rate of twist, but different barrel lengths.

Would that make the two separate rifles shoot entirely different to each other ?

[Oldbloke]

Well, we are assuming the crown is the problem?

Down as far as 20" is popular in NZ. If permitted in yr state.
Assume about 30fps loss per inch

Anyone with a small lathe can do it.

[on_one_wheel]

I would probably set the projectile closer to the lands before lopping off the crown (assuming the crown looks good)
It's not uncommon to adjust depth as the rifle wears.

[bladeracer]

Not being well versed in the following, I'm wondering what some of you blokes have to say.

The old ?cure for a rifle that's started to drop off in accuracy of cutting off half an inch of barrel and re crowning which I've never done was supposed to be a fix.
For arguments sake lets presume the caliber to be 22/250.

How many half inch bits can be cut off before the "shortened" barrel then becomes inherently innaccurate ?

Or,,, the same thing in reverse,, (presuming that a barrel can hypothetically be lengthened)
Would the differing barrel lengths therefore change the accuracy/consistency of the firearm ?

ie: A 22/250 rifle that is available from new, with the same rate of twist, but different barrel lengths.

Would that make the two separate rifles shoot entirely different to each other ?

Maybe a cast of the last few inches of the muzzle so you can measure the rifling and see if that is the problem. Casting alloy isn't expensive and is infinitely reusable. I would think the throat would be more likely to be the problem, which requires removing the barrel, cutting it, and rechambering it.

I don't think anybody has been able to show that a longer barrel is inherently more accurate than a shorter one, at least not on a scoped rifle. Whether the specific rifle/barrel has harmonic nodes in the barrel length that just will not shoot well though can't really be known until you cut it and see.

[Die Judicii]

I never said the crown was a problem, or the rifleing,,,, it was a hypothetical question
Perhaps just concentrate on the "last question" in my original post.

Would two new rifles (both the same brand, twist rate and same caliber, and using the same ammo,, shoot to any marked degree different to each
other when one has a long barrel and the other a short barrel ?

[bladeracer]

I never said the crown was a problem, or the rifling,,,, it was a hypothetical question
Perhaps just concentrate on the "last question" in my original post.

Would two new rifles (both the same brand, twist rate and same caliber, and using the same ammo,, shoot to any marked degree different to each
other when one has a long barrel and the other a short barrel ?

You opened your question specifically talking about the results of shortening a barrel to fix a problem...

I can see no reason why they would. It's certainly possible one might shoot better than the other, no two rifles are identical, but there is no "rule" I know of that says which is likely to shoot better based on barrel length. The factory will have made a somewhat arbitrary decision about barrel length, and then tested the rifle to get it to shoot well with that length. They might have gotten it wrong and it might well shoot better with a shorter barrel, or they might've gotten it right and it'll shoot worse. But this is not because of the barrel length alone, it's because of the way the complete rifle reacts when fired, often as result of the ergonomic connection to the shooter.

[Wapiti]

Mate I found that a shorter barrel actually is consistently more accurate, all things being equal.

That is my user experience.

A shorter barrel compared to a longer one of the same diameter, will be stiffer of course.

As we know, barrels oscillate and whip during the firing process, and a stiffer barrel will potentially flip at the muzzle less, or potentially the harmonics will be more consistent. Result is the projectiles exit at less of a violent point when they do so, meaning potentially smaller groups.
A longer barrel will need to be of a much larger diameter, hence way heavier in weight, to get the same result.
I was working with John Giles, a revered accuracy rifle gunsmith on a rifle for long range here at the farm, and wanted a giant Lilja 30" barrel for another 300 RUM. He told me of the problem that this actually put bending stresses on the action and was detrimental to consistently. Which is the same thing as above, but opposite.
I have cut and recrowned barrels that were really finicky b@srards, and it settled them down a lot. It was either my new crown cut or changing the harmonics by being shorter.

In factory rifles, I can give an example...
I had a 2 Remington 700 Police 308 rifles, one my wife used, one I did.
Both had excellent HS Precision alloy bedded stocks, Mark 4 mounts and Leupold Mk4 scopes. But one was the factory 20" barrel, and one was the 26".
Both were incredibly accurate, and would shoot tiny cluster 5-shot groups at 100m with good loads, but the 20" shot nearly everything incredibly well without any tuning, where the 26" was very fussy. Bear in mind though that all rifles are different. Still got one of them, on its second barrel.
And ferals shot with both, using the same projectiles, had exactly the same terminal effect and instant death because the "must get more velocity " perversion people have is also BS if the cartridge is adequate in the first place.

But for all that, I have found that a shorter barrel of the same diameter as a longer one is of course stiffer, and is more consistently accurate. Actually thats just physics. The "shorted a barrel, the less accurate" myth is just bullsh*t.

Velocity is a different matter, shorter means slower generally, but when does this ever matter? Playing with different powders can negate this a bit but not everything. Velocity doesn't matter a bit if the rifle isn't consistently accurate.

[bladeracer]

I don't have any data to support it but my personal view is that I can shoot more accurately with a shorter barrel, regardless of whether the rifle is more accurate with the shorter barrel. I used to believe this was party related to how long the bullet is moving within the barrel, any movement of the shooter/rifle during those milliseconds will effect accuracy. But I've been shooting the front-heavy Rossi 24" octagonal .357 offhand a lot recently and that works very well for me also. So, overall I prefer shorter barrels, but in a lot of the high-velocity rifle chamberings the "muzzle blast" (with full power loads) that comes with them can make the experience less enjoyable than it should be, so you might want a longer barrel for personal comfort more than anything to do with the rifle. For precision shooting with iron sights though a longer barrel is probably the way to go just for the longer sight radius, even if you have to counterbore the muzzle to shorten the length of the actual barrel.

Agreed about velocity. The highest achievable velocity is great when you are reaching out to the maximum possible range of the cartridge or bullet, but how often are we doing that? Some bullet designs only work within a narrow terminal velocity window, and terminal velocity is tied to range. It's better to match your terminal velocity window to suit the ranges you expect to be shooting, rather than simply push for maximum velocity. I use reduced loads for close-range shooting and keep full-power loads for the rare occasions I might want to reach out.

Mate I found that a shorter barrel actually is consistently more accurate, all things being equal.

That is my user experience.

A shorter barrel compared to a longer one of the same diameter, will be stiffer of course.

As we know, barrels oscillate and whip during the firing process, and a stiffer barrel will potentially flip at the muzzle less, or potentially the harmonics will be more consistent. Result is the projectiles exit at less of a violent point when they do so, meaning potentially smaller groups.
A longer barrel will need to be of a much larger diameter, hence way heavier in weight, to get the same result.
I was working with John Giles, a revered accuracy rifle gunsmith on a rifle for long range here at the farm, and wanted a giant Lilja 30" barrel for another 300 RUM. He told me of the problem that this actually put bending stresses on the action and was detrimental to consistently. Which is the same thing as above, but opposite.
I have cut and recrowned barrels that were really finicky b@srards, and it settled them down a lot. It was either my new crown cut or changing the harmonics by being shorter.

In factory rifles, I can give an example...
I had a 2 Remington 700 Police 308 rifles, one my wife used, one I did.
Both had excellent HS Precision alloy bedded stocks, Mark 4 mounts and Leupold Mk4 scopes. But one was the factory 20" barrel, and one was the 26".
Both were incredibly accurate, and would shoot tiny cluster 5-shot groups at 100m with good loads, but the 20" shot nearly everything incredibly well without any tuning, where the 26" was very fussy. Bear in mind though that all rifles are different. Still got one of them, on its second barrel.
And ferals shot with both, using the same projectiles, had exactly the same terminal effect and instant death because the "must get more velocity " perversion people have is also BS if the cartridge is adequate in the first place.

But for all that, I have found that a shorter barrel of the same diameter as a longer one is of course stiffer, and is more consistently accurate. Actually thats just physics. The "shorted a barrel, the less accurate" myth is just bullsh*t.

Velocity is a different matter, shorter means slower generally, but when does this ever matter? Playing with different powders can negate this a bit but not everything. Velocity doesn't matter a bit if the rifle isn't consistently accurate.

[Billo]

My most accurate rifles have barrels between 18-22 inches

[Die Judicii]

Thank you Wapiti and Blade,
Between the two of you, your comments/suggestions have concurred with what I've been angling.

[Wapiti]

Great discussion. I've always beived that if you really want to get a certain diameter/weight of bullet going super fast for any reason, it's better to just get a bigger cartridge case.

But, I've got a real liking now for shorter barrels, 16-20" in the 223, and 20" tops in the 308.
There's a drop in velocity, but within the ranges I can humanely and practically-wise shoot, the damage to the game is not even conceivably different one bit.
And for long range stuff, it's merely clicks to your scopes elevation, which you have to do anyway.

But then, if I chose a 20" barrel for a 300RUM, that would be pretty self-defeating. A spectacle for sure, but a waste of time.