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Hello from Scotland~

Whilst sitting here pondering which .22 centre fire i should buy, .22 Hornet/.222/darn .223/ .22-250/.22 swift i started wondering about relative barrel length ?

What i mean is a .222 and a .444 may very well have the same length barrel , say 22" yet there is a VAST difference in actual bore size ie bullet diameter and relative barrel length ! If coverted into a ratio the difference must be huge ie would equate to a .444 with extremely long barrel indeed !

Just got me thinking about barrel length and the effect it has on our projectiles ? Such as velocity,accuracy relative to bore size, optimum length ?

I notice that alot of target rifle have barrels of 24"/25"/26"/27" is it simply weight that keeps sporting barrel lengths shorter ?

How important are our barrels dimentions?

Regards Englander
 

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Hello to the home of my distant ancestors,

There have been a number of tests run on barrel length, some of which concerned velocity and at least one which concerned accuracy. These go back into the '20s and '30s with Phil Sharp, Col. Whelan and others. The problem is the individual test may give an indication for a particular caliber, in a particular barrel. As you can determine, most barrels are very individual. Phil Sharp noted that to conduct a valid test, one would need at least 10 barrels of each caliber, and each chambering. A huge cost and undertaking. Then it might not apply to another chambering, with different capacity in a given caliber.

we can look at the experience over a lot of years and get some idea of the effect of length. For example, extra length will generally gain some velocity per inch. Or, to put another way, you will generally lose velocity as you cut inches off the barrel. How much is dependent upon caliber and case capacity. Then a different burning rate of powder may be more effective in the different length barrel.

Accuracy can also be effected by the length, as the harmonics will change with the change in length. A recent test indicated that a .22 cal. barrel showed the best accuracy at 16 1/2", after it was cut by an inch for each cut down to about 12". Obviously too late to save the 16" length. There was surprising little loss of velocity in that test.

The question you ask is one that has been asked for a lot of years, and to which there does not appear to be a definitive answer. One of the reasons that guns are so interesting.

Did this help or just confuse you?

dclark
 

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Hi, Gents:
Goto http://www.precisionshooting.com/ and click on the June issue cover for an article on barrel length. It seems that cutting an inch off at a time is a way too much. The Browning BOSS barrel tuner-muzzle brake often needs less than a full turn for results, according to articles I've read. (No personal experience.)

The full-bore target shooters like long barrels for two reasons. The longer barrel provides a longer sight radius when iron sights are required. Sometimes they use a short barrel for stiffness and add a light weight (bloop? boop?) tube on the end to extend the sight radius.

A .308 Winchester is required in some 1000 yard matches, and the bullets barely stay supersonic at that range. The low-drag bullets they use tend to tumble at the sound barrier and there goes the match. :( So long barrels and very healthy doses of powder are in order. Sort of like the .38 Super in IPSC, where the maximum load is also the minimum.

Bye
Jack
 

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General rules.

Whereas every rifle is individual, there are some basic rules.
The larger the case, the more sensitive it is to barrel length change.
Higher pressure rounds are more sensitive to barrel length change.
Smaller cases are more efficient; that is, they give more velocity per grain of powder than larger cases.
Shorter barrels shoot slower, but are handier.
 

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Depending on what you are looking for in the rifle you want to purchase/build/have built, you might be very well served by a shorter heavy barrel rather that a longer slender one. I can't speak to the velocity loss with Swift in the shorter barrel and suspect it would not be recommended because of the relativley large case capacity.

The late Bob Milek, and avid handgun hunter, did tests regarding this matter with the 22BR (I think, it's been some time) and it goes along with what DClark was citing as far as suprisingly little velocity loss with barrels down to single shot handgun length. The findings of the test where something to the effect that the shorter and stiffer barrel would outperform the same barrel when it was longer, accuracy wise, or at lease equal it.

I shoot Contenders and XP-100 pistols quite a bit and can tell you that you don't give up nearly as much performance as you might think when the barrel is only 15" in length. I can also tell you that either of the above handguns will typically outperform the average "off the rack" rifles as far as accuracy goes. I have a XP-100 that, from the factory, was a 7mm BR that would print 1/2-3/4moa with most loads I concocted for it, when I was doing my part. The gun has since been rechamber to .284 Winchester and still will easily print under 3/4-1 moa with no difficulty. I typically give up about 300 fps to the rifle length tubes in this chambering. This is with a Remington factory barrel. In the Contender in .223 I don't think I even lose 300 fps in the 14" barrel and it is very accurate. More recently I purchased a XP-100R in .35 Remington. I purchased it new and fired some factory ammunition for a baseline against which to compare my reloading efforts. The first 5 shots after 2 fouling shots in the new gun where right under 1 moa. My limited load development will produce 3/4 moa and occasionally less. The velocity with this pistol is actually geater than that of factory ammo in a rifle length barrel as result of being able to safely load higher pressures in the strong bolt action as compared to the lever action rifles this cartridge is typically chambered in. The barrel quality, rifling, of the .35 Remington is VISIBLY poor and will still shoot quite good groups, it's just a bear to clean. The type of accuracy I'm getting from the 2 XP's with light factory barrels supports the idea that the shorter barrels are stiffer and produce superior accuracy to a longer barrel of similar contour and quality.

I'm not scientifically inclined enough to answer eveything you are pondering, but as far as velocity and accuracy goes, the trade off in some velocity with the shorter tube my well gain you some accuracy in stiffness. If you used a 20" barrel on a .223 or .222 of a contour that allowed the same wieght as a more common 24" barrel, quality of tube and fitting being equal, I believe the 20" barrel holds more accuracy potential. I might be wrong on this, but my experience with the single shot handgun length tubes has been more than satisfactory in the accuracy department.
 
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