Re: Good article on barrel length
From: Guns magazine, by Clint Smith
just found this last night.
There is often a general belief that longer barrels are more accurate than barrels of a shorter configuration. Part of this thought may extend from the period when most rifles were equipped with iron sights.
In that era the longer sight radius provided by a lengthy tube equated to better, more consistent accuracy at long range. Changes in the dynamics of powder, as in the transition from black powder to smokeless, had a cause and effect factor on accuracy and on the barrel length required to gain the most effective results.
Progressing forward, quantum leaps in optics design and application helped to provide better target acquisition--another positive contribution to accuracy not directly related to barrel length. Vastly improved projectile design and construction also. I believe, helped to nullify the advantage of the long barrel.
Assumptions Vs. Truth
It's important to remember that much of what we see and read is often mere marketing or the "new kid on the block" mode. The new trendy short magnums and spiffy projectiles do not in fact compensate for poor marksmanship any more than long barrels necessarily equate to better accuracy.
In some hunting camps it's always the newest long-barreled mega-magnum with a glass atop akin to an astronomer's telescope that garners the most attention. So do we really need the long barrel for the reasonable ranges where we may hunt or shoot? With the help of the Thunder Ranch range boss Pete Nantirux we set out to learn the truth.
The basic premise was that we would commence with a 24-inch barrel, test for accuracy and velocity, and then shorten it two inches at a whack before repeating our testing.
The Rifle
There are many of choices and to each his own. For purposes of this research the test platform was a right-handed Remington M700 long action. It can safely he described as an industry standard.
For a stock we selected a Robar SR60-2 with the adjustable check piece. Other than the adjustable cheek piece the stock is a pretty plain affair, although it is set up with pillar bedding appropriate to this type of rifle.
The Barrel
Robbie Barrkman of Robar, Inc. barreled the Remington action with a .095-inch diameter barrel made by Dan Lilja. Without a doubt Lilja barrels are some of the finest made today. Even though by some people's standards we did a hatchet job on the barrel during this testing, there can be no question that the barrel was a good one and we truly got our money's worth out of it. And as it turns out it wasn't such a hatchet job either.
One thing I am absolutely sure of is that Rubble gave us a carefully executed, match-grade muzzle crown with each new cut. From what little I know of it, the even exit of the projectile from the muzzle is critical to rifle accuracy regardless of the barrel length. A good crown--perfectly square to the bore--gives a good exit of the projectile and the exiting gases as well. The accuracy we achieved across the board is a testament to the care with which Barrkman shortened and crowned our barrel as much as any of the other factors involved.
The Optics
With the help of Garth Kendig of Leopold & Stevens Corporation the rifle testing was done with a fine Leupold scope. The new model 54680 Long Range M1 is a 6.5-20 power scope with 1/4 MOA adjustments, matte finish and mil-dot reticle. Trust me, we stretched out every bit of this glass over the test. Mounted on a 20 MOA plus base from Brownells, we never came close to running out of dope for this rifle and scope combination. Being forthright I admit I've always been a fan of Leupold optics, and this new scope confirms again to me why I am.
Set up with central control design it places all the oversize knobs and side focus adjustments within easy reach and operation. The scope is built on a 30mm tube with eye relief at a nominal 4 inches and a weight of 22 ounces. Although I didn't freeze it in a block of ice or beat the Shot out of it with a hammer, we did pound the bejeepers out if it with gunfire.
Leaving the scope mounted in the rings it held every adjustment we put in it and returned to zero within an inch for each of the four times we removed it from the rifle before shipment for barrel shortening. The top end 20 power is a bit much for general use, but then this is not a general use scope. For purposes of this test of rifle and accuracy the scope served this purpose well and effectively.
Ammunition
Several types of ammunition were initially tested for accuracy in the 24-inch barrel. Without doubt or reservation the Black Hills ammunition used in the testing was the most accurate across the board. All of the ammunition used was from the same lot number and was Black Hills .300 Winchester Magnum loaded with 190-grain match JHP. As the test groups document only one group fired went over minute of angle, and this is strongly inclined to be operator error rather than ammunition related.
The Test
All the testing was done on the same range located at an elevation of 2,280 feet above sea level. All chronographing was done at a measured eight feet from the muzzle. Some testing was slightly delayed to get the correct day and time of day to keep the temperature and humidity spread to a minimum over the whole testing process. All firing was done from supported rests while using a rear bag for additional stability. Five shot groups were fired.
Examine the chart and you'll see the total nominal velocity loss was 350 fps as the barrel was shortened from 24 to 16 inches. For comparison, the nominal muzzle velocity of the .30-'06 with a 180 grain loading is 2,700 fps; and for the .308 Winchester with the same bullet weight, 2,400 fps.
The Final Configuration
In its final form the rifle weighs in at nine pounds complete with scope, with an overall length of 37 inches. We elected to leave the rifle and scope combination together rather the down sizing to a smaller scope although the scope is down on the low setting of 6.5x for normal use. The Robar adjustable stock is lowered to the lowest setting and locked, as a higher comb is not required with this stock, barrel and scope setup.
On the final day of the test, July 6, 2003, while sitting on the 300 yard line, a scope adjustment was made to engage a 24-inch square plate which is available to us at 1,100 yards. After the first six shots were fired and adjusted the rifle and scope combination was on target for five consecutive hits--Pete then shot five founds and got another five consecutive hits on the plate. Not too shabby performance for what many would presume to be an "inaccurate" short-barrelled rifle. We stopped for the day and cleaned the rifle.
Final Thoughts
In low light environments there is a pronounced muzzle signature with the .300 Winchester dressed in the short barrel. A rifle of this configuration, if there was a need for one for police and military application, may require a signature suppression package.
On the upside, the rifle is much handier in this form than when we started with the full length 24-inch barrel. The short 16-inch barrel is accurate and this point is not even open for dispute. By cutting the barrel we have basically evolved to a rifle with .30-'06 velocity but yet delivering a wind bucking, 190-grain projectile from a very handy package.
As we started this testing I told Pete that when we were done he could have the rifle, his comment was, "Oh no sir. I couldn't possibly take the rifle." As we finished the last of the testing his prior comment was replaced with, "Boy I sure like my new rifle!"
Yeah, I know he means--I like Pete's new rifle too.
Date Temp. Barrel 100 Yards 200 Yards
4-10-'03 24" 73F 5/8" 1 1/4"
5-6-'03 22" 78F 1/2" 1 1/4"
6-16-'03 20" 78F 1" 1 1/8"
6-28-'03 18" 79F 3/4" 1 1/4"
7-6-'03 16" 77F 1/2" 2 1/8"
Date 300 Yards Velocity Velocity Lost
4-10-'03 2 3/8" 3,014 fps n/a
5-6-'03 1 1/16" 2,937 fps 77 fps
6-16-'03 2 3/16" 2,827 fps 110 fps
6-28-'03 2 3/16" 2,709 fps 118 fps
7-6-'03 2 1/4" 2,667 fps 42 fps
