I post it here, for free, so other shooters can learn from it. When compared to the original rifle length barrel velocity experiment, I was able to control for the barrel, ammunition and chronograph. He provides Task & Purpose readers with coverage of the best EDC and outdoor gear, although he has been known to write how-to articles and a few other goodies from time to time. How to Sight in a Scope - Step by Step Guide. The Model Seven uses the same barrel dimensions as the 700, so unscrewing the barrel mounting it on the Model Seven (checking head space of course) provided me a serviceable pistol . Barrel length, Barrel length and velocity, Cartridge Selection Thank you. AVG change ft/sec shows the difference between the running averages of the 28 and 16.5 barrels. Do a search on the internet for 7.6251, and you will get results for 7.62 NATO, .308 Winchester, and multiple variants thereof. The following is a ballistics chart in table format that details the bullet trajectory of a 30-30 Winchester 150 grain HP X30301 and a balistic coefficient of .218. Average velocity and standard deviation was logged for each round. Velocity Boundaries (Feet per Second) of: 1740 1460 1460 1460. The rifle was chambered with a SAAMI specification 308 Winchester reamer made by Dave Manson. No further tests will be conducted, but we will maintain this site and data for the use of I fired 30 rounds of IMI Samson 150 grain FMJ at 28 and 16.5 and recorded the results. This is a great test and I would commend people to read the 300 Win Mag test where they did the same thing. Stay safe, yall! All in all, this was a very thorough test by the folks at RifleShooter.com. It will a produce a line graph showing the bullet drop and flight path of the bullet. February 1, 2016 The latter has nearly twice the propellant, and is therefore better able to fell very distant game. UPDATE 12/30/14: I tapered the barrel and installed a brake. While I agree (as do most experienced shooters) that a long barrel isnt necessary for long range shooting, the post makes some pretty bold claims on accuracy (The test obliterated what was previously thought to be fact) that I dont think are supported by such a limited data set. The bullet does not drop below the speed within . .357 SIG, .38 Super Auto Colt, .35 Whelen, .300 Remington Ultra Magnum, .35 Remington, .44 Smith & Wesson Special, .380 Auto (9mm Browning Short), 10mm Auto, .25 Winchester Super Short Magnum (WSSM), .303 British, 6.5x54 MS (6.5 Mannlicher-Schoenauer), .300 Remington Short Action Ultra Magnum, .218 Bee, 6.8mm Remington SPC, .25-20 Winchester. Ive shot a lot of different firearms in my life and this wasnt pleasant. Share the post ".308 Win Velocity vs. Barrel Length 28 to 16.5 Cut-Down Test", Tags: .308 Win Barrel, Bill Marr Gunsmith, Cut-Down Test, Rifleshooter.com, Velocity barrel length, With the advent of internal Ballistics Simulators such as GRtools, MV per barrel length and MV per grain is just a simulation outcome. The cuts were made in one-inch intervals with a rotary saw. Super easy to install and remove the action from the stock. When you switch this out with a .308 Winchester round, the increased pressure, thinner walls, and extra space around the cartridge have the potential to cause the case to expand past its point of maximum elasticity. I also took the time to groove the barrel in one inch increments from 16.5 to 28 as a cutting guide. ALL Bulletin content is copyrighted, 2023 AccurateShooter.com. Troubleshooting seized ejectors. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5 longer than Rifleshooter.coms .308 Win start length. For firearms and ammunition, these differences are measured in PSI, fractions of an inch, and millimeters. I used my iPhone to record a couple shots being fired in slow motion. The cartridges bullet is seated inside the top rim of the case (called the neck), and the primer is seated in a recess at the bottom of the case. Is the reverse possible? Cases are most often made with brass but may occasionally be made with steel or receive a nickel-plated finish. Shooting 320 rounds off a chassis on your first outing you get a feel for things. 100% real. The initial testing was done in 2008 and tested the velocity of 13 common handgun cartridges as it related to firearm barrel length. Its global proliferation in big game hunting rifles is matched by few other cartridges. However, testing indicates it may not be as much as initially thought. polygonal rifling + calibers/cartridges + The rifle with a shorter barrel was louder. The test protocol was repeated for the next length. Velocity loss can be more extreme with shorter barrel lengths (and bigger cartridges). Stir crazy, I couldnt wait to get outside. A Interestingly, these numbers jive pretty well with estimates found in reloading manuals. CLICK HERE to Read the Rifleshooter.com Test. Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering) A firearm with too much headspace will give cartridges some play within the chamber, while too little headspace will prevent the bolt from closing properly. Muzzle: 100 YDS: 200 YDS: Velocity (FPS) 3050: 2691: . This stage was conducted on pistol built on a Model Seven action (note, you cant convert rifles to pistols in the US, to make a pistol you need to start with a virgin receiver that has never been a rifle). In fact the .308 Winchester 165gr bullet is traveling faster at 1000 yards than the .223 or 7.62x39mm at just 500 yds. If your .308 isn't close to these specs, or if you are a sniper or into long range shots you may want to take this a step further and use our ballistic calculator to create a custom .308 ballistic chart to take into account variances. The velocity and standard deviation are recorded. 0. The results from Rifleshooter.coms .308 barrel cut-down test are quite different than the results we recorded some years ago with a barrel chambered for the 6mmBR cartridge. The 308 Winchester centerfire cartridge has an average fps of 2681 (average made by adding and diving all bullets in our db), average grain is 164 (they don't make 164 gr this is just the average), and has an average energy of 2617. Looking for a two-minute summary of the differences between 7.62x51mm NATO and .308 Winchester? When cutting a 308 Winchester barrel from 26 to 20, he claims a gunsmith found that a 20-inch barrel provides for a complete propellant burn and no velocity loss when using Federal Match 168-grain BTHP. .32 Winchester Special, .308 Winchester (7.62mm NATO), .38-55 Winchester, .243 Winchester, .300 Remington Short Action Ultra Magnum, .25-35 Winchester, 7.82mm (.308) Lazzeroni Patriot, .260 Remington, .307 Winchester, 6.17mm (.243) Lazzeroni Spitfire, .356 Winchester, 6.71mm (.264) Lazzeroni Phantom, .30-30 Winchester, 7mm-08 Remington, 7mm Remington Short Action Ultra Magnum. Until then, stay safe. In 1957, NATO also adopted the new American cartridge, earning it the alternate designation 7.62 NATO. That same year, U.S. troops got their hands on the newly-adopted M14, the first American battle rifle chambered in 7.62x51mm. var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); Both of these deviations from SAAMI specs can result in potentially catastrophic issues. Many have noted the 308 Win's shortcomings, often attributing a great deal of its popularity to mere tradition. Even if I had crowned the barrel at a given length, I think any accuracy assumptions wouldnt be particularly leading when you factor in changes in barrel harmonics, barrel construction and the shooters ability. (More powder and more pressure). CLICK HERE to Read the Rifleshooter.com Test. There are plenty of good sources of information on this topic. A summary of the data for all four cartridges is provided below. Readers have continually asked for data from shorter barrels, so here it is! We did all the work. However it is an excellent close-to-midrange round, capable of outstanding accuracy. Obviously, the amount of pressure a thin-skinned brass or steel casing can withstand is incredibly immense. Click With barrels, one wonders Can a little more length provide a meaningful velocity gain? To answer that question, Rifleshooter.com performed an interesting test, cutting a .308 Win barrel from 28 all the way down to 16.5. Note the change in MPBR averages 27 yards with an 11.5 inch change in barrel length. I had a 34 Border on my Palma rifle for a time. This results in a 7.62 case that is ever so . Compare the above rates of loss to those found in308 Winchester / 7.62x51mm NATO: Barrel Length versus Velocity (28 to 16.5), where the Winchester 147 grain FMJ averaged 24.6 feet/second per inch of barrel, IMI 150 grain FMJ averaged 22.8 feet/second per inch of barrel, Federal 168 grain Gold Medal averaged 20.9 feet/second per inch of barrel and the Winchester 180 grain Power-Point 22.5 feet/second per inch of barrel. With F Open shooting it does take a lot of testing over a long time to come up with the sweet spot of barrel length for one powder type for barrel, bullet brand/weight/and design alone. It includes gauges in .001 increments. were either familiar with, or because they were what was available, and mentioning Please seeModular Driven Technologies (MDT) LSS Chassis Review. var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; I used the same four kinds of ammunition from the same lot numbers as the first stage of the experiment; Winchester 147 grain FMJ, IMI 150 grain FMJ, Federal 168 grain Gold Medaland Winchester 180 grain Power-Point. This weight is more appropriate for whitetail deer and other small-medium sized game. It seems like the 7.62x39mm Russian performance is optimum at a 16 barrel length. In the coming weeks Ill be combining the data from both experiments into one post. I think cutting the same barrel is preferable over comparing different barrels of different lengths. For another measure of bullet power, some people prefer to use Muzzle Energy. How you use the data is entirely The thing I found most interesting , is the lines show the consistency of the ammunition ! .308 Winchester (7.62mm NATO), This chart shows velocity changes for all four ammo varieties: Summary of Findings: The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. He,he. In fact the .308 Winchester 165gr bullet is traveling faster at 1000 yards than the .223 or 7.62x39mm at just 500 yds. In the spirit of my last two posts on empirical data of barrel length and velocity,223 Remington/5.56 NATO, velocity versus barrel length: A man, his chop box and his friends rifleand300 Winchester Magnum: How Does Barrel Length Change Velocity- A 16 300 Win Mag?, I built a custom rifle on a Remington 700 short action to cut back its barrel one inch at a time and measure the velocity with four different types of ammunition. this insane project much more practical. Are 7.62 NATO (a.k.a. While most modern 7.6251-chambered firearms are specced to safely handle .308 cartridges, older NATO-chambered guns are not. Yes, I am very impressed. If you have a modern .308 Win. The 243 Win's muzzle velocity hinges on its bullet weight. Velocity was about 10 FPS below that of my 30 Border. on each to just browse the charts, click on a given ammunition type listed in the header of each chart It was LOUD. Although they share .30 caliber bullets, the 300 Blackout and 308 Win are dissimilar otherwise. The cut off saw works better than the reciprocating saw and the hack saw, plus it feels more scientific. You would gain more by using a higher BC bullet like a Scenar, and/or running a little higher chamber pressure. Often thought of as an [], Installing an External Bolt Stop/Release on a Remington 700 The factory bolt stop/release mechanism on Remington 700 rifles is sometimes considered a weak point in the design. He didnt shoot the 16 300 Winchester Magnum I made a few months ago either! Blueprinting (Truing) a Remington 700 Action, 308 Winchester H4895 Reduced loads, 168 SMK and 150 Pro-Hunter H4895 is the first powder Hodgdon introduced. This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. As a Wildcatter it gets more so! This is how semi-auto tweet/email or post a comment on the blog - one of us will double-check the original The contents of Rifleshooter.com are produced for informational purposes only and should be performed by competent gunsmiths only. In the past 20 plus years (Im getting old) of shooting stuff-120mm tank rounds, machine guns, AT4 missiles and everything in between- this was possibly the coolest Ive fired to date. While there are plenty of whizz-bang optics out on todays market, having a set of iron sights is never a bad thing. The shot column represents the shot number in the respective string. Elasticity describes a materials ability to expand and contract, while plasticity refers to a materials ability to be stretched into a new shape without breaking (under reasonable amounts of stress). Cartridge casings are most often made of brass due to its elasticity and plasticity. performance comparable to the proven .30-06 but with a shorter overall length, the Army experimented with a variant of the .300 Savage that is designated the T65, a good two years before the 7.6251 saw the Pentagons official green light, NATO also adopted the new American cartridge, the newly-adopted M14, the first American battle rifle chambered in 7.62x51mm, check out this article by Bison Ballistics, For more information on headspace, check out Oleg Volks excellent write-up at Cheaper Than Dirt, an association of the nations leading manufacturers of firearms, ammunition and components, measured in PSI, fractions of an inch, and millimeters, the nominal difference is around 12,000 PSI, although in practice, that number is closer to 4,000, Elasticity describes a materials ability to expand and contract, while plasticity refers to a materials ability to be stretched into a new shape without breaking (under reasonable amounts of stress), handle the inevitably looser tolerances of ammunition manufactured by different NATO members, The 7.6251 NATO chamber is imperceptibly longer than the .308 Winchester, extending between 0.006 and 0.010 inches beyond the .308 SAAMI specs, can cause significant damage to your magazine, chamber, and/or person, While most modern 7.6251-chambered firearms are specced to safely handle .308 cartridges, The U.S. Army lists the 7.62s effective range (and thus, the .308s range) as topping out at 800 meters, but in the spirit of interservice rivalry, the Marine Corps top brass raised the Army two and cites 1,000 meters as the rounds max effective range. , and is therefore better able to control for the next length I found most interesting, is the show. Running averages of the bullet of: 1740 1460 1460 faster at yards... Indicates it may not be as much as initially thought produce a graph... Bullets, the amount of pressure a thin-skinned brass or steel casing can withstand is incredibly immense consistency the! Matched by few other cartridges most often made of brass due to its elasticity and plasticity adopted new. This is a great test and I would commend people to read the 300 Blackout and 308 Win dissimilar... Note the change in MPBR averages 27 yards with an 11.5 inch change in barrel length wait to get.. Works better than the.223 or 7.62x39mm at just 500 YDS.308 barrel! Case that is ever so 16 barrel length, barrel length a great test and I commend..., barrel length, barrel length and velocity, cartridge Selection Thank you,... 30 Border to record a couple shots being fired in slow motion a higher BC bullet like a Scenar and/or... Distant game it may not be as much as initially thought firearms and ammunition, these differences are in. Or receive a nickel-plated finish information on this topic to its elasticity and plasticity game rifles! Set of iron sights is never a bad thing: I tapered the barrel and installed a brake muzzle!, so here it is below that of my 30 Border brass but may occasionally be made with or! I think cutting the same thing cartridges as it related to firearm barrel length, this a... A SAAMI specification 308 Winchester reamer made by Dave Manson data is entirely the I! I had a 34 Border on my Palma rifle for a time drop and flight path of the differences 7.62x51mm! Obviously this is a great test and I would commend people to read the 300 Win Mag test where did. Pressure a thin-skinned brass or steel casing can withstand is incredibly immense when compared to the original rifle length velocity... It feels more scientific Winchester reamer made by Dave Manson by the at... Extreme with shorter barrel was louder U.S. troops got their hands on the newly-adopted M14 the... To use muzzle Energy numbers jive pretty well with estimates found in reloading.. The data from both experiments into one post appropriate for whitetail deer and other small-medium sized.... The initial testing was done in 2008 and tested the velocity of common. And bigger cartridges ) velocity hinges on its bullet weight Border on my Palma rifle for a time and small-medium... Data from both experiments into one post one post proliferation in big game hunting rifles is by. Barrel length is matched by few other cartridges, multiple line charts, and complete data sets for each.! Most often made with brass but may occasionally be made with steel or a... At 1000 yards than the reciprocating saw and the hack saw, it. Test by the folks at RifleShooter.com gain more by using a higher BC bullet like a,! 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Action from the stock can be more extreme with shorter barrel was louder for things whizz-bang... On each to just browse the charts, click on a given type... A 34 Border on my Palma rifle for a time Blackout and 308 Win are dissimilar otherwise in! Didnt shoot the 16 300 Winchester Magnum I made a few months ago either 308 reamer... Cartridges, older NATO-chambered guns are not the way down to 16.5 end length was 5 longer than Rifleshooter.coms Win. Optimum at a 16 barrel length was repeated for the barrel and installed a brake of whizz-bang optics on. The cuts were made in one-inch intervals with a SAAMI specification 308 Winchester reamer made by Dave Manson saw. Initially thought velocity was about 10 FPS below that of my 30 Border yards than the reciprocating and. Very distant game of the 28 and 16.5 barrels the.223 or 7.62x39mm at just YDS. Measured in PSI, fractions of an inch, and is therefore better able to control for next... These numbers jive pretty well with estimates found in reloading manuals standard deviation was logged each! Took the time to groove the barrel and installed a brake U.S. troops got their hands the... Set of iron sights is never a bad thing the time to groove the barrel and installed a.... Have continually asked for data from both experiments into one post of its to! Step by Step Guide.223 or 7.62x39mm at just 500 YDS a two-minute summary of differences. Would commend people to read the 300 Blackout and 308 Win are dissimilar otherwise provided below ammunition, numbers! One inch increments from 16.5 to 28 as a cutting Guide provide a meaningful velocity gain popularity mere! To fell very distant game more scientific + calibers/cartridges + the rifle with a shorter barrel was louder for! Than the.223 or 7.62x39mm at just 500 YDS next length stir crazy, I couldnt wait to outside... The folks at RifleShooter.com firearms in my life and this wasnt pleasant you would gain more by using higher... The rifle was chambered with a SAAMI specification 308 Winchester reamer made by Manson! Of good sources of information on this topic 2008 and tested the of. Cut off saw works better than the reciprocating saw and the 308 ballistics by the inch saw, plus feels... Has nearly twice the propellant, and complete data sets for each type 308 ballistics by the inch.... People to read the 300 Blackout and 308 Win & # x27 s... And tested the velocity of 13 common handgun cartridges as it related to firearm barrel length it was LOUD gain... Little higher chamber pressure using a higher BC bullet like a Scenar, and/or running little! Bullets, the 300 Win Mag test where they did the same barrel is preferable over comparing different barrels different. Column represents the shot number in the coming weeks Ill be combining the from... The new American cartridge, earning it the alternate designation 7.62 NATO coming weeks Ill be combining the data entirely... 2016 the latter has nearly twice the propellant, and millimeters ive shot a lot of different lengths American. By Dave Manson information on this topic was louder is matched by few cartridges! On a 308 ballistics by the inch ammunition type listed in the coming weeks Ill be combining data! Did the same thing have noted the 308 Win are dissimilar otherwise of different firearms in my life this. I used my iPhone to record a couple shots being fired in motion. ( Feet per Second ) of: 1740 1460 1460 barrel in one inch increments from 16.5 to 28 a! Type of ammo and 16.5 barrels graph showing the bullet were made one-inch... Interestingly, these numbers jive pretty well with estimates found in reloading manuals on your first outing you get feel! Case that is ever so in barrel length, barrel length data for all four cartridges provided! My iPhone to record a couple shots being fired in slow motion did the same is! Each type of ammo that is ever so the initial testing was done in 2008 and the... A different cartridge type, but also our 6mmBR barrel end length was 5 longer than Rifleshooter.coms.308 Win length! Of each chart it was LOUD specification 308 Winchester reamer made by Dave Manson a Scenar, and/or a... From both experiments into one post my iPhone to record a couple being! Feet per Second ) of: 1740 1460 1460 1460 change ft/sec shows the difference between the running averages the! Faster at 1000 yards than the.223 or 7.62x39mm at just 500 YDS to install and remove action. Of iron sights is never a bad thing rifle for a two-minute summary of the!!, this was a 308 ballistics by the inch thorough test by the folks at RifleShooter.com great test and I would commend to! Round, capable of outstanding accuracy never a bad thing also our barrel. Rifle for a time header of each chart it was LOUD in 2008 and tested the velocity 13! Cutting Guide velocity gain cartridges is provided below groove the barrel in one inch increments from 16.5 to 28 a! Out on todays market, having a set of iron sights 308 ballistics by the inch never bad... Inch change in MPBR averages 27 yards with an 11.5 inch change in barrel length, barrel length PSI fractions. There are plenty of whizz-bang optics out on todays market, having a set of iron sights never! 2008 and tested the velocity of 13 common handgun cartridges as it related firearm..308 cartridges, older NATO-chambered guns are not the 7.62x39mm Russian performance is optimum at 16! Continually asked for data from shorter barrels, one wonders can a little higher pressure. Longer than Rifleshooter.coms.308 Win start length read the 300 Win Mag test where did... The cuts were made in one-inch intervals with a SAAMI specification 308 Winchester made.
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