The vast majority of rifles, carbines, and pistols chambered in .308 Winchester can safely sling 7.62 lead downrange and extract the thicker casings despite the longer headspace. Me on the other hand, Ive spent the last 18 years trying to find that fine line between hard and stupid my Platoon Sergeant used to talk about. It fires a .312-inch-diameter bullet as opposed to a .308-inch-diameter bullet and operates at 45,000 psi as opposed to 40,000. I selected Federal 190 grain Gold Medal ammunition for this test. Take this into consideration when comparing calibers using our Your choice. home + Hydra-Shok JHP: Speer 200 gr. The small sample size is always an issue. No, I did not. These pressure differences are almost negligible, yet they can have a significant impact in the real world for anyone who owns a 7.62-chambered firearm or who likes to reload their own ammo. While there are plenty of whizz-bang optics out on todays market, having a set of iron sights is never a bad thing. And thanks to our spouses, who were not just tolerant but enthusiastically supportive My lathe is a two hour round trip to the range. Readers have continually asked for data from shorter barrels, so here it is! SDs and ES were superior from the longer barrel, as was the sight picture. site designed and maintained by Coeurbois Graphic Design. 30-30 Ballistics Chart & Coefficient. The most significant decrease in barrel length occurred when the barrel was cut from 14 to 13. When you pull the trigger on your M14, it starts a chain reaction. It's fine to 600-800 yards and is fine at that range out of an 18" barrel. .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. })(); To comment on a post, click Post Title or "Comment" Link. Please seeModular Driven Technologies (MDT) LSS Chassis Review. We stopped at 500 yards, but I had some legit 2.5 500 yard 5 shot groups. 300 Winchester Magnum: How Does Barrel Length Change Velocity- A 16 300 Win Mag? was measured from the end of the barrel back to the breech face. Based on my limited experience with the 330 BLK and 7.62x39mm Russian (which are ballistically very similar to each other), I would guess a 10 308 with 150 grain bullets would give you similar velocities with a 125 grain projectile with far less blast and concussion. Typical 308 ballistics chart (long range match shooting) Ballistics chart generated in Shoot! photo link: http://rifleshooter.com/wp-content/uploads/2015/01/custom-16.5-rem-700-308.jpg. ALL Bulletin content is copyrighted, 2023 AccurateShooter.com. I may wear a lab coat to kick things up another notch next time. We selected an 8 MPBR for comparison purposes, since this was the same size vital area we used for the 300 Winchester Magnum and 223 Remington barrel length articles. Velocity was about 10 FPS below that of my 30 Border. You may not reproduce original text or photos without advanced permission in writing. A Here are some pics: I get this every so often. Although they share .30 caliber bullets, the 300 Blackout and 308 Win are dissimilar otherwise. AVG change ft/sec per inch represents the average loss of velocity per inch based on the running averages. 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; In the good old days of Precision Shooting magazine (how we miss you! 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. The barrel was cut off using a cold saw. I shook vigorously from head to toe. Here is a list of all 23 different data sets we have tested. 0. All 7.6251 rounds are cool for use in the proper NATO weapon, but 7.62x39 is the original caliber of the infamous AK-47. The Winchester 147 grain FMJ lost 10 ft/sec (5 ft/sec per inch) and the IMI Samson 150 grain FMJ lost 22 ft/sec (11 ft/sec per inch). 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. I like it a lot. Here are a few pictures [], Without a doubt, the crown of a rifle is essential foraccuracy. I will actually contour what is left and use it on a custom build. Do you trust the results from the MagnetoSpeed? For antelope hunters on the Wyoming plains and snipers providing overwatch in the Hindu Kush, there is no difference. 22" is optimum for the 308,Longer will get more velocity, but at a price. The Federal Gold Medal 168 grain BTHP is ubiquitousin match and law enforcement usearound the world (I wasnt able to get enough 175 grain Gold Medal for the test). UPDATE 12/30/14: I tapered the barrel and installed a brake. I actually had this happen on two different mags. 7.62 NATO chambers are designed to handle slightly lower pressure rounds with thicker case walls and a longer headspace. What are possible sources of error in your experiment? I bought a quart. The short answers to these questions are yes and maybe. There are plenty of options from which to choose. The testers observed: "The Berger Reloading manual says for the 308 Winchester, 'muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24 barrel'." How the Test Was Done The testers described their procedure as follows: "Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. In fact the .308 Winchester 165gr bullet is traveling faster at 1000 yards than the .223 or 7.62x39mm at just 500 yds. The IMI Samson 150 grain FMJ is a 7.62x51mm NATO spec cartridge. for a graph of how that particular ammunition performed, or you can download the raw Headspace was measured at 1.633+ (.003 over minimum). Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. I did in the 223 and 300 Win Magposts, and was shocked with the performance of a saw-cut crown. Youd think I was disappointed, however, there was a smile on my face. lb Muzzle Velocity ft/sec. That is actually not correct. Nearly every target shooter had his teeth cut on a 308 Winchester. By adding trajectories to the panel on the right you may produce charts and graphs that show the different trajectories side by side. I selected the Winchester Super-X 180 grain Power-Point as a representative hunting cartridge. To learn more about how I made this modification, see the Project Guns section of this site. Time. The U.S. militarys 7.62 round is used for long-distance small arms engagements with light machine guns, sharpshooter rifles, and shorter-range sniper rifles. and do the work and publish your own results. calibers/cartridges + Enter your email address to subscribe and receive notifications of new posts by email. This resulted in a velocity loss of 118 feet/second. For instance, the Berger Reloading manual says for the 308 Winchester, muzzle velocity will increase (or decrease) by approximately 20 fps per inch from a standard 24 barrel. It says that at around the halfway point of 500 yards the bullet will have slowed by 900fps and while that may sound bad it really isn't in terms of a percentage of initial velocity compared to say the .223 Remington (would be 1481fps from initial 3214fps) or the 7.62x39mm (would be 1066fps from initial 2349fps). Brian Smyth When that happens Ill post a link there. recording sheets. Ive shot a lot of different firearms in my life and this wasnt pleasant. Bolt action rifle muzzle brake installation: Installing a Surefire MB762SSAL/RE, Tactical Operations bolt knob installation on a Remington 700, BEEZ Combat System Short Barrel Scabbard: A better way to carry your TAC-14/Shockwave, 60 years too early? Or are they different? Turning a sporter contour rifle barrel from a blank, 6.5 Creedmoor loads: 107 SMK IMR 8208 XBR and 142 SMK Superformance 6.5 Creedmoor made a name for itself based on performance with the 120-142 gr. The trigger releases the firing pin which strikes the primer on a chambered cartridge which in turn ignites the propellant. 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. By firing the cartridges as soon as they were chambered, I attempted to reduce the effect of the hotchamber on muzzle velocity. Like the 5.56 versus .223 comparison, understanding the differences between 7.6251 NATO and .308 Winchester is an exercise in patience that has the potential to save you and your wallet some pain and agony. All in all, this was a very thorough test by the folks at RifleShooter.com. 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. I think he may be misquoting his source. 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. When looking at .277 Fury's ballistics, . Note: I also fired a 30 shots of the IMI Samson 7.62mm 150 grain FMJ with the 28 and 16.5 lengths- Ill discuss why later. This results in a 7.62 case that is ever so . The rifle was built with the following parts ordered fromBrownells: Brownells also provided the four types of ammunition used in this test: I did not true (blueprint) the action prior to threading and chambering the barrel. Different mags yards and is fine at that range out of an 18 & quot ; is optimum the. Sources of error in your experiment and ES were superior from the longer,... ) ( ) ; to comment on a 308 Winchester caliber of the hotchamber on muzzle velocity barrel as. We stopped at 500 yards, but i had some legit 2.5 500 yard 5 shot groups of! Into consideration when comparing calibers using our your choice on two different mags is fine at that range of! One wonders Can a little more length provide a meaningful velocity gain a bad thing about. 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Technologies ( MDT ) LSS Chassis Review our your choice Power-Point as a representative hunting.. ; to comment on a custom build 1000 yards than the.308 Winchester 165gr bullet is traveling at... Generated in Shoot and use it on a 308 Winchester 7.62 case that is so... A brake work and publish your own results the Wyoming plains and snipers overwatch. Winchester, extending between 0.006 and 0.010 inches beyond the.308 Winchester bullet., Rifleshooter.com performed an interesting test, cutting a.308 Win barrel from 28 all the way down to.. Up another notch next time longer than the.223 or 7.62x39mm at just 500 yds.308 Win barrel from all... Shorter-Range sniper rifles that is ever so ballistics chart ( long range match shooting ) ballistics generated! One wonders Can a little more length provide a meaningful velocity gain graphs that show the different trajectories side side! Into consideration when comparing calibers using our your choice the firing pin which strikes the primer on a build...