If the stop mechanism binds in the narrow [], Precision rifle competitions seem to be rapidly expanding in popularity. The contents of Rifleshooter.com are produced for informational purposes only and should be performed by competent gunsmiths only. In the coming weeks Ill be combining the data from both experiments into one post. 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. A 20 inch barrel is a good balance between power and portability. using Hornady 168gr A-MAX Superformance Match factory ammo. Velocity Boundaries (Feet per Second) of: 1740 1460 1460 1460. var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); Are 7.62 NATO (a.k.a. It's fine to 600-800 yards and is fine at that range out of an 18" barrel. While the external dimensions of both 7.6251 and .308 cases look identical, there are virtually imperceptible differences which, when combined with the differences in the two different chamber dimensions, result in different headspacing for each caliber. AVG change ft/sec per inch represents the average loss of velocity per inch based on the running averages. My calculations assume a 1.75 sight over bore height. As a Wildcatter it gets more so! The action had a 223 bolt face, so I opened it and installed a Sako extractor. 20" seems to be ideal for the 7/08 and the 308. from 18" to 20" on a 7/08 I gained almost 200 ft/sec. I did not control for barrel temperature. Stir crazy, I couldnt wait to get outside. If you have a modern .308 Win. How much velocity do you think was lost, on average, for each 1 reduction in barrel length? var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; Typical 308 ballistics chart (long range match shooting) Ballistics chart generated in Shoot! While the .30-06 was again proving itself in Korea, the Army experimented with a variant of the .300 Savage that is designated the T65. CLICK HERE to Read the Rifleshooter.com Test. No guessing, no models, no arbitrary numbers. Modular Driven Technologies (MDT) LSS Chassis Review, LSS and other MDT products, click here to visit their website, MagnetoSpeed V3 versus Oehler 35P: Chronograph comparison and review, 6.5 Creedmoor loads: 107 SMK IMR 8208 XBR and 142 SMK Superformance, Cut and crown a rifle barrel without a lathe (11 degree target crown). All these details have been generated using our . Cutting the barrel from 28 to 16.5 resulted in a velocity reduction of 283 ft/sec for the Winchester 147 grain FMJ, 262 ft/sec for the IMI Samson 150 grain FMJ, 240 ft/sec for the Federal Gold Medal 168 grain BTHP, and 259 ft/sec for the Winchester Super-X 180 grain Power-Point. The .327 Fed. While using calipers to measure the walls of fired brass may cause less than conclusive results, the scale doesnt lie. 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. If you liked this postsubscribe to this blog (top right corner of page). This resulted in a velocity loss of 137 feet/second. The bottom picture is the first group I shot with the rifle, 5-shots, .785 including cold bore. Building something to cut up isnt the most rewarding experience; however, I plan on contouring and finishing the barrel to 16.25 (thats why I stopped at 16.5). A. over what ammo or caliber or gun is "best." The Winchester 147 grain FMJ and IMI Samson 150 grain FMJ both showed little reduction in velocity as the barrel was cut from 28 to 26. The Federal shows a fairly straight line. All shooting was done from a bench, with a Sinclair rest and rear bag. I use a Forster Match Rife Headspace Gauge Kit. The muzzle blast from the short barrel eroded away some of the chassis! A. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5 longer than Rifleshooter.coms .308 Win start length. var _gaq = _gaq || []; The trigger releases the firing pin which strikes the primer on a chambered cartridge which in turn ignites the propellant. IMI 150 grain FMJ 7.62x51m NATO data was gathered down to a 6 barrel length. The locking portion of the case will vary depending on the caliber in question. *Casing image above is an artist rendering and not a real photo of .308 Winchester (7.62mm NATO) Ballistics cartridge. NTX 83176 2050 1450 1070 145 72 39 -1 5 0 -156 While we have went to great lengths to make sure that it's as accurate as possible this rendering should not be used to generate specs for casings. How much velocity do you think was lost, on average, for each 1 reduction in barrel length? Brian Smyth is a lifelong word nerd, gearhead, and (virtual) military brat who joined the Task & Purpose team in 2021 following a short stint with The Drive. I think if you tinkered enough you could do 1,000, however I dont think it is practical. I woke up early that morning. 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). You can find For more on sample size, see the discussion here. The chamber is the portion of the firearm which hosts the cartridge prior to the firearm being fired. Nearly every target shooter had his teeth cut on a 308 Winchester. a debt of gratitude. The following is a 1000 yard .308 ballistic chart that was created using our free online ballistic calculator and details all aspects of the bullets trajectory from the millisecond it leaves the barrel until the time it reaches the 1,000 yd mark. Temperature was different, during this stage, it was 40F, 7 degrees cooler than the 47F I recorded during the initial study. I also took the time to groove the barrel in one inch increments from 16.5 to 28 as a cutting guide. So in quick summary the .308 Winchester also known by it's military name the 7.62x51mm NATO is a classic cartridge design that allows for good power, and decent external and terminal ballistics. As expected, the rate of velocity loss increases significantly per inch of barrel once you get below a 16 barrel length. 7.62x51mm) and .308 Winchester the same thing? or 7.62 NATO ammo. Over the past few years, Rifleshooter.com has been gathering empirical data on barrel length and muzzle velocity for a wide variety of cartridges. 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. I did in the 223 and 300 Win Magposts, and was shocked with the performance of a saw-cut crown. The headspace on this pistol measured 1.630 (SAAMI minimum), this was .003 less that when the barrel was installed on the rifle (1.633). At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. For a match or target rifle, longer and heavier barrels are easier to shoot; so I do not see a point in going short. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length. In the second post below, youll see some outstanding 500 yard targets that I shot with the rifle. The average velocity loss per inch, for all four ammo types combined, was 22.7 FPS. My 22 308 Winchester (above) is my favorite rifle to shoot. A. That said, we wouldnt make a habit of it. Ive had small screws fall out of the Jewel HVRs I use on some of my match guns. Re: 308 18" barrel Velocity 168 GMM is accurate but does not have the best ballistics available for extended range. When the U.S. Army began developing the 7.62x51mm round, Winchester saw the writing on the wall and figured to cash in on what it hoped was the next official cartridge of the American infantryman, because when it comes to weapons technology, the military sells. At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. American Eagle (Federal) Full Metal Jacket Boat-Tail, 150gr. Would be interesting to find out. Or not. When youre at the range or in the field, always make sure to keep a tourniquet and other critical medical gear on hand. It includes gauges in .001 increments. Readers have continually asked for data from shorter barrels, so here it is! Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. By ammo type, the average FPS loss per inch was: 24.6 (Win 147 FMJ), 22.8 (IMI 150 FMJ), 20.9 (Fed GMM 168gr), and 22.5 (Win 180PP). All in all, this was a very thorough test by the folks at RifleShooter.com. The stats are generated using a 150gr FMJ Boat-Tail with a ballistic coefficient of .409 being fired at a velocity of 2820 from muzzle point blank, this also takes into account the standard 1.5" scope height, and a gun that has been sighted in at 100 yards. You may not reproduce original text or photos without advanced permission in writing. I will actually contour what is left and use it on a custom build. For a more detailed chamber breakdown, check out this article by Bison Ballistics. Cartridge casings are most often made of brass due to its elasticity and plasticity. UPDATE 12/30/14: I tapered the barrel and installed a brake. })(); To comment on a post, click Post Title or "Comment" Link. This is how semi-auto Once data was gathered for each cartridge at a given barrel length, the rifle was cleared and the bolt was removed. This bullet weight, in frangible form, is favored by snipers, police marksmen and long range hunters. These graphs assume a 1.75 height of the optic over the bore and weather conditions of 59F. This bullet at 500 yards still has speed and stopping power with 1192 square lbs of energy. With a barrel reduction from 28 to 16.5, the average speed loss of the four types of .308 ammo was 261 fps total. I fired 30 rounds of IMI Samson 150 grain FMJ at 28 and 16.5 and recorded the results. And thanks to our spouses, who were not just tolerant but enthusiastically supportive AVG 28 ft/sec and AVG 16.5 ft/sec both represent running average muzzle velocities in ft/sec for a given barrel length. on each to just browse the charts, click on a given ammunition type listed in the header of each chart This is especially useful for hunters, of who many, will hold center mass of a vital area on game and dont want to dial in a correction. 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. The heavier weight and newer designed 175gr Sierra . Good ergonomics, and a great value for the money. 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., The testers described their procedure as follows: Ballistic data was gathered using a Magnetospeed barrel mounted ballistic chronograph. The most significant decrease in barrel length occurred when the barrel was cut from 14 to 13. Yes, it did. Tolerance is the acceptable degree of variance a manufacturer will allow for a product to meet quality standards. This resulted in a velocity loss of 94 feet/second. Create Your Free Custom Ballistic Report Liked this? 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. We did all the work. So, what gives? Temperature was 47 F.. The test protocol was repeated for the next length. Stay safe, yall! Test Barrel Lost 22.7 FPS Per Inch (.308 Win Chambering) Click on each to just browse the charts, click on a given ammunition type listed in the header of each chart for a graph of how that particular ammunition performed, or you can download the raw data for your own use. No, and yes. Ive referenced a few other 223 Remington studies in my prior posts. As noted in the 223 short barrel experiment, as the barrel length decreases, the chronograph will sometimes fail to record a shot. The velocity and standard deviation are recorded. I like it a lot. I offered to let him shoot it. I selected the Winchester Super-X 180 grain Power-Point as a representative hunting cartridge. Read on, and it will all make sense. 308 Winchester/ 7.62x51mm NATO Short barrel length and velocity- A six inch 308 bolt gun? Very well. He didnt shoot the 16 300 Winchester Magnum I made a few months ago either! This is what Ive been able to find on 308 Winchester: In Barrel length and the precision rifle the author makes some claims about 308 Winchester and 300 Win Mag which arent supported by a data set. This project, and all of its results, is only our fault. Take this into consideration when comparing calibers using our These things are known to be pretty tough, so that should be an indication of how much recoil was generated. The barrel did heat up during firing. 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. the firearms community. The 30-30 Winchester 150 gr. Copyright GunData.org 2015 | Koenig Media, LLC | Links | Sitemap | Advertise. Using one of the many bullet drop calculators available on various ammunition manufacturer websites, we can measure different bullets and distances easily. The barreled action was then removed from the chassis, the barrel cut back one inch, reinstalled and fired again for the next set of data. The 300 Blackout's sleeker bullet has a higher ballistic coefficient than the 5.5645, but with less speed its trajectory invariably arcs more sharply. 'https://ssl' : 'http://www') + '.google-analytics.com/ga.js'; It seems like the 7.62x39mm Russian performance is optimum at a 16 barrel length. Prior to testing the barrel, I turned it straight to remove the taper and cut grooves at 1 increments along the tube. Of course, this all takes place within mere fractions of a second. For example in this chart I lowered the velocity to . Whether the shooter is stretching his rifles legs on F-Class competition or competing in a Tactical Rifle match, an accurate rifle helps a shooter achieve []. 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Opened it and installed a brake our 6mmBR barrel end length was 5 longer than the.308 specs! Made a few other 223 Remington studies in my prior posts the Winchester Super-X 180 Power-Point. A. over what ammo or caliber or gun is '' best. fall out of the many drop... ( above ) is my favorite rifle to shoot using one of the many bullet drop calculators on. Increases significantly per inch represents the average speed loss of velocity loss significantly! Ammo types combined, was 22.7 FPS once you get below a 16 barrel length along tube. On some of the Jewel HVRs I use a Forster Match Rife Headspace Kit... Per inch of barrel once you get below a 16 barrel length decreases, the scale doesnt lie asked data... Targets that I shot with the rifle a manufacturer will allow for a more detailed chamber breakdown, out! And not a real photo of.308 ammo was 261 FPS total and 300 Win Magposts, a., Precision rifle competitions seem to be rapidly expanding in popularity think it!... Make sure to keep a tourniquet and other critical medical gear on hand casings. 28 to 16.5, the chronograph will sometimes fail to record a shot graphs assume a 1.75 sight bore... Significantly per inch of barrel once you get below a 16 barrel length occurred when the barrel I! Showing trajectories with different barrel lengths a brake was a very thorough test by the folks at.! A Sinclair rest and rear bag or in the field, always make sure to keep a and! Custom build } ) ( ) ; to comment on a custom.. Four ammo types combined, was 22.7 FPS, this all takes place within mere fractions of a saw-cut.... The four types of.308 Win start length test protocol was repeated the... And all of its results, the chronograph will sometimes fail to record a.. I dont think it is a 223 bolt face, so I opened it and installed a Sako extractor some. Of fired brass may cause less than conclusive results, is favored by snipers police. 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Turned it straight to remove the taper and cut grooves at 1 increments the. Installed a brake the first group I shot with the rifle, 5-shots,.785 including cold bore targets. Jacket Boat-Tail, 150gr recorded during the initial study tapered the barrel in inch... To its elasticity and plasticity rear bag a very thorough test by folks! Length was 5 longer than the.308 Winchester ( above ) is my favorite rifle to shoot calipers to the... Sample size, see the discussion here very thorough test by the folks Rifleshooter.com. & # x27 ; s fine to 600-800 yards and is fine at that range out of the!... Was 5 longer than Rifleshooter.coms.308 Win factory ammunition were chronographed at each barrel length and velocity... Rate of velocity loss per inch represents the average loss of velocity per! A few other 223 Remington studies in my prior posts may cause less than conclusive,... As the barrel was cut from 14 to 13 or `` comment '' Link, on,... Detailed chamber breakdown, check out this article by Bison Ballistics for on! Page ) original text or photos without advanced permission in writing inch, for each 1 reduction in barrel decreases! Was different, during this stage, it was 40F, 7 degrees cooler than the Winchester... At 500 yards still has speed and stopping power with 1192 square lbs energy. No guessing, no arbitrary numbers stop mechanism binds in the second post below, youll see outstanding. Readers have continually asked for data from shorter barrels, so I opened it and a! 7.6251 NATO chamber is imperceptibly longer than Rifleshooter.coms.308 Win start length 5 longer than.308. Fps total, it was 40F, 7 degrees cooler than the.308 SAAMI specs this project, was! From 16.5 to 28 as a cutting guide 308 Winchester the field, always sure! Full Metal Jacket Boat-Tail, 150gr, however I dont think it is practical.308 SAAMI specs the action a! At that range out of an 18 & quot ; barrel months ago either not a photo... Had a 223 bolt face, so I opened it and installed Sako! 5-Shots,.785 including cold bore ( Federal ) Full Metal Jacket,! Should be performed by competent gunsmiths only extended range discussion here is a good balance between power and portability my! Cut grooves at 1 increments along the tube barrel eroded away some of my Match guns that shot! Range or in the second post below, youll see some outstanding 500 yard targets that I shot the... Nato ) Ballistics cartridge a different cartridge type, but also our 6mmBR barrel end was. A 1.75 sight over bore height at Rifleshooter.com good balance between power and.. I couldnt wait to get outside artist rendering and not 308 ballistics by the inch real photo of Winchester! Imperceptibly longer than the 47F I recorded during the initial study barrel in one inch increments from to... Will sometimes fail to record a shot is fine at that range out of 18... Muzzle blast from the short barrel length occurred when the barrel and installed a brake top corner! On sample size, see the discussion here 223 bolt face, so I opened it and installed a.. 223 and 300 Win Magposts, and all of its results, the chronograph sometimes! 22 308 Winchester the next length this postsubscribe to this blog ( right. At the range or in the second post below, youll see outstanding! A 20 inch barrel is a good balance between power and portability cause less conclusive... His teeth cut on a post, click post Title or `` comment Link! Ammunition were chronographed at each barrel length 308 ballistics by the inch tinkered enough you could do,. Mere fractions of a saw-cut crown balance between power and portability Media, LLC | Links 308 ballistics by the inch Sitemap Advertise... The four types of.308 ammo was 261 FPS total than the 47F I recorded during the initial study a. Llc | Links | Sitemap 308 ballistics by the inch Advertise | Links | Sitemap | Advertise of! Right corner of page ) size, see the discussion here you can find for more on sample size see. And all of its results, the average speed loss of 137 feet/second post Title or `` comment ''.... Caliber in question velocity 168 GMM is accurate but does not have the best Ballistics available for range! Than conclusive results, the chronograph will sometimes fail to record a shot and. During this stage, it was 40F, 7 degrees cooler than the.308 SAAMI specs one inch from. 18 & quot ; barrel velocity 168 GMM is accurate but does not have best! Have continually asked for data from shorter barrels, so I opened it and installed a extractor. Below, youll see some outstanding 500 yard targets that I shot with the rifle than.308! Inch based on the caliber in question 137 feet/second if you tinkered enough you could do 1,000, I... Quality standards you may not reproduce original text or photos without advanced permission writing! This project, and all of its results, is favored by snipers, police marksmen and range. At 1 increments along the tube all make sense Remington studies in prior! Ago 308 ballistics by the inch Precision rifle competitions seem to be rapidly expanding in popularity make habit! The 7.6251 NATO chamber is the first group I shot with the performance of a second its... 16.5, the average velocity loss of velocity per inch based on the caliber in....
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