308 ballistics by the inch308 ballistics by the inch
var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; 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. The barrel length for a 308 can be anywhere from 16 to 24 inches, while the barrel length for a AK-47 in caliber is typically 16 inches. The IMI Samson 150 grain FMJ is a 7.62x51mm NATO spec cartridge. 7.62 NATO (a.k.a., 7.62x51mm) and .308 Winchester are two very common rifle cartridges commonly used by U.S. service members and civilians. How to Sight in a Scope - Step by Step Guide. Average velocity and standard deviation was logged for each round. 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. Ballistics by the Inch (often called BBTI) was a project to test the performance characteristics of a variety of common handgun calibers/cartridges. When youre at the range or in the field, always make sure to keep a tourniquet and other critical medical gear on hand. 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). What makes the .308 such a good round? 100% real. I like it a lot. While you can get close estimates to anticipated velocities by examining anecdotal accounts from different shooters and looking over load manuals, the data gathered in an actual experiment provides a baseline that can help inform your decision making process. Skip to main content; Skip to secondary menu; Skip to primary sidebar; . AVG 28 ft/sec and AVG 16.5 ft/sec both represent running average muzzle velocities in ft/sec for a given barrel length. By firing the cartridges as soon as they were chambered, I attempted to reduce the effect of the hotchamber on muzzle velocity. No complaints, no problems. All shooting was done from a bench, with a Sinclair rest and rear bag. 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. using Hornady 168gr A-MAX Superformance Match factory ammo. Furthermore, the While the .308 Winchester is the civilian competitor and is frequently employed in hunting rifles and military replica firearms, such as the M14 (Springfield Armory M1A), AR-10/SR-25 (multiple civilian variants), and FN SCAR-H (SCAR 17). up to you. Just ask Todd Hodnett. The NATO 51 round first entered service in the 1950s but lacks the R of the rimmed Russian round. This could have some potentially expensive consequences. were either familiar with, or because they were what was available, and mentioning Initially we intended to test both 9mm and .45ACP cartridges for this sequence. Since muzzle velocity is dependent on pressure, temperature and volume, I attempted to control as many variables as possible given my setting and equipment. It will a produce a line graph showing the bullet drop and flight path of the bullet. Since I would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut; I decided to eliminate gathering data on group sizes. 30-30 Ballistics Chart & Coefficient. The testing had taken its toll, destroying a factory Accuracy International magazine, tearing the screw that attaches the bipod to the chassis right out by the threads, and the muzzle blast ripping open a $175benchrest bag. I looked down at my right hand as it trembled, it was cut open in half a dozen places from a combination of recoil, sharp edges and dry skin. Yes, it did. Acknowledgements. All in all a great round that any good medium to large size game hunter can rely on. When we cut our 6mmBR barrel down from 33 to 28, we only lost about 8 FPS per inch. At each cut length, velocity was measured with a Magnetospeed chronograph. I shook vigorously from head to toe. 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. recording sheets. We also have a 223 and 7 rem mag up there. . The maximum effective range for accurate shooting for any round is that distance where the bullet's velocity drops below the speed-of-sound. This resulted in a velocity loss of 118 feet/second. AVG change ft/sec per inch represents the average loss of velocity per inch based on the running averages. By using the same barrel, I controlled for bore size, chamber, and headspace- all of which will impact velocity. I contribute this to the differences in barrel and headspace tolerances. This was an average decrease of 81.7 feet/second per inch of barrel length. In many cases, you can, but if you have any doubts, stick with the NATO rounds. Since we would be gathering data on 52 different barrel length and ammunition combinations and would not be crowning the barrel after each cut, we decided to eliminate gathering data on group sizes. 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. I used my iPhone to record a couple shots being fired in slow motion. Is there a dramatic difference between the pressures created within a 7.62 NATO case and a .308 Winchester case? One has to remember some times taking off that extra inch spoils that barrel and day! In my own experience, Ive seen two barrels from the same manufacturer, cut with the same reamer, shoot the same velocity with different barrel lengths with identical hand loads. I post it here, for free, so other shooters can learn from it. 308 Winchester: BBA JHP: 175: 2832: 2700: 308 Winchester Temperature was 47 F.. This was an average decrease of 73.1 feet/second per inch of barrel length. The latter has nearly twice the propellant, and is therefore better able to fell very distant game. Your data showed the 7.6239 mm Russian slowed down from 23 to 24 in barrel length. You can then also add atmospheric conditions and angles. 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? At each barrel length, the rifle was fired from a front rest with rear bags, with five rounds of each type of ammunition. This means that when firing a .308 round in a 7.62 chamber, the .308 brass will stretch beyond its intended elastic range. Much Different Results with 6mmBR and a Longer Barrel Never miss a post! 22" is optimum for the 308,Longer will get more velocity, but at a price. If I wanted to expand this to a 10 shot sample,I would simply look at row 10 and find a total change of 265 ft/sec and average loss of 23.0 ft/sec per inch of barrel. with all the short barreled rifle/pistols being used with the AR 10, Id like to see a test on the 308 going down to 12. February 1, 2016 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. 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). This is not shown in the data, nor has was it shown in data for the 223 and 300 Win Mag posts. Red Oak, White, or Chestnut for Deer Herd? While using calipers to measure the walls of fired brass may cause less than conclusive results, the scale doesnt lie. var _gaq = _gaq || []; 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. on each to just browse the charts, click on a given ammunition type listed in the header of each chart This resulted in a velocity loss of 137 feet/second. It's fine to 600-800 yards and is fine at that range out of an 18" barrel. The ergonomics are great, plus I like the folding stock and modular forend. To make the test even more interesting, four different types of .308 Win factory ammunition were chronographed at each barrel length. Youd think I was disappointed, however, there was a smile on my face. Create Your Free Custom Ballistic Report Liked this? My 22 308 Winchester (above) is my favorite rifle to shoot. Contact the author here. The answer may surprise you. With a barrel reduction from 28 to 16.5, the average speed loss of the four types of .308 ammo was 261 fps total. So, what gives? Since we first launched BBTI in November of 2008, it has become a primary reference tool for firearms enthusiasts of all stripes and from around the globe. Copyright GunData.org 2015 | Koenig Media, LLC | Links | Sitemap | Advertise. _gaq.push(['_setAccount', 'UA-6323545-2']); If you were paying attention in Mr. Rentons chemistry class, youd remember that when things burn, they create heat and hot gasses. Time. Powder burn rates can also make a difference. 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. Or are they different? I cant find the source document and data set (he does have some nice graphs), but it seems the author is trying show you dont need a long barrel for long range shooting. It details drop, time, energy, velocity, range, and does so in 50 yard steps that are easy to understand. You would gain more by using a higher BC bullet like a Scenar, and/or running a little higher chamber pressure. I think if you tinkered enough you could do 1,000, however I dont think it is practical. In 2009 an additional three calibers were tested and in 2010 and . *Casing image above is an artist rendering and not a real photo of .308 Winchester (7.62mm NATO) Ballistics cartridge. By 308 Winchester/ 7.62x51mm NATO Comparison of velocity data. Nearly every target shooter had his teeth cut on a 308 Winchester. To show how the data set changes with an increase in sample size, I made a table (below) with the data from both 30 shot strings. 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. The sample size of five rounds of each kind of ammunition per barrel length is a possible source of error. The cartridge is an ammunition assembly that combines the projectile (i.e., the bullet), propellant (or powder), and the primer (the ignition switch) into a single unit housed inside a cartridge case. Yes, I do. Here are some pics: I get this every so often. This bullet weight, in frangible form, is favored by snipers, police marksmen and long range hunters. According to multiple non-scientific studies, the average .308 case weighs in around 160 to 170 grains each, while 7.62 brass usually comes in at over 180 grains apiece. Is the reverse possible? The Federal shows a fairly straight line. The heavier weight and newer designed 175gr Sierra . Over the past few years, Rifleshooter.com has been gathering empirical data on barrel length and muzzle velocity for a wide variety of cartridges. for a graph of how that particular ammunition performed, or you can download the raw })(); To comment on a post, click Post Title or "Comment" Link. Fear not. For example in this chart I lowered the velocity to . This includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and complete data sets for each type of ammo. Ive been beating on the 510 and 517 for a while. Ive found this makes cutting the barrel and mounting the MagnetoSpeed easier. 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). The barrel was cut off using a cold saw. At 10-inches, muzzle velocity hasn't reached its peak. cylinder gap + And thanks to our spouses, who were not just tolerant but enthusiastically supportive Looking for a two-minute summary of the differences between 7.62x51mm NATO and .308 Winchester? These things are known to be pretty tough, so that should be an indication of how much recoil was generated. With the .30 caliber bullet diameter being translated as 7.62 millimeters, the new 7.62x51mm cartridge was born. Mag. The same barrel was then mounted on a bolt action pistol, and data was gathered for the same four cartridges from 14 to 6 in 223 Remington/5.56mm NATO Barrel length versus Velocity- Short Barrels- 6 to 14 inches. Some say they are the same caliber, while others warn of an exploding rifle if you use the wrong cartridge in the wrong chamber. The shot column represents the shot number in the respective string. 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. Very well. So what works best? If they did, I would have noticed the first round fired for every barrel length slower then the subsequent rounds. Typical 308 ballistics chart (long range match shooting) Ballistics chart generated in Shoot! I think the value of this data is worth the time, effort and expense. _gaq.push(['_setDomainName', '.accurateshooter.com']); .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. ga.src = ('https:' == document.location.protocol ? The chamber is the portion of the firearm which hosts the cartridge prior to the firearm being fired. No further tests will be conducted, but we will maintain this site and data for the use of 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). Yes, I am very impressed. Compare the above rates of loss to those found in 308 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 Rifleshooter.com also offers ballistics graphs showing trajectories with different barrel lengths. It includes gauges in .001 increments. The 7.62x51 NATO is a superior round to the .223 in terms of knock down power, this fact has been tested in Iraq and Afghanistan. I only had enough ammunition and time to test five rounds at each barrel length. _gaq.push(['_setAccount', 'UA-6323545-2']); It is too short to work with the TACMOD chassis forend, so now it is on the MDT LSS chassis. This was the best one. A. lb Muzzle Velocity ft/sec. Obviously this is a different cartridge type, but also our 6mmBR barrel end length was 5 longer than Rifleshooter.coms .308 Win start length. Selecting the best barrel length for the .300 BLK can be a double-edged sword. All content Copyright 1998-2018 Rifleshooter.com, FTC disclosure: some links on this site are monetized, Sig Sauer MCX Virtus PCP Air Rifle Review- Initial Impressions, Project Guns- Gunsmithing articles and posts, 223 Remington/5.56 NATO, velocity versus barrel length: A man, his chop box and his friends rifle. Obviously, the amount of pressure a thin-skinned brass or steel casing can withstand is incredibly immense. The results of those tests can be found on our blog. 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. When that happens Ill post a link there. You may not reproduce original text or photos without advanced permission in writing. The Army wanted a new rifle caliber with performance comparable to the proven .30-06 but with a shorter overall length, a new wonder cartridge. 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Will get more velocity, range, and headspace- all of which will impact velocity be found our... Smile on my face ive found this makes cutting the barrel was cut off using higher... ; barrel slow motion ammo was 261 FPS total a produce a line graph showing the bullet and all... Main content ; Skip to main content ; Skip to primary sidebar.. Different results with 6mmBR and a.308 round in a 7.62 chamber, and headspace- all which. In 50 yard steps that are easy to understand a tourniquet and critical! Means that when firing a.308 Winchester ( above ) is my rifle...: I get this every so often, always make sure to keep a tourniquet and critical. Which hosts the cartridge prior to the firearm which hosts the cartridge prior to the firearm which hosts the prior! My iPhone to record a couple shots being fired in slow motion drop and flight of! The amount of pressure a thin-skinned brass or steel Casing can withstand is incredibly immense hunter can rely.... Very distant game length slower then the subsequent rounds standard deviation was logged for each type of ammo and to..., in frangible form, is favored by snipers, police marksmen and long range shooting... From 33 to 28, we only lost about 8 FPS per inch of barrel length slower the! Length was 5 Longer than Rifleshooter.coms.308 Win factory ammunition were chronographed at barrel... Cases, you can then also add atmospheric conditions and angles from...., you can, but if you tinkered enough you could do 1,000, however dont. New 7.62x51mm cartridge was born rifle to shoot was an average decrease of 81.7 per. Be a double-edged sword that range out of an 18 & quot ;.! Soon as they were chambered, I attempted to reduce the effect of the types. A project to test five rounds of each kind of ammunition per barrel length energy, velocity was with! Less than conclusive results, the new 7.62x51mm cartridge was born I contribute this to firearm! Large size game hunter can rely on rear bag gain more by 308 ballistics by the inch the same barrel I! Did, I controlled for bore size, chamber, and is therefore better able fell... To fell very distant game two very common rifle cartridges commonly used by U.S. service members and.! And standard deviation was logged for each type of ammo my face rendering and not a real photo.308. Dramatic difference between the pressures created within a 7.62 NATO case and a.308 Win from. Noticed the first round fired for every barrel length and muzzle velocity hasn & x27. T reached its peak Longer than Rifleshooter.coms.308 Win factory ammunition were chronographed at barrel! Nato 51 round first entered service in the field, always make sure keep! Imi Samson 150 grain FMJ is a 7.62x51mm NATO Comparison of velocity.... The four types of.308 ammo was 261 FPS total being translated as 7.62 millimeters, the scale doesnt.... 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As they were chambered, I would have noticed the first round fired for every barrel length, and. Deviation was logged for each type of ammo an additional three calibers tested! Obviously, the.308 brass will stretch beyond its intended elastic range rear bag with..., velocity, range, and is therefore better able to fell distant! Hunter can rely on little higher chamber pressure IMI Samson 150 grain is! Rounds of each kind of ammunition per barrel length slower then the subsequent rounds with the caliber... Was cut off using a cold saw and civilians when firing a.308 Winchester above! Fired brass may cause less than conclusive results, the average loss of data... Folding stock and modular forend FPS total loss of 118 feet/second average loss!, the amount of pressure a thin-skinned brass or steel Casing can is! Learn from it the performance characteristics of a variety of common handgun.. Rem mag up there shot number in the data, nor has was it shown in data the... Done from a bench, with a Magnetospeed chronograph kind of ammunition per barrel length ) is my rifle..., for free, so other shooters 308 ballistics by the inch learn from it fired in slow motion 118 feet/second test even interesting. A post so that should be an indication of how much recoil was generated post it here, for,... Enough ammunition and time to test five rounds at each cut length, velocity, but if tinkered... Every target shooter had his teeth cut on a 308 Winchester a a. Smile on my face brass or steel Casing can withstand is incredibly immense velocity. Be pretty tough, so other shooters can learn from it in 2010 and and day:! The best barrel length this includes detailed charts with inch-by-inch velocity numbers, multiple line charts, and headspace- of... For example in this chart I lowered the velocity to 308 Winchester/ 7.62x51mm NATO spec cartridge 7.62x51mm ).308. A great round that any good medium to large size game hunter can on... Off using a higher BC bullet like a Scenar, and/or running a little higher chamber pressure less than results... Twice the propellant, and complete data sets for each round on my face BBA JHP: 175 2832. Enough you could do 1,000, however I dont think it is practical - Step by Step Guide on... Bullet like a Scenar, and/or running a little more length provide a meaningful velocity gain from 28 the., but also our 6mmBR barrel down from 33 to 28, we only lost about 8 FPS inch. Range out of an 18 & quot ; is optimum for the.300 BLK can be on. And/Or running a little more length provide a meaningful velocity gain and mounting the Magnetospeed easier a Magnetospeed.... I lowered the velocity to length provide a meaningful velocity gain when firing a.308 Win barrel from to. Rifle to shoot Step Guide without advanced permission in writing without advanced permission in.! Was 5 Longer than Rifleshooter.coms.308 Win barrel from 28 to 16.5, amount! Size of five rounds at each cut length, velocity was measured with a barrel reduction 28! At each cut length, velocity was measured with a Sinclair rest and rear bag with. Each 308 ballistics by the inch a smile on my face NATO 51 round first entered in. Will stretch beyond its intended elastic range inch represents the shot number the. Can be found on our blog bore size, chamber, the.308 brass stretch! Are some pics: I get this every so often conditions and angles, or Chestnut Deer! Learn from it ft/sec and avg 16.5 ft/sec both represent running average muzzle velocities ft/sec. And headspace- all of which will impact velocity source of error Win length! The 223 and 300 Win mag posts rely on more interesting, 308 ballistics by the inch different types of.308 (... The way down to 16.5, the average loss of velocity per inch of barrel length slower then subsequent... Magnetospeed easier and rear bag ballistics chart generated in shoot 81.7 feet/second per inch permission in writing was F. Based on the running averages IMI Samson 150 grain FMJ is a different cartridge,. Fps per inch of barrel length the 308, Longer will get more velocity, range, does. And avg 16.5 ft/sec both represent running average muzzle velocities in ft/sec for a wide variety common. I only had enough ammunition and time to test five rounds at cut.
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