@@jhutch1470 Stryker: 300 AAC Blackout 147 Gr. - 200 Rounds Description: Stryker 300 AAC Blackout ammunition consists of Lake City brass, boxer-primers and projectiles. Designed for medium range target practice, training and plinking. This line of ammunition is 100% American made. All of our 300 BLK ammunition is tested for function using an AR-15 style pistol with a 10.5" barrel and pistol length gas system. Muzzle Velocity (FPS) - 1,730 Muzzle Energy (lbs.) - 977 ft. This is budget ammo and puts out 1730 from a 10.5. I run 110-124gr usually Hornady black, or L-tech solid copper. Thos number above were from memory when I used to chrono different loads. I chronoed some 124gr copper from L-tech yesterday and was at 2078, and the hornady 110gr was 2130.
@@eddiearchuleta615 I have watched quite of few of Buffmans videos where he chronos many 223/5.56 ammunition. All I can say is that there seems to be no exact standard and not all ammunition is equal. Most M193 should hit 3100 fps from a 20" barrel. From tests I've seen, Federal or AE M193 and Winchester M193 is usually loaded pretty hot and hits that 3100 fps or above. However, speed isn't everything. Some of the higher velocity loads can't group for worth a damn. Boils down to that happy medium of speed and accuracy from that particular rifle. Some are okay with getting 2-3" groups. Others want that MOA or sub MOA groups no matter what.
@@davisw13 From what I've seen, the PMC X-Tac is slower than other M193 ammunition. But speed isn't everything, depends on what expectations the shooter has and how that ammo performs in their particular rifle in terms of reliability and accuracy. I myself don't care too much about the velocity of the ammo as much as I do about how well it feeds and what kind of groups my rifle can make with it. If it's reliable and gives me groups of 2" or less, I'll take it. More than 2", it's strictly limited to the range until the ammo is gone or I try it in a different gun. Everyone's milage will vary.
@@kaweka260 got one about a year ago. I’ve put about 1000 rounds through it and never had a malfunction that wasn’t my own fault. It’s a one and a half MOA gun with good ammo. 2 MOA with cheap Winchester or PMC green tips. Absolutely a good enough AR pistol.
Try the 14.5 Geissele URGI with the mid-length gas system. I’d be interested to see the velocity vs the 12.5. I’ve also seen manufactures now offering a 13.7, maybe throw that in the mix. ✌️
The Daniel Defense 14.5 is a carbine gas length, while the IWI 12.5 is surprisingly a mid length. That means the 12.5 had more distance of pure push before diverting forces into the gas system.
the 18" is just better. its long but its not that much longer to get all the benefit of the rifle systems.. and not to say how the shorter the gun the harder it is on the internal parts
I don't believe the gas system has any major effects in this testing. There was a test done years ago where someone designed a jig with a barrel that has pressure sensors at every inch to measure the 5.56 pressure curve when fired. It mimicked these results exactly. It showed that the powder mixture did not burn at an even rate and would have distinct repeatable pressure spikes at different barrel lengths. The largest spike was roughly at the12" barrel length where it would then stay flat until around 16" where it would see another small spike so essentially anything under 16" would have little to no variation in velocity. If I remember correctly the most important spikes for velocity boosts where around 12",16" and then either 20" or 22" can't exactly remember the last one.
@@MRsolidcolor Not that much longer? Try the 2 when your in a vehicle. I stick with 10.5. It loses about less then 150 over the 12 but 2 inches even makes a difference if you are in and ouf of a vehicle. If not, 12.5-14.5 gets the job done.
- Gas port size (timing and some pressure leakage) - Barrel tolerance (gas leak to friction) - Twist rate (small changes but more twist more work...) - Propellant burn rate
And let's not forget some barrels have a tapered boar such as Centurion, Hodge, and I believe FN as well, which will give better velocity than a non-tapered bore
@@CoryHobbs2178every single CHF barrel has a slightly tapered bore. Otherwise the mandrel would stick during forging. Every single CHF barrel is made on the same company machine GFM
Agreed! I love shooting my RUG AR 18". Though admittedly my shoulder accuracy is awful, bipod necessary past 100 yards! Can't complain about rounds hitting great from 55g-77g either! Slightly stiffer spring with H1 buffer really took the recoil too!
So for explaining the 12.5" vs 14.5" question: 1) gas system length 2) gas port size 3) twist rate 1:8 vs 1:7 with bullet type 55gr 4) nitride vs chrome line barrel
Actually it is the ft lbs that does the atrocity. The force that the projectile hits a body. That force is a combination of the velocity and the weight. Like if I tossed a .50BMG bullet at you from 10 yes you would be pissed but if I used a sling shot you might need stiches.
I've read the 12.5 vs 14.5 debate way back and I always found it super interesting. I recall reading an article years back of someone doing a test with a special barrel that had removable bits every inch and pressure sensors on each inch to measure the 5.56 pressure curve at each inch of barrel which was very impressive. It showed that there was a major pressure bump right around the 12" section and then smaller bumps around the 16" and 20" marks if I recall correct. I remember taking away that personally 11.5" was the shortest I'd go for 5.56 and 12.5 performed the same as anything below 16" I think the most notable person to mention this was the late former head of Noveske. Sorry I don't remember his name but he did a video with someone talking about why he believed the 12.5 was the best all around barrel length for a do all rifle.
My ideal setup is a 12.5" registered SBR with a compact stock, a Sandman-K suppressor, a 1-6 lpvo, and a Cloud Rein. Small and light, but still capable at decent range. If I could have only 2 rifles I'd have that, and a magnum bolt gun for long distance/heavy hitting.
@@Kross8761 jesus. You literally described my current setup exactly. Haha! I am a guy that is always on the fence about his setup, so it’s nice to see a like mind. I will be swapping my rein with an OKW because I have some special use testing on duty that I have preferred it for, but the rein will just be repurposed. Its a great light. Oh, and my Sandman K will be replaced by a Sierra 5 but both are amazing.
@@dubjspecialk the main reason I like the sandman is just so that I can use it on my hunting rifle also to take a little bit of the "bite" out of it with only one suppressor. I don't have a lot of money for multiple suppressors so I try to multitask as much as is practical.
Yeah. The more consistent and high quality a barrel's production, generally the higher velocity you'll get. the gas port is negligible if you have one at all
That's what I was going to ask. I can't imagine the length of barrel past the gas port being that much different that it would cause this. The next question on this is what are the groups at 100 yards? I'm betting there would be a significant different between the 12.5, 14.5 and the 16, likely with a dip in the 14 inch.
I think the problem is the gas system lenght, ZION has - MID lenght - gas system, DD M4A1 has - CARBINE lenght - info avaliable on manufacturer's page With the mid lenght, the bullet have more time accelerating until gas starts to leak to operate the action. that's my tought
Great test. I see about the same difference between 16" and 20" myself. I did a quick calculation on Quickload if you are interested. I started with what charge it took to get a 55g bullet to match at 20" and worked down to 7.5" Barrel length / Clint's test / QuickLoad prediction 7.5" / 2183 / 2219 10.3"/ 2513 / 2520 11.8"/ 2644 / 2639 12.5"/ 2789 / 2688 14.5"/ 2763 / 2809 16.0"/ 2872 / 2887 18.0"/ 2998 / 2976 20.0"/ 3052 / 3052
Just built mine with a 10.3 in barrel. Depends on what you intend for it to be used as but the guys at Ballistic Advantage highly recommended the 10.3 which is why I went that route.
FYI. 5.56 manufacture velocity is normally from a 20" barrel. .223 Manufacturer velocity is normally from a 24" barrel. One was designed as the military round for a 20" barrel. The other was designated as a hunting round. Almost all "hunting" round velocities are from a 24" barrel. Also not all ammo is created equal. Some 5.56 ammo is not loaded to Mil Spec and some are
Right also mass production twist rate change etc etc all affect what we see. If they are using the same ammo for every barrel that's going to affect the test
@@serenmm … indeed!! A neutral test would be using one manufacturer’s equipment for true varied barrel length speed differences. Classic Firearms def is not about neutral but subjective … which brings out the fiery comments … part of the channel’s design 😅
I was thrown off too when he kept saying 24”. I knew it should have been 20”. Also I was surprised he didn’t use surplus ammo for this test. Seemed like a lot of work to just leave out such a large component like federal ammo / lake city.
Your differences on the 12.5 seems to have more variation than the others. I think you should’ve shot another group out of the 12.5. Your 1st shot was 100 fps faster than the slowest in the 12.5 group
I’ve already done this test and I went with 11.5” pistol length and 18” rifle length. I went 20” on my AR 10 and 6.5 Grendel but have not tested shorter barrels for these two. The 7.5” AR 15 looses too much velocity to be useful and is absolutely annoying to anyone nearby.
Not the Springfield. It pushes forwards and not sideways. It will loose velocity which is why the 1:7 twist needs a heavier grain round. So atleast you get the punch… oh and I run .223
this is a long awaited video for me thanks for doing it. you could go one better by doing the same thing with 55 grain and 62 grain bullets. will the shorter barrel guns do a little better as far as the the velocity spread difference between the barrel lengths using 55 grain bullets? could the heavier bullets have the same affect as a suppressor? anyway thanks for the video very good.
Just got the IWI 12.5 inch. Made my decision easy with all the great info in previous videos and this confirms to me that it may be the best option for the price.
If you mic the fired cases, I bet you'll find the ones from the "slow" gun are larger, indicating more generous chamber dimensions. The pressure needed to obturate the brass to fill the chamber takes away from what is available to drive the bullet. Tighter chambers will be "faster", all other things being equal, but they are undesirable in a battle rifle because it takes very little fouling or dirt to cause the firearm to fail to chamber a round.
What this test shows is that PMC 5.56 is not actually 5.56. Looks like PMC's 5.56 load is really just a average .223 load in terms of velocity. True nato spec 5.56 like winchester or federal will do around 3175 fps out of a 16in barrel which is significant considering thats a 300 fps difference.
13.7/14.5 is devastating, controlling in CQB (even with a mini surefire suppressor). Trust me. The longer the barrel, the better. I wouldn't go lower than a 11.5, especially with a full can
I have 7.5 a 12.5 and a 16. I recommend them all for depending whatever you're needing to do. The 7.5 great for suppression or for use in a vehicle. The 12.5 great for suppressed or unsuppressed home defense or mid range hunting. The 16 obviously for ranged scenarios and hunting around 400-500 yards
@@zach3096 Yes, agreed. If I had it to redo over I would have went 18 instead of 16 but I was working with parts for that build that I already had on hand. But yes youre right. On paper there may seem to be a bigger gap and difference, number-wise, between the two, but in terms of real life use does the diff matter all that much? I dont get that nitty gritty on crunching numbers, but I would be willing to bet for most practical applications and uses it wont
Yo! How about doing a part 2 of this video but this time with the average velocities of all those weapons with a silencer/suppressor! That would be awesome and educational 👍
Great comparison test and gear. I'd like to see a test with the 8" and what ammo types still have terminal velocity up to 100yds, soft points, tsx etc.
I'm going to watch so it will help the channel but feel like some of these channels are running out of ideas. There has to be hundreds of vids testing velocity to barrel length.
Slight difference in velocity between 12.4 and 14.5 is due to barrel rifling , the tighter the rifling the more accurate the rifle is but compromising velocity and vice versa
Would be cool if you could test how fast the bullets were going at different ranges to see how fast the velocity drops off. Edit: I guess ballistic calculators would do that for you lol.
The velocity would only drop off at a rate due to air friction which is essentially the same as the BC rating on the ammo exception to this is if you're shooting upwards or downwards so you'll gain or lose velocity due to gravity generally speaking there are bullet calculators that can help you figure out all this stuff even coreolis effect for long shots so velocity out of the barrel is the main thing and not risking accidentally shooting your measurement device if you're not super great Marksmen is a good idea.
I got some from a Springfield Armory Saint 5.5": Perfecta. 223/55g muzzle 1808, 1 yd 1806, 5 yds 1795, 10 yds 1782, 15 yds 1768, 25 yds 1739. Done with a doplar chrono.
12.5” all day. I seen someone else do a similar test on RU-vid that sold me on not going below 12.5” for AR’s. Also the M855 from what I was told is a great pairing for a 12.5” barrel 1/7 twist.
The averages also have the 16” only being a little less than 100’ per second different than the 12.5”, which sounds a little off. Maybe the test on the 12.5” were off. Idk, but this makes me want a 12.5” more than my current 16”
Clint, This has been a really good video and an experiment. I think your thinking about the various speeds is solid, thus giving you lots of new experiments.
To be honest this was mostly as expected, with the exception of the 12.4-14.5 comparison. Also, I never under stood what people were saying about A1/A2 stocks being so audible but this test really demonstrates that fact
When you're shooting an AR with a rifle buffer the sound of the mainspring compressing and extending is very, very noticeable even with heavy passive earmuffs on. I think it has to do with both the larger size of the spring as well as the acoustic properties of the A1/A2 stock compared to any kind of telescoping stock. If you think about it, with a telestock fully extended your face is not right next to the spring anymore for the most part.
Just like a couple of comments, I felt that audibly I could tell the bullets was going to be faster. I know you’ve done some bullpup tests vs long barrel ARs, just wandering how they stack up with this test again.
They are the same barrel lengths. If there would be a difference, it would be because of manufacturing tolerances and procedures. I'm not saying don't do it. Prove me wrong.
The big advantage of a bullpup is a longer barrel for same overall length of rifle. So a bullpup with a 20" barrel might be the same length as an AR with a 12-14" barrel, sometimes even shorter depending on the bullpup
In case anyone was wondering, I calculated the FPS per inch of barrel length for each setup. Starting from the 20" all the way down to the 7.5". 20: 152.6 | 18:166.55 | 16 DI:179.5 | 16:179.06 | 14.5:192.62 | 12.5:223.12 | 11.8:224.06 | 10.3:243.98 | 7.5:291.06.
So 20" for the absolute maximum performance of the 5.56, but "12.5" for the most optimal go-to rifle length. 12.5" sounds pretty attractive to me. Going from 12.5" and on didn't have a huge impact on the velocity. I think 12.5" just might be sweet spot for 5.56.
I have a Centurion hammer forged barrel that has a tapered bore. It's an 11.5 and it will typically have faster velocity because the bore is tapered. A faster twist rate can also cause slightly lower velocity. So if you're testing a 1 to 9 twist versus a 1 to 7 twist, you might get slightly higher velocity out of a 1 to 9. I think with a suppressor 11.5 might be the best, without a suppressor go with the 12.5 for pistols. For my backpack carbine I do have a 10.5 in with a law folder. I would never go below 10.3 for 556 personally
I would LOVE to see this exact test again but going from 55gr to a higher pressure round for each barrel length. Could say oh this 10.3" with a higher pressure bullet is the same as a 14.5" with 55gr.
Exactly why Ronin only shoots 16’s or 12.5’s. I have a 12.5” POF Renegade + that’s prob my fav overall boomstick and barrel length. I have 16’s, 14.5’s, and 11.5’s (in addition to the 12.5) and I no need for anything shorter than the 12.5 (and shortest I’ll run is an 11.5 - that’s just ME, shoot whatever you like, guys... only mentioning that to reaffirm this and other video’s chrono results). My 12.5” POF has a mid length gas system too. A mid length 12.5 is magic.
It’s right in line with what I have observed with many different tests shown on RU-vid. I tend to run the longer barrels in my AR’s, but I don’t mind the increase in weight. Once you carry the M60 in the field, these “heavy” AR’s aren’t a big deal.
That is a test I have been wanting to see for a long time.. I realize it is costly to do such, but, "NUMBERS MAN"... Numbers...... Thank you.. Now, on to the next test, the .50BMG with a 36 inch barrel compared to the 16 inch, 20 inch Barrett.... Annnnnnnd... GO... LOL
Perfect 5.56 AR pistol length is 12.5". Urban rifle length is 13.5-13.7" pinned. Long range 18"-20". Also, in the 12.5 vs 14.5 what are the twist rates? That can affect velocity. Admittedly not as much as there should have been a difference. I think ideally 2" in barrel length should have seen at least a 150fps difference.
The first shot out of your 12.5" barrel was 2,846. That was significantly higher than the other four shots. So either a misread by your chronograph or a particularly hot round. Either way, drop that shot from your calculation and you get an average of 2,774 fps from the 12.5" barrel. Then you have 2,793 fps from your 14" barrel, a slight increase for that extra inch and a half (yeah, I know, that's what she said). So, even dropping that first round really doesn't explain the low numbers from the 14" barrel. It'd be interesting to know if it's the barrel or just something with that particular length of barrel.
I get over 3200 fps with my 20 inch 1/7 twist rifle using xm193 55g ammo. Perhaps your retro 1/12 twist lost you a couple hundred fps. There’s a reason the military stopped using that twist rate.
One thing about that 2200 avg on that 7.5 versus the others is that its the perfect Rifle Caliber Pistol(PCC) and backpack gun. Its also light enough to carry via torso strap. AR9 are goofy. Thx Clint.
I'm sitting good at 10.3 with my DD MK18...I'm in the city so I would only ever need to shoot a couple hundred feet maximum. As long as my velocity is above 2200fps I'm a happy camper 😅
If you use a 20" 1/7 twist barrel then you would be getting the 3100 fps. My FN M-16 clone has the barrel I just mentioned and I'm getting a little over the 3100 fps.
This was really cool. I'm interested in how my 11.5 AR will keep a decent ballistic velocity when reaching out as far as possible. Of course the shorter barrels drop ballistic damage velocities the farther out the target is. I'd love to see that curve between the 7:10 11 12 16 18 20 in barrels all at distance.
What would be a more interesting (and more meaningful) test would be to take a single barrel and test it with the same ammo -10 shots each time then cut it shorter...test again....all the way down to 7.5...start at 18 then 16, 14.5, 12.5, 11.5. Would take a while (days between each test I guess for a smith to re-crown it right each time). Complicated and costly but would get us the REAL info
@@kevinbillow4185 do you know what the article is called? I'd love to read into that as I'm currently in the market for a bolt action but am curious as to which size performs best
With .223/5.56 most new service rifles are 18 - 20 inches as It needs speed. For a compact PDW I would go with an 7.62x39 AK pistol with folding brace & side rail W micro prism and the only 2 you can buy with ease is the Zastava USA M92 with a 10 inch barrel of the full sized 12.2 inch barrel Draco (PM90) both are made in comblock mill factory's, it does not take tome to install picrail for the folding bace but some may need help to rivet on a side optic mount. You don't loose much velocity Vs a full sized AK go with a standard scoop muzzle break so keep it short, can get left or right folding triangle braces , use 30rnd steel mags and good ammo, easy to mount a flashlight with some pic rail on the front handguard and it's a short package that's crazy reliable, even an amature with an optic can hit MOM out to 400 yards, alot of penetration. Sure you could go with a .300blk AR but the size and reliability... AR pistols are kind of picky with short barrels and folding stocks often don't work well so they are never really that compact. But the price if AKs is now insane I'm sure a WASR is well over a grand now so same would be with a Draco, M92 would be more but these are from millitary factory's and have been in use for a very long time it's just the US imports don't have full auto or an underfolding stock. I've had a Romanian 12.2 inch 7.62x39 modded AK pistol with folding brace and optic in my car since I was 21, I have even hunted hogs with it so it's a jack if all and even with the cheapest steelcase ammo and over 2k rounds I have only ever had 1 malfunction (priner was seated too deeply on a Tula cartridge) In the military they issue short barrel 5.56 rifles but they only do that as same mag and same ammo as what everyone else is using but as a civilian Its probably not a good option.
