I can't believe the lack of logic from those who think you'd get better velocity from a 14.5" barrel than a 20" barrel.

@desperado8605

26 күн бұрын

Right and he was using the same rifle for both loads so apple to apple barrel length meant nothing

@coreymoyers

26 күн бұрын

This was not the debate. It was that the higher pressure from the A1 was from faster burning powders that generate more speed in shorter barrels than slower burning M855.

@jacobackley502

26 күн бұрын

@@coreymoyers that too is a common myth. Faster powders don’t have much if any advantage in shorter barrels. Typically the fastest loads out of longer barrels are still the fastest in shorter barrels. The burn rate of the powder only really affects the load density achievable before the pressure ceiling is hit; slower the powder the more you can fill up the case, max velocity per cartridge is typically found with a powder that meets max pressure when ~10% overfilled and compressed

@ostiariusalpha

23 күн бұрын

​@@jacobackley502That is patently false. Faster burning powders reach their peak pressure faster than slower burning powders, meaning they are giving their maximum push on the bullet for longer. The one and *only* reason they slow down the burn rate is to avoid overshooting the maximum allowable pressure of the cartridge and rifle, so as to not blow up the gun.

@ostiariusalpha

23 күн бұрын

​The 6.8x51mm is a perfect example: the hybrid case ammo uses faster burning powder, and hence it has a higher muzzle velocity than the all brass case ammo. Naturally this also means that the MAP is significantly higher also.

Ah, 20 inches of freedom. Just as our lord and Stoner intended.

@G19Jeeper

27 күн бұрын

If our lord intended 20 inches, how come I got 5.

@TroutButter

27 күн бұрын

@@G19Jeeper Short stroke piston?

@greasedog

26 күн бұрын

@@TroutButter Short piston stroke😂

@bobbyberry5559

26 күн бұрын

​@@G19Jeeper 😂

@thomasrandall6367

25 күн бұрын

Yep

When I reviewed at 55F 2,820 was the 14.5" average I got out of 2023 M855A1. The pressure of M855A1 has been dialed back over the years, and some of those reports from early testing, rely on a CONDITIONED temp of M855A1 at 125F..

@blackhawk7r221

22 күн бұрын

In 2020, we were still occasionally breaking bolt lugs with M855A1. Of the multitude of rounds I pulled down, for each 10rd stripper clip I’d see two of the ten loaded to 27.2 gns, another two barely hitting 26.0 gns, and the remaining six somewhere in between. Pretty damn inconsistent over three different DODAC lots.

@BuffRANGE

22 күн бұрын

@@blackhawk7r221 Yep I would say I've seen that inconsistency with powder charge weights on large scale loadings.

Great job answering the critics, I am surprised it was only 190 FPS different for 5.5 inches. I used the A2 in the Marines and I was always sure 20 inches was worth it, looks like 14.5 or 16 is good enough.

@hudsonmeek6728

26 күн бұрын

Muzzle energy is about 1150 ft/lbs for 14.5 and 1320 ft/lbs for the 20. Essentially a 20 inch at 50 yards is equivalent to a 14.5 at point blank. Not a huge difference, but 50 yards of energy shift ain't bad.

@vczs

16 күн бұрын

I believe 855A1 has a faster burning powder which makes it lose less speed in shorter barrels compared to others.

Thank you for doing this clip, it's the perfect video to use when speaking about the m855a1 in either rifle

@Soucka74

23 күн бұрын

Yeah I think it basically shows 8:55 A1 really isn't worth the juice for the squeeze

I once had a short conversation about barrel length in a gun store. I told him what I was looking to buy and mentioned why I wanted a longer barrel. He laughed at me and assured me that barrel length had nothing to do with velocity. I laughed back and asked him if he was serious with me. He smiled and said yes, of course. I imagine he stopped smiling when I abruptly left and never shopped there again.

In 2011 when my battalion made the switch upon our arrival in Afghanistan, the m855A1 was clocked at 2990fps from a standard issue M4A1 carbine. (As per told to us from the big Army) we re-zeroed our AGOGs and got on the birds to our respective fire bases. 3/7 FA 25th ID 2011-2012.

@blackhawk7r221

22 күн бұрын

Yep. We chrono’d the A1’s at never less than 2970 from our M-4’s. Most around 3050 on that hot ass day at Malone 12.

The powder they chose is on the faster end of the burn rate scale. Designed for max velocity out of the 14.5. Thus, the mild increase of velocity from a 20 inch is a side effect.

The 20 inch barrel…. How can you go wrong. Even the weight alone can reduce the recoil for follow up shots. Always gonna love the OG M16A2… plus the chrome lining

You're a sensible guy. I really enjoy your videos. You're very informative and use layman's terms. Keep up the great work, and keep those videos coming!

I believe there have been some tests that do show it inevitably slows down in the barrel, but it was after they reached comical levels of barrel lengths, like 30-40 inches…

Anyone who talks about rifle rounds slowing down because of barrel friction in anything commercially available has no idea what they are talking about. Independently manufactured precision rifles 40-60 inches long still don't have velocity loss. That doesn't mean there isn't friction, friction exists at every barrel length, but it doesn't counter act the increased velocity until close to 60 inches for many rifle rounds.

@nikik5567

27 күн бұрын

Yeah that was nothing but the fanboys making excuses for why their round didn’t perform as magically as they think it does.

@infin1ty850

26 күн бұрын

​@@nikik5567even worse, it's most likely just someone spouting nonsense they heard without any attempt to actually verify it. That's how the majority of this nonsense spreads, just repeating something you just assume to be true.

@Russianmafia10

26 күн бұрын

I didn't think the barrel length was slowing it down, just that maybe the a1 had more acceleration in the first 14.5 inches and at 20 inches the m855 could catch up

@nikik5567

24 күн бұрын

@@1yehny that depends entirely on the load being used.

Of course it was faster out of the 20" barrel. That wasn't the point of the critique. The better comparison would have been to do the m855 and the m855a1 out of a 14.5" in to see if the A1 actually performed better than m855 out of the shorter barrel and verifying the reason for its existence.

@coreymoyers

26 күн бұрын

I do not think he is smart enough to understand or simply one of those guys who hates to be proven wrong.

@chris993361

26 күн бұрын

@@coreymoyers maybe, but I've never gotten the impression that he's dumb. I think he just generally misunderstood or maybe there were some people in the video saying it would slow down in the longer barrel, but when I commented that's not what I said.

@WMDMithbuster

25 күн бұрын

@@chris993361 He is the type of guy who twists things around to always try to prove his point, and his points are ALWAYS counter to the commonly accepted/rational ideas.

@chris993361

25 күн бұрын

@@WMDMithbuster fair enough

@Soucka74

23 күн бұрын

​@@chris9933615.56 mm round was designed around a 20-inch Barrel by Eugene Stoner in the first place, that's what they were spe'd and used. It will gain velocity till about 24", then friction will drag on bullet and slow it down. Of course many factors can deviate this such as, bullet weight, powder type and charge, BC andcseveral other factors. But, in general, you will gain velocity in a longer Barrel all other factors being equal.

Mac im sorry but you STILL did this test wrong. You really should've done green tip and a1 BOTH out of the 14.5, in case the a1 is gaining velocity faster in the first 14.5 inches. Since thats the point of it....

@coreymoyers

26 күн бұрын

He doesn't understand that higher pressure is from faster powders. That is why he still does not get the value of the 6.8x51mm. It is for use in shorter barrels, not overall performance.

@Soucka74

23 күн бұрын

As a general rule you will get more velocity out of a longer Barrel. You should take into account ballistics, powder and bullet used but, in general, the rule stands.​@@coreymoyers

@armstrong2052

23 күн бұрын

​@coreymoyers I'm hoping to get the lwrc 6.8 in a few years, lol

@blackhawk7r221

22 күн бұрын

My unit brought a chrono out to the range one day with our M-4’s and a couple of M-16A2’s. The M855A1’s were about 200fps faster than M855’s. Also, the M855A1’s were about 200fps faster than M855’s out of the 20” M-16A2’s. I don’t know the accuracy of this guy’s meter, but M855A1’s out of our M-4’s was never below 2970fps. 2020 timeframe, back when we were occasionally breaking locking lugs with the hotter A1 ammo.

@Russianmafia10

22 күн бұрын

@@blackhawk7r221 I wonder if they turned down the pressure due to the issues

I think it’s obvious the round continues to accelerate the longer the barrel. I’d be more curious to see if the negligible difference in velocity (M855 and A1) translates down to the 14.5”. ie is the A1 more suited to the shorter barrels as was outlined in your intro to the last video. You start off by saying the A1 is designed to accommodate ballistic performance in M4 length barrels but did all your testing on a mk 12.

From a civilian and KZread enthusiast, I think that higher chamber pressures allow the projectile to accelerate faster, meaning the difference in velocity from a 14,5 vs 20 ‘’ barrel with an Higher pressure round is less than the difference with a “normal” pressure round 🤯

Just because it's a certain length doesn't mean as much as ppl think. The following data is all from LMT MRP barrels. had a 20" that only shot 2700fps - just 100fps faster than 16" with 77gr, which kind of goes against the 50fps per inch meme. I know dudes with 18"s from other brands that are getting faster velocities with the the same ammo. My 11.5 was pretty close if not faster than the 12.5. The 12.5 is only like 60 fps slower than a 14.5. And 14.3 vs 14.5 (both cut from 16") the 14.3 was a bit faster albeit much more broken in... But still, 60 fps higher. Yes I am on the spectrum, yes I'd love to see a video comparing identical barrels. Maybe test them out of the box, then put a few hundred through one and see how that affects velocity compared to the control sample. That was all with 77gr ammo though... One last piece of data was 55gr ruag was doing 3000fps from my 14.3 and 3200 out of the 20". Ted talk complete thanks

How does green tip compare out of a 14.5 barrel? Velocity?

So about 2850 to 2950Fps from the 14.5 and about 3050 to 3150 from 20". The rounds he tests are middle of those numbers. Makes sense. Thats not much different from regular m855. But....the terminal performance is where you find the real change. Although i do wonder if they loaded the rounds to perform better in like...the 10.5 to 11.5" carbines maybe?

Honestly, I’ll take any AR platform, regardless of barrel length. 16in is definitely my preferred barrel length, though. Best of both worlds.

@nikik5567

27 күн бұрын

Eh, I’ll do anything between 11.5 and 20 inches.

@anthonycowart990

26 күн бұрын

@@nikik5567 Same here, I’ve got no real bias, just length preference because I’ve got long arms and a 14.5 or anything shorter feels like I’ve got my arms tied to my chest lol. Im definitely one of the guys you see arm fully extended, thumb over the cover. 😂

I'd be nice if we knew the twist rates of each rifle.

Looks like it's loaded just like m855 now. Guess they had too many problems with the hot version and just didn't tell the troops they changed it.

I would be surprised if the 14.5 inch barrel burns all of the powder, unless a faster powder is used for the load.

A video I wanted to see for ages

My understanding is that the velocity boost from a longer 5.56/.223 barrel ends around 24” or so. After that it DOES actually begin to slightly slow down. But for standard AR-15/M-16/M4 barrel lengths, longer = faster. Since speed is what makes that platform’s ammo most effective, it’s no wonder that its original designer, Eugene Stoner, specified 20” barrels. Free velocity.

I'm not sure they were saying it wouldn't be faster out of a 20 inch barrel. I think they wanted the results of both cartridges out of the barrel lengths they were designed for.

the best thing I saw was m855a1 out of 7in barrel was still about 2200 fps which is amazing

Thanks for the follow up video!!! Beautiful rifles too!

The point wasn't about going faster, it was about the diminishing returns that M855A1 has out of barrels longer than 16 inches. 190 FPS isn't that much of a jump compared to other, older 5.56 loads. Usually thar gap is 300fps or more, going between 14.5 and 20

Shorter barrel. Less rifling and less gas pressure. Longer barrels like 16 inches and 20 inches are always going to hit maximum velocity. Idk why the NFA still exists for SBR’s and suppressors. Soon enough they will be gone

Good job answering the critics

The official standpoint of the army is that the difference between the performance of the two cartridges is so close that you don’t need to re-zero optics

Within reason, you're ALMOST always gonna pick up velocity from a longer barrel

Slowing down in the barrel?😂😂! Love that A2!

hey, I mean no disrespect here, trying to work through a potential viewpoint. I think you should compare standard ammo to the M855A1 in the 14.5" barrel. It may outperform in a shorter barrel compared to the original ammo. I.E., with the original, say itll give you 2800 FPS, with the M855A1 itll give you 2900 FPS The powder may have a short, rapid burn time that excels in shorter barrels compared to other ammo, however in a long barrel, that fast burn time may not give the proper performance as the burn is over before the round has left the barrel. Just speculating here.

You're awesome Mac

Ya this logic is more common than you'd think. I think people think that when the bullet reaches the gas port then 100 percent of the pressure goes into to gas port. It is true that if you compare a 20 inch bolt gun to a 20 inch semi auto then you'd have better velocity in the bolt gun, but the difference isn't as much as some people think.

I'd be interested to see ballistic gel comparison of 10.5" compared to something longer, especially at longer ranges or through armor. I remember seeing a nice accuracy comparison out to 500 yards once, but who knows how much damage it would do.

Regardless of what your Girlfriend or Wife tells Size Matters 😂😂

Everyone knows the longer the barrel the better velocity and accuracy.

20" is still King love it

That makes a difference in spring air rifles. There is an optimum length where you get maximum speed then you loose speed and power because of the power of the air rifle and drag and length of barrel.

Just remember the kids that graduated in the bottom 25% of your HS class are still out there, as grownups, just really dumb ones...

Longer barrel = more velocity, bottom line. However in handgun calibers like 9mm you see diminishing returns after 12" and it starts actually slowing down around 17"

Is the Garmin able to communicate with a Kestel? Was thinking about picking one up.

Let us know what you think about some of the 75 grain and 77 grain offerings out there. Pretty impressive and the way to go with 556 imo.

Who would have guessed giving a overpressure high octane bullet more barrel means it goes more fast

Those people just comment on things they don't know about 😂

There is much more than just the length of the barrel that affects the resulting muzzle velocity. But I don't need to tell you that! 🙂

This shouldnt be surprising to anyone with a basic understanding of ballistics. Longer barrel = longer time for charge to push against bullet increasing its speed. An interesting test would be how long of a barrel do you need for the friction to overcome the push from the powder to start slowing down again. Im sure its been done somewhere

The 3.5 inch difference isn't reallistically going to matter all that much velocity wise.

When armor is this available and cheap. 20" barrels make alot of sense

MAC, the suggestion is no that the new ammo's bullets slow down in longer barrels, but that the advantage of the new high pressure ammo might show more with short barrels. You results suggest the new ammo is just like the old ammo, or slower, regardless of barrel length. Hype over substance.

The only time barrel length is going to slow a bullet is when it is super super super long and you literally burn all the powder before it leaves the barrel and then you can get a slowing effect but you need like a 4‘ or 5‘ barrel for that to start to happen

Thats still good velocity for a 62gr round out of a 14.5

when a bullet hit the gel at too much a speed, it may decrease the penetrate distance in the gel, i remember the m855a1 immediately shatters upon entry and receive a worse penetration distance than m855 which has a lower speed, i believe this is what they meant when they want you to try 14.5', are there actually people saying 5.56 gets slowed down in a barrel length it was originally designed for?

Who woulda thought 😂😂

Why do people think physics fails to apply in some situations?

Is it a Mid-Length gas system in the 14.5? Just wondering in general

Where do you get the M855A1 I’m interested in getting some and switching from tip

The 5.56 was designed for a 20" barrel.

what about some m995 testing? or a m995a1(i just made it up and what i mean is high pressure tangestan core and a designe like m855a1 instead of steel)

As Paul said before, does that make a difference? Also only 2 rounds doesn’t show the standard variation velocity between rounds.

I get so tired of guys bragging about their 7” ARs when they don’t understand how velocity dependent the 5.56 is. You’re getting great performance out of a 20” bbl vs 10.5, 11.5, etc.

@BuffRANGE

26 күн бұрын

A1 works even from a 7.5” barrel but no doubt 16-20” is where it shines.

@HDBujutsu1775

26 күн бұрын

@@BuffRANGE 7.5 bbl 5.56 is a joke and a waste…🤦🏻

@BuffRANGE

26 күн бұрын

@@HDBujutsu1775 no disagreement. I only use it for testing but for me it gives us 5.56 rounds terminal effect at range. A1 is still fragmenting at 2,200 fps :)

Lmao 😅 slower down in 20in barrel that's riot . Good Stuff 😅

Did people forget that 5.56 was designed -for- a 20in barrel?

That's about correct

In 2024 who would doubt this well established team information ? All the “new” shooters have moved from California, and New York to the South ?

Are both guns the same twist?

What sight is that on the M4?

So yes a longer barrel does make a difference by 200 fps. That caliber is under powered though. Gave my upper away. Now I use 300 blackout with 10” upper cow. My other two are 6 ARC One with 16” the other with 18” upper. Energy and distance. No more poodle shooters for me

Now what is it out of a 10.5 or 11.5?

What’s the twist rate on each?

The colt is technically a a3 because you can take off the carry handle

Fuckin i swear😂 24” at 1/8 twist is peak 5.56/.223 performances

How does one aquire 55a1 dude ive been looking since 2018

What I do not like in service, is that I have to use what idiots give to me. I don't like the concept of the do it all fighting rifles. Many good guys died with 22 noise makers with lots of 'light weight ammo' for suppresive fire. Starting in Vietnam. Going back to the old 308 had been cheaper this time. But 270 is made by the same stupid spirit of the older days. A short barrel fighting rifle for room clearing and the sniper. Sounds great. They will never offer the high pressure loding. They tell you for 'accuracy'. That means it burns down barrels very fast. Even more so with fast burning powder. On full auto you will fu..ck up your barrel in one day. Better balistics of the round won't make up for this on long range. Close up a 308 still hits harder. The problem is that combat is all about distance. In legion we went hiking with 80 pounds and we didn't know recoil. You can't beat a worrier. I will defend my constitution and freedom with an AR 10 12 gauge that uses pistol powders. Up to 50 yards buck pissed angry into faces and body armors won't be a thing. It works for birdhunting drones and as a door opener as well. With the magnifier and slugs it takes care well over a hundred yards. Up close a knife and a 357 snub. After making some space there is a cheap light weight 300 mag bolt with a good scope on my back. With the wind in your a..ss or your face you only have to know your drop. I will be too far out of distance for a 270. I think that's why the US looses so many good men in countries they have no buisiness being in. If you will face real war for the first time, you will learn not each single wounded man will be extracted by the space shuttle.

Did people really say the longer barrel slowed it down? Man there are some dumb people! Ammo manufacturers use 24 inch barrels as a baseline for their testing and rate estimates!

Personally, I like a 16” best

Love my A2 clone the 20 inch shoots smoother i think

M16 one of the most sexiest and ergonomically perfect rifle to shoot far and straight ffs

Who tf thought the short barrel would be faster fps? Lol

190 dang.

A barrel would have to be ridiculously long to slow down a bullet. That'd be an interesting video.

@502outlaw2

23 күн бұрын

If I remember correctly, the 5.56 starts slowing down in the 24 inch barrel.

That logic is why bARfcom became a cesspool in the early 2000’s. Everyone is an expert and yet they know nothing.

The M855A1 is loaded with the 14.5 barrels in mind, so it makes sense the powder wouldn't gain much from extra length. Side note, how are you and other KZreadrs even getting M855A1?

24 inch barrel for my 6.5 Creedmoor

So from 14.5 inches out to 20 inches the bullet is still accelerating ⁉️👍⁉️🇺🇲⁉️

It's a necked down cartridge and they think it would have burnt all the powder in a 14.5? There's a lot of stupid people in your comments if they really think that. Longer barrel, even up to 24", will give higher velocities.

Well of course it is, anyone who shoots knows (or should know) that the longer the barrel the better the FPS. If you don't know this who need to take some basic science classes. When you buy a box of ammo is list the FPS on it but it doesn't mean your going get it if your running short barrel.

its almost as if a long barrel gets more velocity.

Why do 20” inch barrels feel like they shoot smoother somehow?

@DocMitchell69

26 күн бұрын

It’s the rifle length gas system. It allows the gas enough time to dissipate and translates to a smooth recoil impulse. If I didn’t have a shoulder injury I’d like a 20 inch rifle again.

Why do you listen to people who have no idea what they are talking about. It would probably have to be a 30" barrel for 5.56 to start slowing in the barrel.

Yes

We said the difference would be more significant from a shorter barrel. You need to compare the M855 vs the M855A1 out of a shorter barrel to see the advantage of the higher pressure A1 offers. The more videos I watch of yours, the more I realize you struggle to visualize what is happening with higher chamber pressures. For example, the recent Sig event confirmed what I told you about the 6.8x51mm. The higher pressure is not for additional performance. It is so you can achieve similar performance from a shorter barrel. You are definitely better on camera than I ever could be, but I am a bigger ballistics nerd. I am confident I could help you understand if you could swallow your pride.

This is surprising how ?

People were really saying that in the comments for other video? Now I have to go watch it. 😂

Feels good to prove them wrong, keyboard commandos.

Wow it's not subsonic ammunition that was being used! The lack of understanding of external ballistics is baffling

Of course a 20" barrel is faster even if not drastically so. You'd need a slower bullet and like a 30" barrel or something crazy for it to be completely burned before exiting the barrel and starting to slow down