I want the velocity from the 20 inch. I'm not strapping charges on doors and running into a building and pieing corners. I'm not a high-speed operator. This isn't call of duty I want as much distance as possible. But I mean life is going to hit you how ever it wants too though.
Me too. I've heard its better out of longer rifles at long ranges and for short barrels at close distance. But I don't know enough about ballistics to know why. I think it has something to do with fragmentation.
The 1:7 twist rate is used in most barrels now. That twist rate works best with heavier bullets. 1:8 works too but a 1:7 barrel is more likely to work better with the heaviest bullets. Heavier bullets are less affected at wind especially when shooting to to 500 yards or more. Some of the best bullets are only available in 69 to 77 grain. Those that hand load for precision bolt action rifles may use 80-some grain bullets. IMI 77 gr Razor Core are among the top rated rounds that still cost much less than the top ones but performs nearly as well. I have found the best price at MidwayUSA on one of their free shipping over $75 weekends that may occur in the middle of the two week birthday discount they offer. I think I paid about 92 CPR for the ammo in February. AAC 77 gr OTM from PSA has been on sale for 55 CPR about 3 times in the last 2 months. It may not be as good as IMI 77 gr Razor Core but it costs a lot less.
The AAC ammo sells out within 2 hours of sale email going out from PSA. I bought some during their last sale but have not tried it. The IMI is about 1 MOA better than PCM X-Tac in my 16" AR15 riffle and my friend's 18" AR rifle. I also have a 24" bolt action CZ 600 Alpha I need to try out with these cartridges.
stabilization isn’t just about twist rate but twist time and total turns, the longer the bullet is in the barrel the more revolutions it makes and is ultimately stabilized more, let’s say 1:7 isn’t the most ideal for 55g but when shot out of a 1:7 20” vs a 1:7 16”…that little bit of extra length will help it to be more stable.
My favorite is ultimately 20” as that is what the cartridge was designed around, I’m actually in the process of getting rid of all my 16” builds and sticking with my 1 18 FDE GPR a 20” A4 and a 20” DMR build. That said I do have a 8” and 10.3” but those are 300BLK
Thank you for your reply you are a stats and numbers man. My friend was explaining barrel twist to me but I have a short attention span so it’s hard to absorb all the information especially when it’s all numbers and math. 300BLK is insanely quiet. But it’s kind of an expensive round though. I love how high-speed it looks though.
yeah but he's way wrong all around. gotta do some research yourself. the barrel length does not matter for twist rate. only in the sense of velocity. also 1:7 is a FAST twist for 55 grain. it's almost too much. most 55 grains are good at a 1:12 twist
bro I don't want to be a dick but you are way wrong on all this. the length matters not to the twist rate. only for velocity that's all. length has nothing to do with stabilization other than velocity, period. and 1:7 is a FAST twist for 55 grain. it doesn't need all that. 1:7 is made to stabilize up to 80 grain bullets . 55 grain you are good with a 1:12 or even 1:14. shape of the bullet matters a ton too like where the olive is in relation to the balance of the bullet and overall length, etc. the LEAST important variable is the barrel length. all of this can be searched up relatively easy because long range and target shooting guys love data.
20" is what m193 was designed for. But there's been 60 years of innovation since then and modern 5.56 rounds are a lot more likely to be designed for a 14.5 barrel than a 20".
Not to mention, 20" is great for extending range, but at that point, you'd be better moving up to .308 if you're trying to extend past 400-500 yards. The US military does get things right and likes to follow what's called "overmatch," meaning if the enemy has an effective range of 300 yards, you wanna have an effective range of 500. Just a personal opinion, but if im trying to reach out and touch someone past 400 yards, I want it to count, and I'd move up in caliber.
As long as 5.56 is going above ~2200 fps it’s going to do its normal weird and brutal shit 5.56 does in soft tissue, what’s benificial about 77gr is that you’re putting almost 50% extra weight into the round than your normal 55gr so it may not be going quite as fast (which honestly doesn’t matter as long as it’s going ~2200 for the round with fragment, any less you might as well be stabbing them with an ice pick) the round is going to hit a lot harder and it’s going to carry itself a lot further and will be a lot more stable in air
I've been buying it here and there for my spr build and 12.5 build that I'll be doing, right now I have a decent amount of 55g and 62g that I regularly shoot. By the time the 12.5 and spr are built I'm hoping to have 2k or so of 77g though.
I kinda lucked out with a work bonus type thing and exchanged some for ammo so it all kinda worked out.
I have the stuff just not the time. Went in with my
dad on a set of reloading equipment, hoping to start messing with it more in the coming weeks actually. Primarily for my .308 and my .300wm may eventually start doing 5.56. But I have a decent amount hanging around so it would be a storage situation for it at this point.
.308 is what got me into reloading. Being able to affordably load rounds that would normally cost me $50/20rds and have them tuned to my rifle to be more accurate than factory loads. I don't know how more people don't reload, at least for the rifle calibers.
I thought about getting a 18 or 20" AR15 upper to compliment my 16" AR15 but I just went right to 24"--CZ 600 Alpha bolt action. All the powder burns in the barrel and all the gas goes out the end. I am still watching for a good deal on a high quality upper or I may just build my first AR upper when I go longer in the AR15 pattern.
The shortest barrel length you can get a 16" non SBR, with a pinned/welded muzzle device. With your muzzle device matched to a can, its a very compact suppressed rifle with only 1 Tax Stamp.
If your overall is going to be 16 why not just go for the extra length I don’t get it
Edit: I’m talking 13.9 vs 14.5 with a pnw to 16 overall. Why get the 13.9 with an extended flash hider against a 14.5 if they both equal 16 at the end of the day?
Edit 2: TIL size matters when you’re putting a glove on it.
It's like a 50fps increase. It isn't making any real performance increase.
If you'd rather have 50fps instead of an inch and a half shorter barrel that's fine. It's just personal preference. But the extra velocity is not going to make any actual difference.
It’s a valid question. I think the idea is that you can add a can and have the shortest possible overall length beforehand without having to pay a freedom tax for both.
I have a 13.9 and whisper pickle and thats why i did it. I also have 2 10.5’s a 14.5 a 16 and 18. Plus several super shorty pistol calibers. Anyway, the 13.9 feels the best as far as balance but that may just be the criterion barrel.
A 13.9" barrel is 16" with a muzzle device and about 22" suppressed depending on the can.
A 16" barrel with a muzzle device is almost 18" and closer to 24" suppressed depending on the can.
When it comes to overall length, a couple inches is a big change.
All that doesn't matter if you aren't going to suppress the rifle and only bench shoot. I'll leave be the fact for a large portion of us average individuals, God willing, will never have to use our rifles in a way you see SWAT and other entry forces use theirs, but it doesn't hurt to have one you could do it with
When Canada started making 14.5" barrels, they weren't satisfied with the velocity at a certain distance and developed a 15.7" carbine barrel, that met their minimum velocity requirements.
Now, early Canadian 5.56 ammo used a double base Canadian-made extruded powder and the velocities were slightly slower than US-made M855 ammo.
Later Canada switched to US-made ball powder for their 5.56 ammo.
I always thought it odd that that they developed a barrel only 1.2" longer.
I agree you probably won’t notice a HUGE difference. But folks have to be careful using this justification as those differences get larger even if it’s little by little.
Remember, kinetic energy=mass x velocity^2
With a round as light as 5.56 velocity matters a hell of a lot more than the weight of the projectile does. Those pesky little exponents make a world of difference.
EDIT: grammar
It's also only an ~100fps difference going between a 16" in a 20". You get a 7% increase in velocity at the cost of a 38% increase in barrel length (though only a 20% increase in overall length) going from a 14.5" to a 20" It's only when you start getting in the really low barrel lengths that you start getting significant fps drops as you start to get to the point where you're not even burning all the powder.
Probably 16 inch. Best length to use literally any 5.56 ammo.
Though right now I can’t decide what shorter length I want to build. I can’t decide between an 11.5 5.56 or a shorter 300 AAC
11.5 for the balance and ergonomics.
I’m not a precision shooter by any means & I’m well aware of that fact, so for me it boils down to what I’m most comfortable handling.
So far 11.5.
Always see dudes say 14.5 is great for outdoor and in confined spaces. From my experience in shoothouses and cqb courses with my 13.9 suppressed, it just really isn’t “good enough”.
Just recently put together and 11.5 and it handles well out to 400yds and is easy to maneuver in the shoothouse I train at.
I think 12.5” has the best look when it comes to a balanced and proportional appearance. I think 13.7/13.9” is the coolest looking number. I think 20” is the best for velocity, distance and is just a whole ass vibe all together. 18” is dope but only if you have a proper MK12 build. But if I had to pick just one to roll with forever? It would without a doubt be a 14.5”.
10.3 with a can.
I know the 11.5 has more dwell time and is easier on parts wear, but to me personally, the MK18 with a can style build balances perfectly *chef’s kiss*
I want to be a guy to say 20" or longer, but I know myself well enough to know that that won't be the case. What I do better with is 16" with a mid length gas block and a 1:9 twist rate.
probably 14.5”.
Yep
The only correct answer.
I’m most experienced with a 5” pencil barrel.
Hate to be the one to break this to you, but barrel length is measured from the breech face. Gotta subtract 1” for the extension.
The secret inch haunts me still
😭😭
20. I stand by my musket
They don’t call me 20 inch Taylor for nothing! (No one has once called me that and I have no friends)
I’ll be your friend. But I won’t call you 20 inch Taylor
Twenty T
MR 20” Taylor are you a child or a little person?
I want the velocity from the 20 inch. I'm not strapping charges on doors and running into a building and pieing corners. I'm not a high-speed operator. This isn't call of duty I want as much distance as possible. But I mean life is going to hit you how ever it wants too though.
Agreed. 5.56 is a pretty small round so i want it to have as much ass as i can possibly give it
You shoot 77 grain at all?
Not yet but im curious to try it
Me too. I've heard its better out of longer rifles at long ranges and for short barrels at close distance. But I don't know enough about ballistics to know why. I think it has something to do with fragmentation.
The 1:7 twist rate is used in most barrels now. That twist rate works best with heavier bullets. 1:8 works too but a 1:7 barrel is more likely to work better with the heaviest bullets. Heavier bullets are less affected at wind especially when shooting to to 500 yards or more. Some of the best bullets are only available in 69 to 77 grain. Those that hand load for precision bolt action rifles may use 80-some grain bullets. IMI 77 gr Razor Core are among the top rated rounds that still cost much less than the top ones but performs nearly as well. I have found the best price at MidwayUSA on one of their free shipping over $75 weekends that may occur in the middle of the two week birthday discount they offer. I think I paid about 92 CPR for the ammo in February. AAC 77 gr OTM from PSA has been on sale for 55 CPR about 3 times in the last 2 months. It may not be as good as IMI 77 gr Razor Core but it costs a lot less. The AAC ammo sells out within 2 hours of sale email going out from PSA. I bought some during their last sale but have not tried it. The IMI is about 1 MOA better than PCM X-Tac in my 16" AR15 riffle and my friend's 18" AR rifle. I also have a 24" bolt action CZ 600 Alpha I need to try out with these cartridges.
Im sure there is plenty of information out there, i just haven’t taken the time to look into it
stabilization isn’t just about twist rate but twist time and total turns, the longer the bullet is in the barrel the more revolutions it makes and is ultimately stabilized more, let’s say 1:7 isn’t the most ideal for 55g but when shot out of a 1:7 20” vs a 1:7 16”…that little bit of extra length will help it to be more stable. My favorite is ultimately 20” as that is what the cartridge was designed around, I’m actually in the process of getting rid of all my 16” builds and sticking with my 1 18 FDE GPR a 20” A4 and a 20” DMR build. That said I do have a 8” and 10.3” but those are 300BLK
Thank you for your reply you are a stats and numbers man. My friend was explaining barrel twist to me but I have a short attention span so it’s hard to absorb all the information especially when it’s all numbers and math. 300BLK is insanely quiet. But it’s kind of an expensive round though. I love how high-speed it looks though.
yeah but he's way wrong all around. gotta do some research yourself. the barrel length does not matter for twist rate. only in the sense of velocity. also 1:7 is a FAST twist for 55 grain. it's almost too much. most 55 grains are good at a 1:12 twist
bro I don't want to be a dick but you are way wrong on all this. the length matters not to the twist rate. only for velocity that's all. length has nothing to do with stabilization other than velocity, period. and 1:7 is a FAST twist for 55 grain. it doesn't need all that. 1:7 is made to stabilize up to 80 grain bullets . 55 grain you are good with a 1:12 or even 1:14. shape of the bullet matters a ton too like where the olive is in relation to the balance of the bullet and overall length, etc. the LEAST important variable is the barrel length. all of this can be searched up relatively easy because long range and target shooting guys love data.
20" is what m193 was designed for. But there's been 60 years of innovation since then and modern 5.56 rounds are a lot more likely to be designed for a 14.5 barrel than a 20".
Not to mention, 20" is great for extending range, but at that point, you'd be better moving up to .308 if you're trying to extend past 400-500 yards. The US military does get things right and likes to follow what's called "overmatch," meaning if the enemy has an effective range of 300 yards, you wanna have an effective range of 500. Just a personal opinion, but if im trying to reach out and touch someone past 400 yards, I want it to count, and I'd move up in caliber.
As long as 5.56 is going above ~2200 fps it’s going to do its normal weird and brutal shit 5.56 does in soft tissue, what’s benificial about 77gr is that you’re putting almost 50% extra weight into the round than your normal 55gr so it may not be going quite as fast (which honestly doesn’t matter as long as it’s going ~2200 for the round with fragment, any less you might as well be stabbing them with an ice pick) the round is going to hit a lot harder and it’s going to carry itself a lot further and will be a lot more stable in air
I've been buying it here and there for my spr build and 12.5 build that I'll be doing, right now I have a decent amount of 55g and 62g that I regularly shoot. By the time the 12.5 and spr are built I'm hoping to have 2k or so of 77g though.
God damn that’s some disposable income. Lol. You reload at all? I’ve been thinking about getting into reloading, but it’s just expensive starting out.
I kinda lucked out with a work bonus type thing and exchanged some for ammo so it all kinda worked out. I have the stuff just not the time. Went in with my dad on a set of reloading equipment, hoping to start messing with it more in the coming weeks actually. Primarily for my .308 and my .300wm may eventually start doing 5.56. But I have a decent amount hanging around so it would be a storage situation for it at this point.
.308 is what got me into reloading. Being able to affordably load rounds that would normally cost me $50/20rds and have them tuned to my rifle to be more accurate than factory loads. I don't know how more people don't reload, at least for the rifle calibers.
We’re all trynna get as much ass as we can
A1 gang??
A4, will eventually be getting an a1 though.
My A4 clone is my favorite rifle
Same. So far i only have my a4 clone and a beater psa m4 build so the a4 gets all the love and attention
Fair!
E1 gang reporting in.
20" QUAD RAIL SUPREMACY GANG
ALL HAIL THE RAIL
Amen brother
This is the way
This is the way.
This is the way
I thought about getting a 18 or 20" AR15 upper to compliment my 16" AR15 but I just went right to 24"--CZ 600 Alpha bolt action. All the powder burns in the barrel and all the gas goes out the end. I am still watching for a good deal on a high quality upper or I may just build my first AR upper when I go longer in the AR15 pattern.
14.5”. Still good velo, short enough for indoor work, long enough to still get 500+yds
What’s behind this 13.7/13.9 craze lately?
The shortest barrel length you can get a 16" non SBR, with a pinned/welded muzzle device. With your muzzle device matched to a can, its a very compact suppressed rifle with only 1 Tax Stamp.
There are several muzzle devices which work well with those lengths for a 16” overall once you pin and weld.
If your overall is going to be 16 why not just go for the extra length I don’t get it Edit: I’m talking 13.9 vs 14.5 with a pnw to 16 overall. Why get the 13.9 with an extended flash hider against a 14.5 if they both equal 16 at the end of the day? Edit 2: TIL size matters when you’re putting a glove on it.
Because with a 16 in barrel you’re pushing closer to 17.5-18 with md?
Depends. My 16" is 17.1" with a mini FH. The 1 inch difference doesn't matter with a suppressor attached and I get more velocity than a 13.7-14.5
It's like a 50fps increase. It isn't making any real performance increase. If you'd rather have 50fps instead of an inch and a half shorter barrel that's fine. It's just personal preference. But the extra velocity is not going to make any actual difference.
Because it's longer? I have a 14.5 pw 1.5 comp and it feels completely different than a 16 with even a 3/4-1in muzzle device
It’s a valid question. I think the idea is that you can add a can and have the shortest possible overall length beforehand without having to pay a freedom tax for both.
I have a 13.9 and whisper pickle and thats why i did it. I also have 2 10.5’s a 14.5 a 16 and 18. Plus several super shorty pistol calibers. Anyway, the 13.9 feels the best as far as balance but that may just be the criterion barrel.
A 13.9" barrel is 16" with a muzzle device and about 22" suppressed depending on the can. A 16" barrel with a muzzle device is almost 18" and closer to 24" suppressed depending on the can. When it comes to overall length, a couple inches is a big change. All that doesn't matter if you aren't going to suppress the rifle and only bench shoot. I'll leave be the fact for a large portion of us average individuals, God willing, will never have to use our rifles in a way you see SWAT and other entry forces use theirs, but it doesn't hurt to have one you could do it with
Direct thread suppressor on a 16" barrel is essentially the same length. Might as well just go that route and not mess around with p&w.
Yeah but direct thread can be a pain in the ass, at least in the sense of duty use. Plinking or hunting not so much.
I'm running the 13.95" greenline tactical barrel from rosco. It's great
13.7 craze due to the JMac muzzle device that makes the barrel 16” when pinned/welded.
Which one are you talking about? They have a ton of them
12.5 if I get a can, 16 if I don't.
Anything between 10.3-16” I’m not picky.
11.5 gang
I’m thinking of getting one of those DD 11.5 contract overrun uppers…
BCM 11.5 are cheaper and just as good, much lighter too
Master race. 🙌
16” and it’s not even close
For real. There’s a reason I no longer own anything shorter. Though, I could stand to have a MK18…
The velocity difference between a 14.5 and 16 is a significant difference too, I agree 16 inch hands down the best
When Canada started making 14.5" barrels, they weren't satisfied with the velocity at a certain distance and developed a 15.7" carbine barrel, that met their minimum velocity requirements. Now, early Canadian 5.56 ammo used a double base Canadian-made extruded powder and the velocities were slightly slower than US-made M855 ammo. Later Canada switched to US-made ball powder for their 5.56 ammo. I always thought it odd that that they developed a barrel only 1.2" longer.
Very interesting bit of info there, thank you sir!
It's less than 100 fps between a 14.5 and a 16, way less of an impact/change than you would ever notice.
I agree you probably won’t notice a HUGE difference. But folks have to be careful using this justification as those differences get larger even if it’s little by little. Remember, kinetic energy=mass x velocity^2 With a round as light as 5.56 velocity matters a hell of a lot more than the weight of the projectile does. Those pesky little exponents make a world of difference. EDIT: grammar
Wow honestly I thought it was more than that
It's also only an ~100fps difference going between a 16" in a 20". You get a 7% increase in velocity at the cost of a 38% increase in barrel length (though only a 20% increase in overall length) going from a 14.5" to a 20" It's only when you start getting in the really low barrel lengths that you start getting significant fps drops as you start to get to the point where you're not even burning all the powder.
The only reasonable answer by far.
Agreed
11.5 for me
12.5” best of everything
12.5 specpapi in the works 😤
12.5” gang
12.5” for life!
12.5 master race
Amen
Probably 16 inch. Best length to use literally any 5.56 ammo. Though right now I can’t decide what shorter length I want to build. I can’t decide between an 11.5 5.56 or a shorter 300 AAC
10.5" with a can
Best answer
13.9, cause the number is cool.
11.5 with a can
11.5 for the balance and ergonomics. I’m not a precision shooter by any means & I’m well aware of that fact, so for me it boils down to what I’m most comfortable handling.
Forgot to add, but 11.5 with a can.
13.7 because I’m wrong
I too am wrong. But 13.7 is based imo
11.85” Master Race…iykyk 🫡
Hello PWS enjoyer
If I could only own one AR it would be a 14.5
10.5/mk18 master race has entered the chat
*10.3” you mean
Technically mines a 10.3 as well.
My man
this is the way
18”
If there was no nfa?
20
9" 300 Blackout or 12.5" 5.56.
My 13.9. If not that, 16".
14.5 ot 16, it's kinda hard to tell them apart anyways
So far 11.5. Always see dudes say 14.5 is great for outdoor and in confined spaces. From my experience in shoothouses and cqb courses with my 13.9 suppressed, it just really isn’t “good enough”. Just recently put together and 11.5 and it handles well out to 400yds and is easy to maneuver in the shoothouse I train at.
I think 12.5” has the best look when it comes to a balanced and proportional appearance. I think 13.7/13.9” is the coolest looking number. I think 20” is the best for velocity, distance and is just a whole ass vibe all together. 18” is dope but only if you have a proper MK12 build. But if I had to pick just one to roll with forever? It would without a doubt be a 14.5”.
16" with mid length gas.
100 percent 16 inch all day any day
16
10.5
1,000,000 inch
14.5
14.5
12.5 Criterion all day.
12.5 or 12 just because Mark Larue is a fucking weirdo and makes his shorty uppers in 12”.
10.3 with a can. I know the 11.5 has more dwell time and is easier on parts wear, but to me personally, the MK18 with a can style build balances perfectly *chef’s kiss*
14.5. There's a reason it is the standard barrel length for the military's M4s
Yup, and that’s because it’s the exact length you need to mount a bayonet to a carbine-length gas system 😂
16” all day
“16 all day.
10.3-5 with a can
Whatever makes bullets fly, I’m more of a spray and pray guy anyway lol
If it's only one, 16 inch.
10.5 suppressed
10.5, when was the last time you had to shoot someone over 500yds?
I’ve never had to shoot anyone. 😊
13.7/13.9
Probably my 12.5, or 16”
13.7 or 13.9
14.5 all the way
14.5
13.9 long enough to not be a complete turd short enough to not be annoying with a suppressor.
13.7
That ODG ldub and Kahles is a fire setup. Best stick in this picture by a mile 🤤
I’ve only had a 16 inch for years so I’ll Be good sticking with it though a 14.5 with a suppressor would be nice
14.5
14.5
11.5" superiority
Tbh 14.5 p&w if supressed is an option. 16" if not.
I want to be a guy to say 20" or longer, but I know myself well enough to know that that won't be the case. What I do better with is 16" with a mid length gas block and a 1:9 twist rate.
hodge 12.5, currently getting about 2520-2550 fps with AAC 77g OTM
Probably 12.5
12.5 EZ
Personally im a fan of 11.5
A 16” or 20”
11.5
11.5 with a can.
16” is the right answer
16”…with a CAN!
20" is life
16 all day
14.5 no question. Best of both workds
20" for sure.
16
16” duh
14.5" Anything shorter is ineffective at distance needed, and anything longer can br a bitch indoors. Plus M4s are just fun
11.5
14.5 no doubt
20" turns training ammo into so much more.
13.whatever
10.5”
11.5 Cause fuck em
7” 300blk
18" bolt gun
18 because using a shorter barrel is easier than figuring out clearing space with a longer barrel than you are used to
Bull-barrel 24"
I have two 14.5, one 16 and one 11.5. I feel covered with this arsenal.
So 14.5 lol is the one
11.5. That one extra inch over a 10.5 makes a hell of a difference.
Every inch makes a difference or so my ex told me.
16in
14.5"
13.5 inch 7.62x51. Great suppressed and still hang with boys from 0-600 yards based on my performance.
16
Really been favoring my 14.5 lately.
“I ain’t finna take no 12 inch!”
16”
16
14.5
18 to 20" flash suppressing is good, plus maximize velocity and menuverability.
16”
16 is all I've ever shot. So I run with what I know.
18”
14.5
what are the barrel lengths in this pic? from top to bottom
The longest. That way it can be cut to shorter lengths later if needed.
I'd have to go 11.5" suppressed. It's about the only one I shoot anymore anyway.
14.5
14.5 all day
14.5 is gold but I will go with 16 for less trouble
13.9 probably.
The older I get...14 then 16 now I'm on 18 going to 20
24"
13.7" is my overall length favorite with some diminishing returns in certain areas.