What does Jow Forums prefer and why?

I was PSA would do 18" midlength but they're all 18" rifle

How do you make sure scope has zero cant?

>How do you make sure scope has zero cant?
I used a mini-level I got from Menards or something.

thats what you get with Poverty State Armory

Just build your own, its not hard and you get exactly what you want. If you are concerned about headspacing you can get a barrel with matched bolt from Faxon.

Rifle length, since there is NO reason to use anything else, in an honest, practical sense.

Is 20 inch best if I want to shoot cheap low grain ammo?

when shopping for my last build, i wanted a high end barrel and since it was going to cost a good chunk of change, i did a lot research and comparisons of specs, online videos, anecdotes from people with personal experience, etc. and from what i gather, if going with a 16" barrel, the midlength gas system has a better record of reliability in terms of FTE's, bolt cycling, and less felt recoil, all including sonic, subsonic and suppressed rounds of varying weights and velocities

14.5 middy mustardrace coming through.

Attached: WP_20180519_008[1].jpg (3072x1728, 3.11M)

>2018

>Still looking at antiquated shit like fixed front sights, non-free float handguards, 16 inch barrels with carbine gas systems, and heavy profile barrels

The industry has almost standardized on mid length gas systems. Unless you go below 14.5 there is zero reason to use a carbine gas system

The best barrel length for a AR carbine is 14.5 pinned, lightweight or pencil profile, mid-length gas system, low profile gas block, and a modular (M-LOK) free float hand guard.

ay hol up. is that a real third pin?

>Jow Forums owns guns
gtfo newfag

That's a rain drop silly.

Attached: WP_20171007_003[3].jpg (3072x1728, 2.53M)

i dont know msd, i can see it both ways.

10.3 SBR because the barrel was on sale.

Serious question, why would you want a dissipator? What advantage does it have over every other gas system?

WHat scope is that

>11.5"
s o y

>Let's build a rifle that relies entirely on muzzle velocity to be effective, then shorten it so you can't get high muzzle velocities.

20" unless you're retarded.

Dissy's purpose was to have rifle-length sight radius with a carbine length barrel. Only really matters if you're using irons.

Vietnam LARPfags, when will you learn

100-200 FPS is not an appreciable difference. Only 55 grain ammo relies on fragmentation for wounding effects. The loss of fragmentation range from a 20 inch barrel to a 14.5 is less than 50 yards. 14.5 M4 rifles still has a rough fragmentation range of 150 yards. Look at some data but most firefights happen within this distance. For civilians its much closer than that.

All of this is made irrelevant with the shift to 75 and 77 grain 5.56 ammo, which does not depend on fragmentation for its wounding effects.

I see no purpose for a 20 inch barrel on anything but a niche precision or hunting AR build

>m193 and m855 are the only two 5.56 loads in existence and there has been no improvement since then

A longer barrel will increase the round's velocity. Since 5.56 depends on velocity to fragment and increase wounding potential, then a long barrel will make 5.56 deadlier than if it is too slow to fragment. A 1:9 twist or 1:12 twist barrel will adequately stabilize 55gr bullets.
If you want, you can get a 1:8 or 1:7 twist barrel to shoot heavier (up to 77gr) bullets, which may be optimized for shorter barrel lengths.

If you want your gun to accurately poke holes in paper at up to 400 yards, then a 20", 1:9 twist barrel is great. If you want to meme up with an sbr or some other shit, then you can do that, too, but it will be more expensive overall.

>5.56 depends on velocity to fragment and increase wounding potential

not him, but how exactly does that work? I always hear about how 5.56 fragments but I never learned about *how* exactly it achieves that effect.

anything but 20" is shit, not to mention not maximum aesthetic.

one thing to note is basically any elite group you can name (delta, rangers, seals etc.) uses SBRs in some capacity if not primarily whereas basically none of them use 20" ARs anymore.

Attached: EOjfSDiPfH1QVO8dY8Ce-jRycAjcbG1yvgIo1i3QDvk.jpg (1024x734, 149K)

>I see no purpose for a 20 inch barrel on anything but a niche precision or hunting AR build
I like the cut-your-chamber-pressure-in-half thing. I also like the almost total lack of any recoil impulse. I think an extra several inches is a small price to pay for these things. And a 20" barreled AR is still slim and trim next to almost any hunting rifle.

10.5

10.3", 14.5" mid length, and 18" rifle length

20 inch rifle length. even in a vehicle I never saw the issue with the extra few inches.

>I always hear about how 5.56 fragments but I never learned about *how* exactly it achieves that effect.
At greater than 2600fps, the small bullet breaks apart into smaller pieces when it contacts a hard surface. Some projectiles (5.45x39, .308) are designed to hold together and "yaw" in tissue, causing damage by tearing/slicing. 5.56 hits very quickly, and the force of that impact causes the bullet to tear apart, delivering many smaller fragments into a target to inflict a wider wound. Now, some larger, slower 5.56 bullets have the same kinetic energy (F=MA), but if they impact at a slower speed, even though they're larger, the round will yaw and tumble in flesh. Since the 5.56 is a relatively small bullet, that tumbling may not hit a vital area and cause incapacitation.

That said, I'm primarily a recreational/target shooter. I like 5.56 because it is a cheap, fairly accurate round to poke holes in paper, not because I want to shoot at targets other than deer.

Small fast bullet breaks when it hits things, shards spread out in a cone.
Larger slower bullet holes together, tumbles around.

>menards
Yankboi detected

>Menards
>Northern midwest
>Yank

I'll fucking knock out all your fucking teeth and then I'll get the fattest fucking cow around to sit on you.

Projectile strikes target, and penetrates 8 inches

Then bullet yaws and breaks up along the cannelure of the jacket.

Jacket fragments, throwing tiny shards of metal throughout the body

High velocity rifle rounds create an effect called hydrostatic shock, which is basically a shockwave that causes injuries beyond the path of the projectile. The fragmentation allows the maximum energy to be dumped into the target, instead of exiting out

Id love to see you try fatboy.
Nothing quite like the feel of a right cross smashing into the fattened chin of a shitbird yank.

the length of a 20" doesnt seem like an issue until you have to pie corners in a cramped building. Then you have to start short stocking (pic related) if you dont want your muzzle sticking into whatever you're trying to clear.

Attached: shortstocking.jpg (1023x560, 56K)

Small caliber rounds have noticeably more fleet yaw than bigger calibers, as in it spins around not quite concentric to the flight path. It's like spinning a top that's not perfectly straight up, the tip goes in a circle path. Being small caliber they are also less stable (imagine the stability of a wide top vs a thin top) and when they impact on almost anything they yaw or tumble quickly and violently. When regular FMJ rounds like this impact a target and tumble they break, typically at the cannelure, and fragment into bits causing multiple divergent would tracts. People make a big deal about the "Fragmentation threshold" but even under those velocities SCHV rounds still tumble and have decent terminal effectiveness.

M855 was known to have very inconsistent fleet yaw characteristics, which meant it would take longer to yaw in flesh. So above or below the "fragmentation threshold" they had poor performance but most attribute this to shorter barrels. This lead to the whole "ice-pick" thing in Somalia that is incessantly meme'd. To combat this the US military has gone to projectiles that don't depend on fleet yaw at all, namely M855a1, MK318, Brown Tip (TSX), and agencies have gone to rounds like the Speer GoldDot, TSX and FBIT3. Not only do these rounds not depend on fleet yaw for terminal effectiveness, they have better terminal effectiveness at significantly lower velocities, ~1800-1900 fps, and have better barrier penetration.

Attached: FleetYaw2.jpg (526x518, 76K)

>Yank
Sorry did Minnesota violate your ancestor at Gettysburg or something? Really sounds like the gay weather down south is fucking your brain. Yanks are to the east, you dumb shit.

20'' w/ lightweight profile
16'' mid-length
11.5'' SBR

Anything else is dumb.

We're better than the South and we fucking know it.

20" since i can attach a pokey bit to it.

20" rifle length, 16" middy, and if I needed a shorty it'd be an 11.5" carbine gas. The 14.5 pinned fags are cancer.

Attached: IMG_20180702_194032.jpg (1743x1307, 781K)

He's a eurocuck not a southerner, you fucking mouthbreathing retard. It's why he's so goddamned retarded and obsessed with America.
inb4 vietnam memes

Attached: OBSESSED.png (1280x720, 1.63M)

Don't some guys in JSOC use .300 blackout though? An SBR makes a lot more sense if you can use a round optimized for it.

Specops have been using shortened rifles since Vietnam and earlier. Due to their missionset, maneuverability and weight savings are prioritized. There's a reason the US military isn't issuing MK18s to every soldier however.

>Implying I need to be aware of anyone outside of the US at any time
>Implying dumb southerners don't also call us yanks

I mean really you're right but now I am literally ill from the idea of a foreigner talking at me.

yeah that mission set being a lot of close quarters action so they dont have to do I would argue from a civilian standpoint you're basically never going to have to shoot someone far away enough to necessitate a 20 inch AR, you're more likely to end up having to shoot someone in your house etc where using a 20" is doable but uncomfortable if you're actually clearing correctly.

I'm thinking of doing a 20 inch build in .223 Wylde. What's the benefit of tighter twist rates? I was thinking of 1:8 but I've got no idea what I'm talking about there

18in rifle length gas. Squeezes an extra couple fps out of soft shooting config.

Faster twist rates will be able to stabilize heavier and longer projectiles. 1:8 goes up to around 77gr depending on the projectile.

How would it fair with 55 grain?

They'll work fine.

I don't disagree but I also don't think it's wise to clear your house alone. Unless you're moving towards a family member, clearing your house is fucking stupid. Call the cops, take up a defensive position, you're not fucking Seal team 6.

Higher twist rates stabilize heavier bullets.

Good to know. Ideally I'll be shooting 69-77 grain projectiles but for just punching paper at 100 I want to be able to just dump m193 or other cheap .223

I have a 16" mid gas. I kept the A2 sight on for a while because I was going through a "I-can-still attach-a-bayonet-if-I-want phase". Got rid of A2 sight and bought a free float handguard, and mounted a DD front sight.

If I'd do it again:
>16" dissipator
>free-float hand guard behind A2 sight (I really like iron sights) for that dank sight radius

>Unless you're moving towards a family member
thats mostly what I was thinking of, the other part being little bumps/noises that arent obviously a person (time to call the cops) but are worth further investigation. I agree with the call the cops sentiment if thats not that case.

Longer bullets.
With the need for lead free bullets in some areas bullets will need to be longer to keep the same weight.

Dissipator. Not my rifle, was cleaning it for someone and couldn't help take photos of it.

Attached: IMG_20180609_105111.jpg (4081x2605, 3.9M)

Are those reliable? There isn't much barrel after the gas block sobthe dwell time where the gas block is under pressure is really short. I know some AR pistols have reliability issues for the same reason.

A E S T H E T I C

this guy knows

They use a carbine length gas tube under the hand guard. The front sight post is just for the handguard and...well the front sight.

>this guy knows
I want one for myself so bad.

Attached: IMG_20180609_105235.jpg (4233x2505, 3.96M)

>sat on by a cow

don't tempt me user

I have a 20", 18" and some 16" and the 16" makes for a great balance

What's wrong with an 18" rifle ?

What manufacturer should I get the dissipator from? Does it matter ?

I really don't know too much about modern ones expect that Windham and I think Aero make them. Also that the Windham one has a 1:9 twist and know nothing of the Aero ones. The Colt in the photo was a one off run made for the California Highway Patrol...I think Bushmaster made some for them as well.

rifle is designed around a 20" barrel the dwell time helps reliability

14.5 pinned is retarded because you’re making it a pain in the ass to switch out some things on your rifle for negligible weight and length savings. 14.5 is still shit for close quarters.

All of the above

Attached: 20180625_182251.jpg (2560x1440, 1.19M)

20" is life. As the good lord intended it.

I'm impressed by the amount of good taste ITT

16" faux dissi, midlength gas, 1:7

Ask me how many rounds/years since I've cleaned with zero malfunctions...

only a problem if the gas port is too small.
gas problems in di systems are rare events nowadays

thats retarded lol

20", Because I'm a manlet and having a long rifle makes up for my small dick.
Also, I like bullpups, which are already compact and easy to handle.

Green Mountain literally makes the worst barrels in existence

>s o y
yes you are

14.5 carbine
16 carbine is too long for my tastes
Have various non intermediate caliber rifles, so a 20 is unnecessary.

Built to shoot gooks in a bush is just fine

Attached: _20180629_000241.jpg (4140x5240, 2.6M)

You should die

Honestly just looking at the chart the Dissipator seems objectively the best. Minimum barrel length, maximum gas length, with a collapsible stock as well it would be great.

Attached: 05257128_zi.jpg (1760x2040, 439K)

Thoughts on 18 inchers? I can't find a complete 18" a2 upper for the life of me

14.5" midlength or 10.5" carbine.

What are you on about? Their AK barrels are trash, but their AR barrels are good kit.

That isnt what a Dissipator is. A dissipator is an A2 gas block at rifle length (for longer sight radius) but with a midlength gas system. The trick with gas systems is to have the bullet stay in the barrel for the correct amount of time. Too much, and the gun will be heavily overgassed and beat itself to death like 16 inch carbines. To little, and the gun will be undergassed and not cycle reliably.

Anything that isnt 20 inch rifle or 14.5 carbine should not be allowed to exist.

20" is nice
I love the look of a dissipator. Maybe a psuedo dissy with the A2 post and a mid length gas system.
Also a big fan of 14.5 pinned, and 10.5 with the A2 post

>That isnt what a Dissipator is. A dissipator is an A2 gas block at rifle length (for longer sight radius) but with a midlength gas system.
No, it's not.

what you are describing is a mock dissapator

14.5 midlength