Anyone install a takedown kit on their AR and what do you think of it?

[Geofois]

Maybe I'm interpreting things wrong but someone said barrel length and boat tail bullets have nothing to do with accuracy. I would imagine if one barrel is made of licorice and the other is nice then yes but both barrels being of similar quality that the longer the barrel the increased velocity therefore the less time spent in the air being affected by all other variables not to mention speed is energy if that helps.

Boat tail having less drag I would think would also help for accuracy since the more air is a factor the more unpredictable a bullet will be versus shooting in a vacuum. Not that a boat tail will eliminate all air but the less drag the more predicable right? Maybe they didn't mean to say has "nothing" to do with accuracy.

[tonyxcom]

The OP is bringing this up because he thinks he needs a 24" barrel to make repeatable shots at 800y. 4-6 MOA is HUGE at 800y considering he can't even make repeatable hits at 500y without swapping barrels.

OP, I'd think less about shooting beyond 500y until you can consistently shoot sub MOA at 100y.

[Geofois]

I'll check again but I was dead cent at 50 and my groupings were pretty tight at 100. I got bored plinking at 100 so starting hitting the steel at 200 then 300 then 400 and so on. Since it's just steel beyond 100 for me then other than not seeing the dust kick up I can't tell how far off. I was thinking with a 16 inch barrel versus a heavier longer barrel I should be able to do what you say at 100y then I could be more reliably hitting the steel way out there. I'm not hitting paper beyond 100 so maybe it doesn't matter so much since no way to measure accurately. I'm just leaning still. Thanks everyone for your input.

[ar15barrels]

I don't know about others, but a few MOA is untenable.

Totally fine for indoor range shooters who drive Miatas or take the train/bus to get to the range.

[W.R.Buchanan]

The only advantage to the longer barrel is increased velocity.

According to 2 ballistic calculators my 24" barrel should yield @ 2780fps with 77 gr bullets and 23.8 gr of BL-C2. This is not the highest velocity, it is the velocity that has the bullet in the barrel for the correct amount of time with respect to the barrels harmonics. IE: the bullet comes out when the barrel is in the same position every time.

Pumping the charge up to 25 or 26 gr would yield a Velocity of over 3000 fps but accuracy would be unusable.

My 55 gr loads with 25 gr of BL-C2 are unusable for long range at about 1.5 -2 MOA just because the barrel harmonics don't like that velocity.

A lot more to this than point and shoot. Going to a good Long Range Class will help you understand all the fine points.

Then you get to figure out the wind ! which will take a while !

Randy

[Mute]

Totally fine for indoor range shooters who drive Miatas or take the train/bus to get to the range.

Maybe if they use it as a club.

[ar15barrels]

Maybe if they use it as a club.

3 moa at 25yds is like 3/4" on target.
Totally fine for the indoor range shooters...

[kcheung2]

Maybe I'm interpreting things wrong but someone said barrel length and boat tail bullets have nothing to do with accuracy. I would imagine if one barrel is made of licorice and the other is nice then yes but both barrels being of similar quality that the longer the barrel the increased velocity therefore the less time spent in the air being affected by all other variables not to mention speed is energy if that helps.

Boat tail having less drag I would think would also help for accuracy since the more air is a factor the more unpredictable a bullet will be versus shooting in a vacuum. Not that a boat tail will eliminate all air but the less drag the more predicable right? Maybe they didn't mean to say has "nothing" to do with accuracy.

I said most of those things so I'll try to explain. In long range, consistency is the goal. aka repeatability. If a projectile performs the same way every time, then how much it drops or how long it spends in the air doesn't matter because you can always adjust your dope to compensate. Neither velocity nor BC is a factor in consistency. Powder charge, case volume, bullet construction, barrel harmonics, barrel quality, those things are factors. (among others)

Consistency is based on a whole bunch of other things too, but not necessarily what you think. Shooting a bullet faster just means shooting it faster. It doesn't mean it's more likely to hit a bullseye. Energy does not equal accuracy. Air isn't a factor. Wind is, which is perhaps what you meant. That can be somewhat offset by using a heavier projectile so it's less resistant to wind, which leads to another misconception that heavier projectiles are inherently more accurate. No, they're just heavier. Their advantage is that they resist wind better. But in a windless environment or at distances where wind doesn't matter (200yds & under) then there is no difference. If you take up reloading, you'll notice there are generally 2 accuracy nodes, and even the higher one is rarely at max charge.

Drag is a factor, but not in the way you think. A lower-drag projectile (higher BC) will stay supersonic longer, which is good because once a projectile crosses the transonic barrier (drops below the speed of sound) the shockwave will catch up to it and disrupt it. At that point it becomes very unstable & loses all accuracy.

In practical use, my .22 rifle is just as accurate as any AR at 50 yds, despite having much less energy. That's because at those distances, neither wind nor drag is a factor. But at 100 yds the .22 will lose because the projectile drops below the sound barrier around 75 yds. (Unless I use std velocity .22, which stays subsonic the whole time) Likewise, at 200 yds my 5.56 AR is just as accurate as my .308 AR because both projectiles are still supersonic & wind won't have as much time to cause much drift.

But if velocity isn't a factor, why is long range stuff like Mk262 loaded so hot? Like I said above, dropping below the sound barrier is real bad for consistency, so long range ammo is loaded at max velocity so that it stays supersonic longer, so it's still reliable (and fatal) beyond 600yds or so. But at 400yds and closer (I just picked a distance, there's no specific math behind exactly 400), there's no advantage to it vs other match ammo.

I did not discuss bullet construction, but that's also very important. The point is that like others said, there's lot's of nuances & fine points to precision shooting. Just saying a longer barrel or a boat tail taper = accuracy is wrong. They affect other variables which can improve or detract characteristics of consistency, but they by themselves won't get you there.

If you're into photography, it's analogous to saying that a lower f/stop leads to better pictures. Or if you're into cars, it's like saying wider tires makes your car go faster.

[BarrettM99]

OP, for your intended purpose, just having a separate upper is the easiest solution.

If you want to go LR/ULR, a bolt gun is the way to go. You can build something very respectable for a reasonable price.

[Geofois]

Yes thank you Barrett. I accepted that a few posts back. I was going to say I should change the title since my thread has evolved into me asking about barrels now hehe.

Thank you Kcheug2 for that explanation. I remember reading about the speed of sound having an affect but couldn't remember exactly why but that makes sense since I was aware of it's affect on jets as they do the same thing. I didn't mean to sound like those things "just" as in "only" affect it one way but it does sound like a higher speed can and typically does at the longer ranges help with repeating results if the speed stays supersonic to the target. I was thinking of groupings also versus bullseye but I get what you're saying. I imagine if the drag is predictable then boat tail and non boat tail make no difference if you can account for it. I was thinking non boat tail would be less predictable but sounds like I was wrong and it's just a matter of knowing it's ballistic coefficient.

From your experience if I'm shooting basic 55gr federal is there even a need to get a 24" barrel for hitting metal targets out to 600 yards or is a 20" with a 1:9 twist just fine? Or is the 16" that I already have going to give me results that are just as repeatable so basically just as accurate? I should change the title of my post hehe.

[saki302]

A warning-

If you build a separate upper with its own optics, it will magically grow into a complete rifle.

You have been warned!

-Dave

[Geofois]

I think I'm going to end up with 4 uppers so I better plant one of them in the ground to grow an lower =). I'll use one lower with the rifle buffer for the 20" and 24" barrel uppers and a carbine lower for the 9mm and 16" upper. Then after I'm going to make upper angels on the floor by moving my arms and legs.

[ar15barrels]

From your experience if I'm shooting basic 55gr federal is there even a need to get a 24" barrel for hitting metal targets out to 600 yards or is a 20" with a 1:9 twist just fine?
Or is the 16" that I already have going to give me results that are just as repeatable so basically just as accurate?

The biggest problem here is the 55gr blaster grade bullets.
If you want more precision (to hit smaller targets at longer distances), you absolutely need to be using better quality bullets.

Simply shooting match ammo will allow you to shoot smaller targets (the legs of the pigs instead of the bodies) with whatever length barrel you already have, but longer barrel like a 20" or 24" will certainly help with the wind which is likely going to give you fits at 400-600yds when you are trying to stay on the legs/feet of the pigs at Angeles.

If you are happy just hitting the big red circle, none of this matters as that's a 6moa target...



For size comparison, the little yellow target sitting atop the red target in the picture above is a 1moa target.

Legit precision rifle shooters shoot 6" targets (1moa) at 600yds.
Anybody with the minimum of equipment and skill should be able to hit the 36" targets (6moa) at 600yds.

[BajaJames83]

tried it a few times they are hot garbage yes they make them easy to use but if you have any kind of malfunction its a **** show....

go featureless hinestly even when the BB was a thing featureless was better

[Ki6vsm]

I started reading this and ended up losing track of what it's about. Hah. Still don't know what these takedown "kits" are that were mentioned. But if you travel with your upper and lower separated, you might think about getting one or more of these covers from Raven Concealment. Does a great job of keeping gunk out of the upper plus it keeps your BCG from flying out of there unexpectedly. I think securing the BCG is its main advantage. That and with the little tab/extension on the back end you can just stand up the assembly, lean it against your car/truck etc if need be and not worry about fouling anything.

I have seen similar plastic lower-receiver covers for keeping the FCG clean, which is kinda more important I guess. But they are a lot more expensive. Might just be best to make sure your carrying case is nice and clean inside at all times.