Opinions on precision shooting ar build

[peter209]

Like I said if I get moa I'll be happy but if I can go sub moa then my bolt guns might not get shot for a while. I was liking at the bushnell 5-15x only because I can get a great deal on it

[captbilly]

Best velocities for 5.56/.223 are over 30"

You may want to upgrade to a 20" barrel. Best velocities for 5.56/223 are out of a 20" barrel.

Though it is true that a 20" barrel will have better velocity than a 16" barrel, it is also true that the velocity will continue to increase almost without limit as the barrel increases. I have seen test data that pretty clearly demonstrates that muzzle velocity increases on .223 and .308 as barrel length increases to any practical length. Most long range .223 shooters (800-1000 yard) use 26" barrels in order to get a decent balance between muzzle velocity and accuracy.

[FMJBT]

Though it is true that a 20" barrel will have better velocity than a 16" barrel, it is also true that the velocity will continue to increase almost without limit as the barrel increases. I have seen test data that pretty clearly demonstrates that muzzle velocity increases on .223 and .308 as barrel length increases to any practical length. Most long range .223 shooters (800-1000 yard) use 26" barrels in order to get a decent balance between muzzle velocity and accuracy.

That depends largely on powder type and bullet weight. This study done by Gemtech using NATO spec 62 grain shows that a 20" barrel yielded the highest velocity. At 21", there was a drop of over 100 FPS followed by a second burst of acceleration towards 24" where their test barrel ended. Velocity loss between the 16" and 20" barrel was less than 200 FPS:

http://www.dtic.mil/ndia/2010armament/WednesdayCumberlandPhilipDater.pdf

Within reason, pretty much anything you can expect a 5.56 rifle to do can be done with a 16" to 18" barrel without having to resort to using overly long and heavy barrels. I'd only go with something over 20" if I were shooting for 700+ yards using handloads with slower burning powder like Varget.

[atolax25]

Though it is true that a 20" barrel will have better velocity than a 16" barrel, it is also true that the velocity will continue to increase almost without limit as the barrel increases. I have seen test data that pretty clearly demonstrates that muzzle velocity increases on .223 and .308 as barrel length increases to any practical length. Most long range .223 shooters (800-1000 yard) use 26" barrels in order to get a decent balance between muzzle velocity and accuracy.

16" is fine. Shorter the better actually for accuracy.

Yes, one shouldn't always equate higher velocities to better accuracy. Higher velocity just equals a longer range that the bullet will remain stable in flight. If you want a 20" barrel you'll have to also get it correspondingly thicker so that it is more rigid and won't flex as much.

[peter209]

So to my understanding 16" bull barrel will be adequate for 100-300 yards as long as I find a quality round that it shoots well or start loading them myself?

[peter209]

Also, what would the Burris 536 best be used for?

[ArmedCMT]

...I was looking into a 20" barrel before I bought my current upper but a guy at my lgs told me it would be overkill at the distance I wanted to shoot. I also, got a beyond great deal on the new 16" bull upper I got.

What is this "overkill" you speak of?? So did you buy your 16" from the dude that told you 20" would be "overkill"? If you had decided that a 20" is what you wanted did he have a 20" to sell you?

[FMJBT]

So to my understanding 16" bull barrel will be adequate for 100-300 yards as long as I find a quality round that it shoots well or start loading them myself?

If you have a 1:8 or 1:7 twist, you should be good to go out to about 650-700 yards with a 16" barrel using heavier bullets like the 69, 75 and 77 grain BTHP.

Also, what would the Burris 536 best be used for?

I'm not sure I could find a use for a fixed 5X BDC scope. It's magnification and reticle design really limits it's usefulness to shooting medium sized targets at distances found at typical rifle ranges (100-300 yards). Seems like it has the mid range area covered decently, but lacks both close in or long range ability. If they made it like an Elcan Spectre that would go from 1X to 5X at the flip of a lever, it would be a great scope. At a fixed 5X power though, it's just too limited.

[peter209]

If I remember correctly, the guy who told me that said that for the distance I was going to shoot at a 16" bull upper with a 1/9 twist could get me sub moa with good ammo. He called a 20" overkill but wasn't exactly opposed to it. I believe I remember him saying I might get slightly better results but not noticeably at the distance I was planning for. I didn't buy the upper from him. A close family friend sold me the upper since it was just sitting in his safe with no real intention of using it. The guy has a few different ar builds and wasn't planning on building another so he sold it to me for the price of his admission into the competition he won it at. It was less than $200 so I couldn't pass it up

[peter209]

Yes he did have a stainless 20" heavy barrel to sell me but like I said I couldn't pass up the deal on the 16" I got

[Thorax]

So.....

How many of you guys have seen a 16" barrel on a military sniper type rifle ?

Yea, I thought so.

Accuracy takes bullet stability, period.
The longer the barrel the greater the stability....to a point.

You are not going to see any sub 20" barrels at any national match unless it is specifically required by the rules.
24" is about the minimum they shoot if they have a choice.
Most prefer 26" to 31" tubes. Some are even longer.

Quit flat out not knowing, or lying intentionally, telling the guy that short barrels are more accurate, they are not.

[FMJBT]

So.....

How many of you guys have seen a 16" barrel on a military sniper type rifle ?

Yea, I thought so.

M110-C:

[Thorax]

M110-C:

Sniper rifle ?

No.

It's a DMR.

[sffred]

IMHO its fine that u use a 16" barrel, as long as its medium contour or thicker. To the OP hopefully your 16" is a middy.

Shorter, thicker barrels do not "whip" as much as longer barrels. Easier to group also IMO (up to 100yrds). With longer barrels you can better groups, but it becomes a bench/prone gun. I think the OP is trying a precision Recce/Recon "style" build. (Given the fact, he wants a 5x)

If the OP wants a fixed scope, I would recommend a minimum a fixed 10x (swfa, bushnell elite, etc...). I believe just having a stronger magnification would improve your groups significantly compared to a 5x.

Oh, I would veer away from the ergo stock and get a stock that that is consistent (prs, efx-a1, etc...).

[G21Shooter]

IMHO its fine that u use a 16" barrel, as long as its medium contour or thicker. To the OP hopefully your 16" is a middy.

Shorter, thicker barrels do not "whip" as much as longer barrels. Easier to group also IMO (up to 100yrds). With longer barrels you can better groups, but it becomes a bench/prone gun. I think the OP is trying a precision Recce/Recon "style" build. (Given the fact, he wants a 5x)

+1 You really need to figure out your purpose of use(POU) for the setup. If you are only shooting off a bench and want to go for maximum accuracy, get a heavy bull barrel 18 or 20 inches. 16 inch will be fine within 200-300 yards. More weight the better for a bench gun.

If you want a RECCE/RECON set up that you want to be more "mobile" able to take coyote hunting and even be used as a run and gun type rifle, you want a medium profile stainless barrel.