I'm building my first AR15. I want it to be a SPR. I want it to be a tac driver.. I think i have decided on a 18in barrel. What do you suggest I look for in a barrel?

Rifling

 

Sorry, couldn't resist.

 

Good luck with the build

1/7 1/8 1/9

Rifling

 

Sorry, couldn't resist.

 

Good luck with the build

 

 

Are you looking for a true spr or gonna be using it as a bench rifle? I would look for the right trigger first then worry about the barrel. Then match the barrel twist with the round you're most likely going to shoot. Make sure its the right profile for the type of shooting you will be doing.

do you want it to be an actual SPR (clone) or just an 18" with magnified optics?

Black Hole Weaponary has many choices, I just bought an 18" 5.56 1-8 Target Crown SS Black Shot Peened, haven't assembled yet, waiting on Handguard.

18",  1:8 twist,  Stainless,  .223 Wylde chamber, Rifle length gas system, Medium contour, threaded with target crown.  Thread protector or compensator.  Rainier, Odin Works, Nordic, White Oak.  If money is no object, Shilen, Noveske and JP are quite good.

 

Technically, an SPR barrel is spec'd with a 1:7 twist but this limits your optimal bullet weight to 77gr match grade ammo.  It will not shoot 62gr XM855 well at all and you can forget about 55gr.  Going with a 1:8 you can still shoot 77gr with very good accuracy but will also shoot 62gr green tip with acceptable accuracy.  Basically a 1:8 gives you a greater range of bullet weights whereas a 1:7 restricts you to the heavier pills.

 

 

Are you looking for a true spr or gonna be using it as a bench rifle? I would look for the right trigger first then worry about the barrel. Then match the barrel twist with the round you're most likely going to shoot. Make sure its the right profile for the type of shooting you will be doing.

I will not be upgrading a trigger till I shoot 1 plus rounds... I have a spikes trigger

do you want it to be an actual SPR (clone) or just an 18" with magnified optics?

Idk I just want a cool ass rifle that I hit targets at 100 yards plus

Idk I just want a cool ass rifle that I hit targets at 100 yards plus

You can do that with a 14.5" barrel (pinned comp to make 16") carbine set up for CQB and a red dot sight.

 

I have gone out to 300 yards with mine with no issues.

You can do that with a 14.5" barrel (pinned comp to make 16") carbine set up for CQB and a red dot sight.

 

I have gone out to 300 yards with mine with no issues.

 

Silhouette sized or medulla oblongata sized targets?

 

6" steel circles, from a braced standing position.

 

BCM upper, SSA trigger, 4moa Aimpoint T1.

6" steel circles, from a braced standing position.

 

BCM upper, SSA trigger, 4moa Aimpoint T1.

 

Pretty good! Is that consistantly ?

 

Guess 6"  and 4 moa works well.  See the shadow of the steel around the dot and good to go!

I understand that it's not a precision shot. It is well within the stated capabilities of a rack grade M4 shooting non-match ammo, with non magnified optic. It's also not a precision rifle, it's a carbine set up for fighting/CQB.

 

The points I was trying to make were:

1) His stated purpose for the rifle left a lot of room for interpretation for how to get it done.

2) He doesn't have to go all SPR or specific type. A "general" purpose rifle that could be a decent shooter, a HD weapon, and a competition rifle would suit his needs

3) He could probably reach his goal without spending as much as he thinks. Going out to 200 yards, he likely won't see much of a difference between a precision barrel and say a standard BCM barrel - so why pay for it?

Pretty good! Is that consistantly ?

 

Guess 6" and 4 moa works well. See the shadow of the steel around the dot and good to go!

3 out of 4 on average if shooting relatively quickly.

 

Bright orange/yellow/green surveyors paint on the steel helps a lot.

 

You can zero a RDS so the very edge of the dot at 12 o'clock is the aiming point. Helps to get a little more precision out of it, but you can still use the whole dot when speed counts up close.

I understand that it's not a precision shot. It is well within the stated capabilities of a rack grade M4 shooting non-match ammo, with non magnified optic. It's also not a precision rifle, it's a carbine set up for fighting/CQB.

 

The points I was trying to make were:

1) His stated purpose for the rifle left a lot of room for interpretation for how to get it done.

2) He doesn't have to go all SPR or specific type. A "general" purpose rifle that could be a decent shooter, a HD weapon, and a competition rifle would suit his needs

3) He could probably reach his goal without spending as much as he thinks. Going out to 200 yards, he likely won't see much of a difference between a precision barrel and say a standard BCM barrel - so why pay for it?

 

Very true.  What he's looking for is not that "Precision".

My 20" HBAR shoots 6"@ 300 with irons all day. and no FF handguard

Look at the Rainier Arms 18" Match SPR profile 1/8 twist and Wylde chamber..got mine for $250..about $10 more than a BCM 14.5"

I'd recommend the Rainier SPR barrel or the WOA SPR barrel both chambered in .223 Wylde 18".  Good experience with both and they are good prices for quality barrels.  

Gentlemen! Gentlemen! Gentlemen!

 

When the 223/5.56 cartridge was developed...

 

What barrel length was it designed around?

Ooooooo oooooooo oooooooo I know this!!!

 

But more importantly, there is this:

 

MK 262 VELOCITY DATA

__________________________________

 

 

7.5" 2053 FPS ... 10.5" 2363 FPS

DIFFERENCE 310 FPS

DIFFERENCE/INCH 103 FPS

 

10.5" 2363 FPS ... 14.5" 2576 FPS

DIFFERENCE 213 FPS

DIFFERENCE/INCH 53 FPS

 

14.5" 2576 FPS ... 16" 2669 FPS

DIFFERENCE 93 FPS

DIFFERENCE/INCH 62 FPS

 

16" 2669 FPS ... 18" 2769 FPS

DIFFERENCE 100 FPS

DIFFERENCE/INCH 50 FPS

 

18" 2769 FPS ... 20" 2818 FPS

DIFFERENCE 49 FPS

DIFFERENCE/INCH 25 FPS

 

 

 

M855 VELOCITY DATA

__________________________

 

7.5" 2244 FPS ... 10.5" 2639 FPS

DIFFERENCE 395 FPS

DIFFERENCE/INCH 132 FPS

 

10.5" 2639 FPS ... 14.5" 2861 FPS

DIFFERENCE 222 FPS

DIFFERENCE/INCH 56 FPS

 

14.5" 2861 FPS ... 16" 2938 FPS

DIFFERENCE 77 FPS

DIFFERENCE/INCH 51 FPS

 

16" 2938 FPS ... 18" 3046 FPS

DIFFERENCE 108 FPS

DIFFERENCE/INCH 54 FPS

 

18" 3046 FPS ... 20" 3061 FPS

DIFFERENCE 15 FPS

DIFFERENCE/INCH 7.5 FPS

 

 

XM193 VELOCITY DATA

_________________________________

 

 

7.5" 2364 FPS ... 10.5" 2755 FPS

DIFFERENCE 391 FPS

DIFFERENCE/INCH 130 FPS PER INCH

 

10.5" 2755 FPS ... 14.5" 2984 FPS

DIFFERENCE 229 FPS

DIFFERENCE/INCH 57 FPS PER INCH

 

14.5" 2984 FPS ... 16" 3075 FPS

DIFFERENCE 91 FPS

DIFFERENCE/INCH 61 FPS

 

16" 3075 FPS ... 18" 3245 FPS

DIFFERENCE 170 FPS

DIFFERENCE/INCH 85 FPS

 

18" 3245 ... 20" 3254 FPS

DIFFERENCE 9 FPS

DIFFERENCE/INCH 4.5 FPS

 

Those last 2" aren't giving you much juice for the squeeze.

 

A real Mk12 SPR is spec'ed to 18" barrel - just sayin'

Ooooooo oooooooo oooooooo I know this!!!

 

Come on HE  I know current ammo isn't geared for the originally configured barrels which were 1:12 and sucked.

 

Thanks for not shoving that one up my ...

Yeah that was kinda like saying when gasoline was first invented how did you put it into the horse

 

World keeps changing

You can do that with a 14.5" barrel (pinned comp to make 16") carbine set up for CQB and a red dot sight.

 

I have gone out to 300 yards with mine with no issues.

I have clue how people shoot that far with irons. . I can't see past 59 yards clearly. . My goal is build a rifle to my specs leaning towards a SPR. . I would like to shoot 55 g bc it's easy to find.

 

I have clue how people shoot that far with irons. . I can't see past 59 yards clearly.

 

no one can see that clearly that far, but you don't need to, you need to see your sights clearly and the target fuzzy. You may use larger targets but that doesn't mean you'll get dramatically larger groups.

I have clue how people shoot that far with irons. . I can't see past 59 yards clearly. . My goal is build a rifle to my specs leaning towards a SPR. . I would like to shoot 55 g bc it's easy to find.

 

55gr M193 and SPR are mutually exclusive.  What you want is an old skool M16ish rifle with a 20" 1:12 bbl if shooting 55gr pills is what you want.

55gr M193 and SPR are mutually exclusive. 

 

Huh? since when was that law passed?

55gr M193 and SPR are mutually exclusive. What you want is an old skool M16ish rifle with a 20" 1:12 bbl if shooting 55gr pills is what you want.

???

 

My 1/9 shoots 55gr just fine.

So does my1/7

  I'm sorry, I must have missed something.  I thought the OP wanted to build an SPR.

OP...build yourself an SPR..get a 1/8 18" barrel which should throw most bullets fine..get a decent optic so you dont have to squint...and enjoy shooting it till it aint fun anymore..dont overthink it