Barrel selection

[RubberBullets 65]

So im shopping for my first build... Im considering building my upper as well so the barrel selection is the first major part id like to get out of the way. I hear 1:9 is the preferred, but a friend suggested 1:7 twist... Any thoughts regarding one or the other?

 

Length being the second question. I dont necessarily want it to sweep my house for HD, but I dont want something too long to be cumbersome while outdoors. 16" im guessing?

 

Chrome vs SS? I know expense is the deciding factor, but for something that will get a few thousand rounds thrown through her in its lifetime is the price increase justified to upgrade?

 

Lastly...chambering.. chamber for 5.56 or .223? .223 is what im sure id end up using the majority of the time, but you can use .223 in a 5.56 and not the other way around. Would it make more sense to chamber for the 5.56 and have the flexibility, or would I be doing the wrong thing by not chambering in the round Id be using more frequently. Im all about ability to adapt and if I could shoot either or without instance that would be right down my ally. Thanks ahead of time for any input.. just a n00b trying to put an AR build together.

[YWHIC 18]

1/7 twist gives more bullet GR variety then a 1/9 twist will. Some match barrels are 1/8.

 

16" or 14.5" would be fine.. 14.5" requires a pin/welded Comp/Brake.. but since you in NJ you need that (pin/weld) done anyway on any AR barrel with threads..

 

There are post-ban barrels with no threads and that would work also..

 

223 in 5.56 chamber is GTG.. but NOT 5.56 in 223 chamber..

[RubberBullets 65]

 

 

223 in 5.56 chamber is GTG.. but NOT 5.56 in 223 chamber..

 

So i assume it would make more sense to get a 5.56 and have the flexibility of using both ammo correct?

[YWHIC 18]

Correct.. that or a match barrel with 223 WYLDE chamber which can also run 556 ammo..

 

Just a note that ALOT of places sell loose barrels.. Palmetto, Midway, BCM, Spikes, DSG.. then you just need to find an upper receiver, BCG (bolt carrier group), gas tube, and some other things..

 

You need a special vise block/claw for like $55 and some type of barrel wrench $25-30 to tighten the barrel nut properly with a torque wrench..

 

Places like ADCO and others can assemble all the parts at a cost if you run into a jam or realize you can't afford all the tools for a possible 1x usage.. or the welding end of it (if needed)..

[RubberBullets 65]

I can see myself building a second one later on down the line. Would these tools be helpful in later projects such as a saiga conversion perhaps? I would hate to buy the tools for a 1 or 2 time use.

[YWHIC 18]

The AR clamshell for upper ($48) is for AR15 uppers (that are not billet) (some billet uppers have odd angles).. Other wise you would need a CLAW (about same cost) that goes thru the takedown pins..

 

Most go with forged AR uppers.. unless you want something special and $$$.. difference in cost on the AR uppers is $70-300..

 

You would need a BARREL wrench $30 and again thats for standard AR barrel nuts..

 

The AR lower is roll pin punches, blue tape, visegrips, small hammer..1/4" clevis pin from HDepot (or razor blade) and PATIENCE..

 

I did Saiga conversions (4) for myself 2 years back.. I used a drill, dremel, and hammer for that.. gotta love AK's..

[Old School 611]

 

 

Twist and barrel length...

 

I shoot 1:9 barrels and the heaviest bullet I shoot is 68gr so 55gr and 62gr(the most common commercial loadings) should shoot fine out of a 1:9. Uncle Sam says the 62gr stabilizes better for distance in a 1:7 But I'm sure somebody will comment on that. I stabilize a 68gr fine out to 300yd.

 

Chamber - If this is your only AR go for 5.56 for versitility and the pending zombie apocalypse.

 

Unless you're going into the jungle you can do without chrome lining. But ok to have.

 

Normally I'd say 18-20 barrel for accuracy at 100+ yds but since I shot about 1 1/2 group with a 16" and irons the other day I can't really say that. If yor going to shoot 200yd or better you may want a longer barrel.

 

 

[Zell959 40]

1:8 is a pretty good compromise on twist ratio that tends to give you the best of both worlds. Only downside is that you're generally talking about a stainless steel barrel, as 1:8 doesn't seem to be offered in chrome lined barrels for some reason.

 

If you decide you want to go with a chrome lined barrel, you're back to 1:9 or 1:7. For me, the 1:7 is the better fit because it has the flexibility of letting me shoot 75-77gr rounds and I don't see much need to have a barrel that is 'optimized' for 55gr bullets because all of the rounds I shoot in that weight are inexpensive surplus & steel rounds that I don't really expect to be accurate in the first place [regardless of the barrel they're shot through].

 

However, I can see some instances where someone might want 1:9. For example, if you're looking to do some varmint hunting and need the rifle to shoot lightweight varmint bullets with a high degree of accuracy, the 1:9-1:12s might actually be a better fit for your needs.

[Old School 611]

1:8 is a pretty good compromise on twist ratio that tends to give you the best of both worlds. Only downside is that you're generally talking about a stainless steel barrel, as 1:8 doesn't seem to be offered in chrome lined barrels for some reason.

 

If you decide you want to go with a chrome lined barrel, you're back to 1:9 or 1:7. For me, the 1:7 is the better fit because it has the flexibility of letting me shoot 75-77gr rounds and I don't see much need to have a barrel that is 'optimized' for 55gr bullets because all of the rounds I shoot in that weight are inexpensive surplus & steel rounds that I don't really expect to be accurate in the first place [regardless of the barrel they're shot through].

 

However, I can see some instances where someone might want 1:9. For example, if you're looking to do some varmint hunting and need the rifle to shoot lightweight varmint bullets with a high degree of accuracy, the 1:9-1:12s might actually be a better fit for your needs.

 

Yes 1:8 is nice but as you alluded to pricey.

 

The most inexpensive ammo is loaded in 55gr so 1:9 IS the way to go.

 

When was the last time you shot 75-77gr bullets. Most times won't run through the magazine. We're talking AR right?

[Shocker 151]

Mk262 fits in AR mags

[alowerlevel 77]

Yes 1:8 is nice but as you alluded to pricey.

 

The most inexpensive ammo is loaded in 55gr so 1:9 IS the way to go.

 

When was the last time you shot 75-77gr bullets. Most times won't run through the magazine. We're talking AR right?

 

 

Theres plenty of 75-77gr ammo out there that works just fine in AR mags. Hornady, Black Hills, Federal, Nosler, Prvi Partisan all make 75-77gr .223/5.56. And like Shocker said some military/special forces use mk262 in thier rifles which uses a 77gr Sierra Matchking bullet.

 

 

A 1/7 will shoot 55gr just as good as 1/9 will, now if you want to shoot lighter varmint (<50gr) rounds then the 1/9 will be better, but if you want to shoot the 70gr and up stuff then your gonna want the 1/7. But for common .223/5.56 ammo (55-62gr) either twist will work just fine.

[Old School 611]

Theres plenty of 75-77gr ammo out there that works just fine in AR mags. Hornady, Black Hills, Federal, Nosler, Prvi Partisan all make 75-77gr .223/5.56. And like Shocker said some military/special forces use mk262 in thier rifles which uses a 77gr Sierra Matchking bullet. A 1/7 will shoot 55gr just as good as 1/9 will, now if you want to shoot lighter varmint (&--#60;50gr) rounds then the 1/9 will be better, but if you want to shoot the 70gr and up stuff then your gonna want the 1/7. But for common .223/5.56 ammo (55-62gr) either twist will work just fine.

OK I stand corrected. I shoot mostly reloaded ammo and man those heavy bullets don't leave much case capacity

 

Edit: And your correct, 68gr is the heaviest bullet I'm really happy with in a 1:9

[Zell959 40]

 

 

Yes 1:8 is nice but as you alluded to pricey.

 

The most inexpensive ammo is loaded in 55gr so 1:9 IS the way to go.

 

When was the last time you shot 75-77gr bullets. Most times won't run through the magazine. We're talking AR right?

 

Only bullets I'm shooting right now are 75gr hornady and 77gr Sierra. We are talking ar 15. Fitting into standard magazines is no problem

[Old School 611]

Only bullets I'm shooting right now are 75gr hornady and 77gr Sierra. We are talking ar 15. Fitting into standard magazines is no problem

 

Pm Sent I'd like to pick your brain.

[Vlad G 345]

Another endorsement for 1/7 here, they shoot 55gr (and even 52gr) just fine, I see little reason today to get a 1/9 barrel seeing how the trend has been for heavier and heavier bullets, with 62's being the light ones now. I like chrome lined because I don't like to clean my guns.

[Old School 611]

Another endorsement for 1/7 here, they shoot 55gr (and even 52gr) just fine, I see little reason today to get a 1/9 barrel seeing how the trend has been for heavier and heavier bullets, with 62's being the light ones now. I like chrome lined because I don't like to clean my guns.

 

Damn it! I've been intending to use my 24" SS 1:9 for tactical 300yd matches(it's really my chuck gun) but you guys are having me consider a SS barreled 1:7 for tact so I can go to the heavy bullets. 68gr is the heaviest I shoot satifactorily out of the 1:9 and I'd really like to eliminate some more wind drift.

 

I did pick up another NM lower to work off of.

 

Please suggest a 12 step program.

[Vlad G 345]

Damn it! I've been intending to use my 24" SS 1:9 for tactical 300yd matches(it's really my chuck gun) but you guys are having me consider a SS barreled 1:7 for tact so I can go to the heavy bullets. 68gr is the heaviest I shoot satifactorily out of the 1:9 and I'd really like to eliminate some more wind drift.

 

24" is way too long for most matches I've shot, simply because most matches have a mix of long range and short range stages, and a lot of the short range stages are close in, with obstacles, odd shooting positions, etc. For that kind of stuff 18" is as long as I'd go, 20" if you REALLY want it. I use a 16".

 

I did pick up another NM lower to work off of.

 

Please suggest a 12 step program.

 

There isn't one, short of going broke you keep building them, or so I hear. I personally don't have this problem ... <cough> ... gotta go, UPS is at the door with ... hmm .. a fruit basket.

[DevsAdvocate 112]

I also suggest a 1x7 twist. It does the cheaper low grain stuff, and heavy grain stuff if you want to use that for HD.

[Old School 611]

24" is way too long for most matches I've shot, simply because most matches have a mix of long range and short range stages, and a lot of the short range stages are close in, with obstacles, odd shooting positions, etc. For that kind of stuff 18" is as long as I'd go, 20" if you REALLY want it. I use a 16". Different game Vlad. 300 from a rest or bipod. There isn't one, short of going broke you keep building them, or so I hear. I personally don't have this problem ... &--#60;cough&--#62; ... gotta go, UPS is at the door with ... hmm .. a fruit basket.

[Vlad G 345]

Different game Vlad. 300 from a rest or bipod

 

Okie, I'd call that a sniper match not a tactical one then. Not that tactical matches don't shoot at that distance, its just that it isn't the only thing.

[Dan 177]

Here's my personal observations from internet research (take it for what it is).

 

My twist of choice is 1:8 or 1:7. I can still shoot cheap 62gr plinker stuff out of them with good accuracy out to a few hundred yards, then load up some heavy gr hand loads when I want to. I'm playing with 69gr SMK's currently, but also want to try some heavier stuff soon, especially 77's.

 

1:12 - 55gr and below

1:9 - 62gr and below

1:8 - 80gr-69gr

1:7 - 90gr - 69gr

[Vlad G 345]

1:12 - 55gr and below

1:9 - 62gr and below

1:8 - 80gr-69gr

1:7 - 90gr - 69gr

 

I'm curious why people think 1 in 7 is not just peachy for things like 55gr. Personally I have yet to hear of a 1 in 7 barrel that won't shoot 55gr bullets just fine.

[RubberBullets 65]

Thanks for the input. Im leaning towards just picking up a complete upper instead of the hassle of buying the tools for building the upper. Leaning towards a 16" chrome 1:7 chambered in 5.56 for greater versatility with rounds and bullet weight. Id like to buy one with a dual or quad rail on the handguard... havent narrowed down a manufacturer, but im trying to sell myself on the stag left handed 2htl for $730 its a 1:9 but i think something in my arsenal should be made for us gifted individuals that shoot southpaw. Any other suggestions as far as manufacturers go with the same setup for less dough? (im sure the RH'd ones would sell for less) im not opposed to having a rh upper, but if im paying say $650 for an upper, why not shell out the rest for a true LH.

 

http://www.stagarms....products_id=221

[DevsAdvocate 112]

Here's my personal observations from internet research (take it for what it is).

 

My twist of choice is 1:8 or 1:7. I can still shoot cheap 62gr plinker stuff out of them with good accuracy out to a few hundred yards, then load up some heavy gr hand loads when I want to. I'm playing with 69gr SMK's currently, but also want to try some heavier stuff soon, especially 77's.

 

1:12 - 55gr and below

1:9 - 62gr and below

1:8 - 80gr-69gr

1:7 - 90gr - 69gr

 

1x7 does stabilize 55gr... at least that's what I've been led to believe.

[Zell959 40]

1x7 does stabilize 55gr... at least that's what I've been led to believe.

 

It absolutely can. The ranges he's giving are sort of rough, and to say only as heavy 62gr for 1:9 is selling it short.

 

It's also worth mentioning that the ability to stabalize a projectile with a certain amount of spin is actually a function of bullet length, not what it weights. Since weight is usually a pretty good approximation of how long a bullet is, bullet weight is usually a pretty good indicator to go off of. If you were able to find a relatively short bullet design that weighed 75gr, you'd likely have a pretty decent chance of stabalizing it out of a 1:9 barrel. It might not be the most accurate variety of ammo for that barrel, but it wouldn't be guaranteed to keyhole either. I use to have a Stag Arms model 2 upper in 1:9 and I never experienced keyholing with 75gr rounds. Now, it liked 68-69gr reloads better, but the 75's I tried were never a disaester.

 

The 1:7 twist ratio was originally a standard that emerged out of a US military need to allow 14.5" M4 barrels to stabalize a particular variety of tracer round that was notably longer than standard 5.56 ammunition. I.E. 1:7 was the solution needed to fire a particularly long round out of a relatively short barrel and it may not necessarily need to be quite that fast to stabalize the kinds of "heaver" rounds we usually have in mind as civilian shooters.

 

One other means that "slower" twist barrels will often overachieve is a longer barrel. For reasons that exceed my understanding of aerodynamics, projectile spin is less of an issue at higher velocities, so a bullet rotating at 1:9 but exiting the muzzle faster than a bullet rotating at 1:7 can apparently achieve comparable stability in its trajectory. As an example of this, my buddy has a Colt target rifle with a 20" barrel. It's 1:9 twist, but he has no issues with stability when he tries out my 77gr sierra reloads & 75gr sierra reloads. Now, it still seems to shoot tighter groups with 69s, but I wouldn't categorize his results with my heavier bullets as anything less than 'decent', which wouldn't be possible if the bullets were becoming unstable at any point. Now, it's worth mentioning that this was only 100 yards and might not be the case at 200/300/etc.

 

I guess my point is just, don't shy away from really testing out what a given barrel can shoot based just on the "average" performance range of 1:X barrels. For the majority of civilian shooters with barrels in the 16"+ range and no 80gr tracer rounds in their ammo can, I'm inclined to consider the twist ratio decision a matter of deciding what kind of bullet you want your rifle to shoot "best" instead of what your rifle won't be able to shoot at all

[RubberBullets 65]

 

 

I guess my point is just, don't shy away from really testing out what a given barrel can shoot based just on the "average" performance range of 1:X barrels. For the majority of civilian shooters with barrels in the 16"+ range and no 80gr tracer rounds in their ammo can, I'm inclined to consider the twist ratio decision to be more a matter of deciding what kind of bullet you want your rifle to shoot "best" instead of what your rifle won't be able to shoot at all

 

A very good insight and I think it will help make my decision making a bit easier. Thank you

[Dan 177]

1x7 does stabilize 55gr... at least that's what I've been led to believe.

 

I'm not saying they won't stabilize, I'm just saying from my research, I've outlined what twist rate corresponded to the optimal bullet weight. A 1:9 may stabilize a 69gr bullet with decent results, just that it won't be the best match from what I have been reading. I'm no expert, and is all IMO.

 

I do shoot 55gr and 62gr all day long in my 1:7 BCM upper all day, and it does great. But that's me just me plinking using a red dot scope at 100 yards. Would I pick a 1:7 to shoot 55/62gr for precision out at 400 yards, no I wouldn't, I'd load it up with some 75/77gr rounds for that.

[raz-0 1,259]

I'm not saying they won't stabilize, I'm just saying from my research, I've outlined what twist rate corresponded to the optimal bullet weight. A 1:9 may stabilize a 69gr bullet with decent results, just that it won't be the best match from what I have been reading. I'm no expert, and is all IMO

 

One thing to point out is that in general, you cannot make a determination about how well a barrel of twist rate X will shoot a bullet of weight Y. It isn't JUST about the weight. It is also about the bearing surface of the bullet. A heavy bullet with lots of bearing surface may stabilize out of a barrel that a heavy bullet of the same weight with a VLD design won't. Bullet profile and construction matters more than you would think.

[Turbotezza 1]

It's actually the length of the projectile that matters. Since the bore size is fixed, the only way to gain bullet weight is to go long. Long and thin projectiles need more spin and time to stabilize than short fat ones.

[Dan 177]

Exactly turbo, generally , the heavier the round, the longer it is when referring to rounds of the same type/caliber.