1/7 vs. 1/9 twist AR barrels

[Thursty]

Alright internet friends, I need counsel.

I have ARs, mostly for plinking, 90% of the time I'm running standard run of the mill 55 grain FMJ ammo. My what I would consider "do all" gun is a 16 inch Smith and Wesson M&P15, one of their original "duty grade" rifles, not the newer sport line. I've upgraded the rifle over the years, but there are a few things I don't like about it, I don't care for the handguard (15 inch older Aero handguard), it is heavy, and its a 1/9 twist barrel. Now, this rifle is a solid 1.5 MOA gun with bulk ammo, so I've got nothing to complain about there, but it doesn't shoot some of the heavier stuff well, and I would appreciate the option of having some sort of long range AR, or the option to use my general purpose rifle at extended ranges. 

Here's my quandary: I went to the local shop today and picked up a BCM handguard. I like that handguard, and it is much lighter, so that solves 2 of my issues with the gun. While there one of the guys, who I like and respect his opinion, talked me into a 14.5 inch barrel with a 1/7 twist, then I thought well, I may as well buy an upper and the gas system, I've got an extra BCG kicking around and I'm sure a charging handle somewhere. So I left with a much more expensive bill than I had planned on. Now my buyers remorse is telling me to take the barrel and other stuff back and to just swap the handguard onto my Smith, but the other part of my brain is telling me to build out the 14.5 upper, then later on put an 18 inch barrel in the Smith and use it as a sort of SPR upper. Whatever I do I'm just building uppers and using the same lower, as it is currently set up exactly how I want it. 

So. What do I do internet?

[Omega]

If length isn't an issue, a 14.5" barrel won't do much for you except maybe a little less fps.  The twist is important for heavier bullets though, 1/7 is all I buy when buying barrels.  Having said that, my 10.5" barrels do quite well and are pretty accurate.  10.5 is the shortest I have built, though I have an 8" barrel somewhere but it's probably not going to be built unless I run out of things to do. I have a S&W flattop too, and am not sure the twist on that one, but that was my first AR and didn't pay attention to those things back then because 55 grn was probably the heaviest bullet back then, at least the heaviest I had seen. 

[Alleycat72]

If I were putting together an sbr or long range ar15 in 5.56, it would be a 1 in 7. If I wanted to shoot lighter bullets a coyotes out to 300ish yards, I'd do 1 in 9. BTJM

[DHF]

I have gotten very specific on a couple things for any barrel/upper I now purchase for a rifle that will be shooting bulk ammo.  It has to have a 223 wylde chamber and it has to have a 1/8 twist.  Does it really matter?  Maybe not but there is not a shortage of options for high quality barrels within these two specs, so why compromise.  If I'm building something specific, I'd build accordingly or if someone lists something for sale that is dirt cheap, I may grab it but otherwise it needs to hit these two marks. 

[DL126]

11 hours ago, DHF said:

I have gotten very specific on a couple things for any barrel/upper I now purchase for a rifle that will be shooting bulk ammo.  It has to have a 223 wylde chamber and it has to have a 1/8 twist.  Does it really matter?  Maybe not but there is not a shortage of options for high quality barrels within these two specs, so why compromise.  If I'm building something specific, I'd build accordingly or if someone lists something for sale that is dirt cheap, I may grab it but otherwise it needs to hit these two marks. 

Same here.

Latest one used this ...
https://www.armorally.com/shop/ballistic-advantage-223-wylde-fluted-premium-series-20-dmr-barrel/
3070 FPS with Hornady 55gr

[gregintenn]

You can’t have too many ARs!

[Alleycat72]

1 hour ago, gregintenn said:

You can’t have too many ARs!

Challenge accepted 

[leroy]

1 hour ago, Alleycat72 said:

Challenge accepted 

Collect em all..!

leroy...

[phiferran]

I have them all and currently prefer the 223 wylde in 1X8,  

[juliangunney]

Horses for courses really, what do you want the rifle for? 223 Wylde has been mentioned and it's a great choice, 223 was designed around a 20" barrel so if you want decent velocity.......... 

I just completed a 22Arc build, 1:7 twist and 24" barrel as I wish to fling good BC bullets long distances. On the other end of the spectrum I have a 300 BLK with 7.5" barrel, great for subs. They all have a reason to be in your safe!!!!  

[Thursty]

Well I think I settled it for myself today. I might build out a 1/7, but it’s not a priority. I threw down this 5 round group with steel cased TulAmmo. Put down a similar but very slightly larger group with ZSR bulk ammo, and a 1.5 inch group with bulk 62 grain green tip. This was at 50 yards, but pulling out the flyer that is about 1 MOA. I can’t argue with that for the absolute dirt cheapest ammo you can find. 

[phiferran]

Good shooting!!!

[doug77]

An old friend of mine once said keep the number in even dozen that way you know how many you have.