Worthwhile AR Upgrades

[LSUTiger]

I have a S&W M&P 15T, 2010 vintage with the 1/9 carbine gas barrel and a semiauto bolt. It has the 11" troy rail and is freefloat quad rail with troy flip buis's. The gun feel and looks like a solid build, better than some of the sport models I've seen around lately. Just my opinion.

I love the gun and it shoots great, I've had no problems so far, not as accurate as I would like but thats probably my fault , I get about 2-4MOA with an unmagnified Eotech @100 yards shooting Federal XM855 62 gr and Winchester RA556M855 62 gr.

It is by no means an undesireable gun but it has the least desirable specs of any of my AR's. I have some 1/7 mid lengths and carbine lengths with M16 auto bolt also.

I want to upgrade the barrel to a 16" 1/7 twist Mid Length Gas and also get an M16 Bolt. Cost is about $280-300 for DD or BCM barrel, $13 for the tube, $ for the low profile gas block and $140 for the BCM M16 Bolt. Altogether about $460-ish. To get the same upper with a quad rail minus the troy flip Buis is in the $600-700 range.

My goal is really to get the 1/7 twist, it keeps bugging me, maybe for no good reason but the 1/9 seems like it could be a limiting factor in ammo choice, Midlength vs carbine not that big a deal to me but why not get a middy if I am going spend money on something new (price is the same)? Also, the M16 bolt is desirable but also not a limiting factor so its not totaly necessary.

I will shoot primarily the 55 gr xm193 and 62 gr M855 stuff but want to be able to shoot higher weight ammo if needed.

Which of these upgrades are really worthwile? ( I believe they all are but maybe I should spend the money on ammo or something else.)

Any opinions?

[cajunautoxer]

What type of trigger you got on the S&W? I use JP and Giesselle 3G

White Oak Armament 1/8 twist

[LSUTiger]

The trigger is the standard out of the box single stage I believe, I think their newer VTAC model come with an upgraded 2 stage trigger and 1/8 barrel mid length.

Why 1/8 over 1/7?

[comp73]

Trigger for sure and look into getting one of the newer chamber sizes like 223 wylde or BCM's 556 NATO match chamber.

1:8 twist will stabilize a smaller bullet better than a 1:7. Keep in mind, its not technically the weight of the bullet, but the length, that impacts the accuracy in regards to rifle twist rate.

BCM and Noveske sell barrels with these specs. Larue also uses a 556 wylde chamber and they get their barrels from Lothar Walther, and you can buy barrels from LW directly. I do not know if Larue does the cutting and chambering or if it is done at the LW factory, so YMMV.

[LSUTiger]

my original thought was to keep it cqb setup but now I am thinking SPR type setup might be an option.

18" or 20"?

would my troy 11" rail be too short or would a longer rail be necessary?

[cajunautoxer]

What are your plans for this AR. You said this isn't your only one you have. If your looking for better accuracy I'd try better ammo first. I get nice results from Hornaday's Match grade 75gr. My buddy loves his Black Hills. I'd try that before buying a new barrel. But yes trigger first

[gigag04]

Hint:

It's not the barrel.

[LSUTiger]

Are you suggesting it could possibly be my shooting skills? Just kidding! I know I could benefit from more range time, better optic, better trigger, better ammo, but mostly better shooting skills/range time, but that wasn't the reason for upgrading, just wanted a 1/7 to be the same as all the other kids in the neighborhood.

Then spending more money on upgrades alway brings up a world of options to spend it on.

[The Annoyed Man]

I will shoot primarily the 55 gr xm193 and 62 gr M855 stuff but want to be able to shoot higher weight ammo if needed.

I've only ever had 1:9 barrels. I'd like to get a 1:7, but mostly because I want a chrome lined barrel, and they all seem to be 1:7 these days. Now, I had a long conversation the other day with one of the "Ask the Experts" guys at Brownells, and AR barrel twist was one of the topics. He told me that the only reason the U.S. military uses 1:7 barrels these days is because they stabilize tracer ammo well, but that virtually ALL NATO partners are using 1:9 barrels in their 5.56 NATO chambered weapons. 1:9 will stabilize anything from about 55 to around 68-69 match bullets very well, including the 62 grain 855 penetrator. So unless you plan to shoot a lot of 77 grain SMKs, there isn't a whole lot of ballistic reason to need that twist rate for a carbine length barrel. That doesn't mean that it's a bad idea, but it might be a little oversold. The guy I was talking to had 1:8 twists in his personal AR barrels.

Before he worked for Brownells, he worked for Federal at Lake City, and he said that he sometimes fired as much as 15,000 rounds in a day during testing (using more than one weapon). He sounded like he knew what he was talking about.

[PBratton]

Before he worked for Brownells, he worked for Federal at Lake City, and he said that he sometimes fired as much as 15,000 rounds in a day during testing (using more than one weapon). He sounded like he knew what he was talking about.

I WANT that job! How much did he have to pay Federal for it?

[cyphur]

Aside from marginal bragging rights, I see no benefit to having an M16 bolt. If yours is mil-spec as is, you should be fine.

Unless you want to shoot a bullet you cannot stabilize with your 1/9, you will not gain any inherent accuracy from a 1/7 unless you dramatically upgrade the quality in hopes of tighter specs.

If you want better groups, tune or upgrade your trigger, practice shooting, and perhaps get some magnified optics.

[The Annoyed Man]

Before he worked for Brownells, he worked for Federal at Lake City, and he said that he sometimes fired as much as 15,000 rounds in a day during testing (using more than one weapon). He sounded like he knew what he was talking about.

I WANT that job! How much did he have to pay Federal for it?

I know, huh?

[rwi862]

Built one earlier this year w/ almost the same specs on your want list... but also added a CMC trigger. The trigger is great, clean break, easy install, and less expensive than alot of other trigger upgrades. I would buy one again.
http://www.cmctriggers.com/

[OldCannon]

Built one earlier this year w/ almost the same specs on your want list... but also added a CMC trigger. The trigger is great, clean break, easy install, and less expensive than alot of other trigger upgrades. I would buy one again.
http://www.cmctriggers.com/

[koolaid]

If you are only planning on having the one AR, I would recommend getting a magnifier for your EOTech.

I have one of the older style 4X flip-to-side ones, and it has probably been the best purchase I've made in terms of making the rifle more fun/useful for both the range and home defense.

Another consideration before you replace your 1/9 barrel, is that the 1/9 will do a better job with a .22 conversion if you ever decide to go that route.

Anyway, just my opinion.