Standard hand guard or free float?

[PeterCartwright]

Any of you started with the standard spring-loaded plastic hand guard and then changed it out for a free float guard? Did you see an accuracy difference? What are your experiences? (from a NOOB)

PC

[PlatoCATM]

The most significant accuracy differences will be seen while slung or otherwise exerting force on your barrel. Usually the difference won't hurt a fighting carbine, but some like dual role rifles for varminting and training classes or what have you.

[rob_s]

I'm working on an article on the myths of the free-float tube for the AR system.

End-use of the carbine will play a big role in all of your firearm accessory choices. If you can tell us more about how you intend to use the gun w can offer a little bit better guidance.

If you're working with a precision rig the effect on accuracy of a sling/bipod/rest/etc. may be of concern. For the way that most people run the M4-style carbines those concerns are somewhat minimized, often due to the inability of the barrel, ammo, optic, and shooter to hold any kind of group that would be affected in any meaningful way by those kinds of outward forces or due to the end-use not being one of supported shooting.

Once you exclude those going to a rail system strictly for aesthetic reasons, most do so as a way to attach what they consider to be mission essential accessories to the gun. A cop, soldier, or home defender wants a light, a night hunter wants an IR illuminator, many want a vertical foregrip of some sort, some want an alternate sling attachment point, etc. To that end, there is a greater possibility of effecting POI when accessories are added or removed from a non-free-float system than a free-float. Additionally, free-float systems tend to be of a higher overall quality and tend to provide rails that are closer to the correct dimensional specs and offer a smaller overall profile. This isn't to say that there aren't cheap/crappy free-float systems, but there are far less non-cheap/crappy non-free-float systems.

[PeterCartwright]

Great questions. First some background on the gun: This is my first AR, built primarily from RRA parts. My primary departure from RRA is an White Oaks Arms 16" barrel (1/7" twist and Wylde chamber) with a fitted bolt. This is a mid-length system. My trigger group comes from a box/stock DPMS kit.

I've mounted an Eotech 516 on the flat top receiver. I've been a bit disappointed so far with the way this gun performs with various 55 gr. ammo. I guess part of the motivation for "switching out" relates to seeing if I can get a bit more accuracy with "economy grade" 55 gr. fodder (e.g. Federal's .223 55gr. and even PMC 55 gr. stuff). To be fair, I haven't shot much 5.56 ammo through this gun.

Use? Guess the best answer is "general purpose". I'll use the gun in an occasional 3 gun match and informal shooting. We're over run with coyotes as well. And, of course, there's always keeping zombies off the front porch.

I have a collection of match grade Hornady and Sierra match bullets and eventually I'll do some load development. I expect this match grade, 7" twist to do quite well with these longer bullets, but I'd really like it to do "adequately" (well enough for 3 gun matches) with more economical ammo. Am I still believing in the tooth fairy?

PC

[rob_s]

WOA stainless barrel?

Your intended use sounds pretty typical. I would probably be inclined to install a FF rail on that gun, especially if it is the stainless barrel.

I'd work up some loads, or buy some factory 75-77 grain ammo like Black Hills and see what you're getting for accuracy before writing it off. I haven't shot 55 grain ammo for groups in a very long time (2+ years at least) but I get Wolf 75 grain to group under 1" at 50 yards from a bipod in a 1:7 BCM 16" barrel. I think sub-2 MOA with that combo is pretty damn good personally, especially given the knucklehead pulling the trigger. ;)


You might want to take a look at some of the new breed of FF rails/tubes hitting the market like the Blackheart, Troy TRX Extreme (not standard) (http://store.troyind.com/TRX_BattleRails_s/51.htm), and the Viking Tactics version of the Troy (http://www.vikingtactics.com/handguard.html). Lighter, lower cost, less real-estate that you might not be using anyway...

[PeterCartwright]

WOA stainless barrel?

Your intended use sounds pretty typical. I would probably be inclined to install a FF rail on that gun, especially if it is the stainless barrel.

I'd work up some loads, or buy some factory 75-77 grain ammo like Black Hills and see what you're getting for accuracy before writing it off. I haven't shot 55 grain ammo for groups in a very long time (2+ years at least) but I get Wolf 75 grain to group under 1" at 50 yards from a bipod in a 1:7 BCM 16" barrel. I think sub-2 MOA with that combo is pretty damn good personally, especially given the knucklehead pulling the trigger. ;)


You might want to take a look at some of the new breed of FF rails/tubes hitting the market like the Blackheart, Troy TRX Extreme (not standard) (http://store.troyind.com/TRX_BattleRails_s/51.htm), and the Viking Tactics version of the Troy (http://www.vikingtactics.com/handguard.html). Lighter, lower cost, less real-estate that you might not be using anyway...

Yup. The barrel's stainless. I don't think WOA makes anything else. It's my understanding that they fabricate their barrels from Wilson blanks.

PC

[djegators]

Some people tend to like the full rails with covers for better heat protection, esp if shooting a lot outdoors. It also gives you more options later for mounting accessories, if your needs change.

[ntxyankee]

Who, other than Surefire makes a non-free float rail for the M4 style of carbine.

The purpose would be to cover the port with the rail.

Also, does the Pri fat boy gas tube help with a 16 inch M4 government profile style barrel?

Thanks

[OTO27]

I have not been able to see any diference in accuracy after installing a free float rail on my 6920. However the main reason why I did it is so I could mount my eotech a bit further forward and not worrying about it loosing zero.

[Kabob]

Who, other than Surefire makes a non-free float rail for the M4 style of carbine.

A ton of companies:

Daniel Defense
Double Star
Knights Armament
Midwest Industries
Troy Industries
Yankee Hill Machining

And probably several more (those are just what's on BCM's (http://www.bravocompanyusa.com/Tactical-Handguards-Non-Free-Float-s/53.htm) website).

[Zanshin]

You are sending yourself on a wild goose chase trying to get better groups with 55 gr FMJ fodder. I believe that M193 is 2.5 moa ammo in the first place? Work up a load with some SMKs and watch that WOA barrel get better than 1 moa accuracy.

I save 55 gr FMJ to push down my chrome lined carbine barrel. I am under no illusions that I am going to get tight groups out of a 16 inch chrome lined M4 profile barrel. I shoot for combat accuracy, and for fun.

For my ARs with stainless match grade barrels I won't fire 55 gr FMJ from the barrel. I paid good money for a match grade barrel, and match barrels don't last forever like chrome lined barrels. You get (depending on the barrel) 2-4,000 rounds before it starts to lose some of its accuracy potential. With a match grade barrel I work up a load and then that's what i shoot from it.

By all means free float the barrel, but don't go looking for better groups from 55 gr FMJ just because the barrel is floated. Shoot better ammo.

[PeterCartwright]

You are sending yourself on a wild goose chase trying to get better groups with 55 gr FMJ fodder. I believe that M193 is 2.5 moa ammo in the first place? Work up a load with some SMKs and watch that WOA barrel get better than 1 moa accuracy.

I save 55 gr FMJ to push down my chrome lined carbine barrel. I am under no illusions that I am going to get tight groups out of a 16 inch chrome lined M4 profile barrel. I shoot for combat accuracy, and for fun.

For my ARs with stainless match grade barrels I won't fire 55 gr FMJ from the barrel. I paid good money for a match grade barrel, and match barrels don't last forever like chrome lined barrels. You get (depending on the barrel) 2-4,000 rounds before it starts to lose some of its accuracy potential. With a match grade barrel I work up a load and then that's what i shoot from it.

By all means free float the barrel, but don't go looking for better groups from 55 gr FMJ just because the barrel is floated. Shoot better ammo.

Well, guess I'm discovering the breadth of my ignorance. I assumed that a stainless barrel would be more resilient than a chrome lined alternative. I really don't need "match grade" accuracy. So what's the "combat grade accuracy" life of a stainless barrel?

PC

[rob_s]

I think the point he's making is that if you throw less than stellar ammo down the pipe, the barrel is not the weak point in the accuracy equation it's the ammo. A high-quality stainless barrel *might* group M193 tighter than an issue M4 barrel will, but it's only going to be able to improve the group size so much.

ammo+barrel+optic+shooter=accuracy

(there are lots of little sub-sets in there (overall firearm, trigger, etc.) but those four are the big ones IMHO.

[Showbart]

I'm glad Rob is doing an in-depth article on this. For me it's not so much about accuracy lost or gained but about weight and tactile feel. I just don't feel the trade off in weight with most rails is worth it, then they don't feel good in hand so heavy rubber covers are added. When all is said and done there's a desire to lighten up with the pencil bbls.

[shadow65]

For my ARs with stainless match grade barrels I won't fire 55 gr FMJ from the barrel. I paid good money for a match grade barrel, and match barrels don't last forever like chrome lined barrels. You get (depending on the barrel) 2-4,000 rounds before it starts to lose some of its accuracy potential. With a match grade barrel I work up a load and then that's what i shoot from it.

2-400 rounds for a stainless barrel?

[Zanshin]

Keep in mind that accuracy is relative to the shooter.

If you are a match shooter or an accuracy nut who must shoot sub-moa groups, your useful "life" out of a match grade barrel is going to be much shorter than someone who isn't measuring success by fractions of an inch. Serious highpower shooters shoot a barrel for one season, and then swap the barrel to a practice upper for the next season. In that way every year they shoot a brand new barrel in competition, and last year's barrel for practice.

When I say that a match barrel gets shot out in 2,000-4,000 rounds, that is by match shooter standards. If you are a casual shooter looking for good accuracy the barrel will last long past that. You just won't notice the accuracy loss, but it will be there for those who shoot well enough to notice it. Even so, when a match barrel starts to "go", sometimes it is not even noticeable at short distances (100-200 yards).

I didn't mean to scare you about the quality of a stainless barrel. Plenty of military issue rifles have SS barrels.. pretty much anything accurized like an Mk12, SDM-R, etc. Its the guns that shoot auto that have the chrome lined barrels.

I was just trying to point out what Rob said more clearly in far less words. The weak link in your shooting is not the lack of a free float rail. It is crappy ammo. If want to shoot 55 gr FMJ for fun have at it (we all do). If you want to see what you and your rifle can "do", you need to shoot better ammo.

[EzGoingKev]

If you plan on mounting a bipod on it then I would say that a free floating rail would be the way to go.