I'm going to be getting a new upper soon.  It's going to be a carbine length.

YES, carbine length.  Because I wan't my stuff to look like the GI's stuff, that's why. (of course it wont anyways )

It'll be used for Home defense / hunting / target shooting.

It'll probably be a flat top M4 type barrel, probably the 16", maybe.

I've heard it said for a fighting weapon, non free floating is better.  I can't see why, but I wanted to get all your all's  input.

I'm sure it's been debated before but I figure it gives others an opportunity to state their reasons if they didn't before.

I thank you for the advice in advance.

Quoted:I've heard it said for a fighting weapon, non free floating is better.

I disagree.  Free floating has no disadvantages except a little bit more weight up front.

Quoted: Quoted:I've heard it said for a fighting weapon, non free floating is better.   I disagree.  Free floating has no disadvantages except a little bit more weight up front.

A free floated barrel is harder to take apart.

Quoted: A free floated barrel is harder to take apart.

depends on which one.

removed

I've heard it said for a fighting weapon, non free floating is better. I can't see why, but I wanted to get all your all's input.

That's a little out of context. I don't think anyone would purposely Non free float. what the deal is that for a 300 meter fighting carbine, the advantages of free floating which are mostly improved accuracy are minimal and you would not really benefit much from them . Especially if you shoot Surplus GI or Wolf Ammo. If you bought a Carbine that allready had it , that would be one thing, but to purposely go out and buy the set up expecting to shoot dime size groups at 100 yds is unrealistic. Most stock carbines will shoot better on paper then the guy behind the trigger.... remember it's not a sniper rifle.....

Quoted: I've heard it said for a fighting weapon, non free floating is better. I can't see why, but I wanted to get all your all's input. That's a little out of context. I don't think anyone would purposely Non free float. what the deal is that for a 300 meter fighting carbine, the advantages of free floating which are mostly improved accuracy are minimal and you would not really benefit much from them . Especially if you shoot Surplus GI or Wolf Ammo. If you bought a Carbine that allready had it , that would be one thing, but to purposely go out and buy the set up expecting to shoot dime size groups at 100 yds is unrealistic. Most stock carbines will shoot better on paper then the guy behind the trigger.... remember it's not a sniper rifle.....

Yeah, there's no reason NOT to free float, it's just not ESSENTIAL for minute-of-bad guy out to 200 yards.

Quoted: Quoted: I've heard it said for a fighting weapon, non free floating is better. I can't see why, but I wanted to get all your all's input. That's a little out of context. I don't think anyone would purposely Non free float. what the deal is that for a 300 meter fighting carbine, the advantages of free floating which are mostly improved accuracy are minimal and you would not really benefit much from them . Especially if you shoot Surplus GI or Wolf Ammo. If you bought a Carbine that allready had it , that would be one thing, but to purposely go out and buy the set up expecting to shoot dime size groups at 100 yds is unrealistic. Most stock carbines will shoot better on paper then the guy behind the trigger.... remember it's not a sniper rifle..... Yeah, there's no reason NOT to free float, it's just not ESSENTIAL for minute-of-bad guy out to 200 yards.

Well, that's kind of my point.  My colt A2 can shoot the BH 52 bthp's consistently under 2" and more like 1.5".  It doesn't do that with all ammo, but the right one's it will.  Steve at ADCO said once he thought every AR is about a 1 moa gun.  Probably if everything is working properly and something with the barrel is not screwed up.   To me, it doesn't seem all that crucial unless you were going to be like prairie dog hunting or sniping of some sort.  Do you agree?  But like I said, even with a normal set up, I've gotten good groups with the right ammo.  I guess I gotta decide if I wan't it  varmint accurate or  more realistic 2-3 moa on a regular basis.  What do you think?

Quoted: Yeah, there's no reason NOT to free float, it's just not ESSENTIAL for minute-of-bad guy out to 200 yards.

I would have to agree with you 100%.

It's a bonus, but certianly not required.

Hell, I would be willing to bet most guys could not tell the difference.

That being said, all of my AR's have LaRue rails.  

Quoted: Quoted: Quoted: I've heard it said for a fighting weapon, non free floating is better. I can't see why, but I wanted to get all your all's input. That's a little out of context. I don't think anyone would purposely Non free float. what the deal is that for a 300 meter fighting carbine, the advantages of free floating which are mostly improved accuracy are minimal and you would not really benefit much from them . Especially if you shoot Surplus GI or Wolf Ammo. If you bought a Carbine that allready had it , that would be one thing, but to purposely go out and buy the set up expecting to shoot dime size groups at 100 yds is unrealistic. Most stock carbines will shoot better on paper then the guy behind the trigger.... remember it's not a sniper rifle..... Yeah, there's no reason NOT to free float, it's just not ESSENTIAL for minute-of-bad guy out to 200 yards. Well, that's kind of my point.  My colt A2 can shoot the BH 52 bthp's consistently under 2" and more like 1.5".  It doesn't do that with all ammo, but the right one's it will.  Steve at ADCO said once he thought every AR is about a 1 moa gun.  Probably if everything is working properly and something with the barrel is not screwed up.   To me, it doesn't seem all that crucial unless you were going to be like prairie dog hunting or sniping of some sort.  Do you agree?  But like I said, even with a normal set up, I've gotten good groups with the right ammo.  I guess I gotta decide if I wan't it  varmint accurate or  more realistic 2-3 moa on a regular basis.  What do you think?

Hit the nail on the head. If you're already planning to add rails, most systems free float anyway, but I wouldn't drop $300 on a free floating rail system for a HD type rifle if I didn't need to hang anything on it.

Although, if you use sling tension for steading the rifle (ala Highpower type competition), then attaching it to a free floated forearm is a good idea (again, only if your purpose is dime size groups.

If I have a choice between a floater rail and a non floater, I'll take the floater. It might cost a wee bit more, but its more durable and stable, most FF rails are lighter than non FF rails, and I wouldn't have to worry about POI shift at all. Would POI shift matter in a fight? I doubt. But it will matter when I screw around at the range, and there are no negatives associated with a free float tube save the barrel change issue, and that doesnt matter to me.

Quoted: Quoted: Quoted:I've heard it said for a fighting weapon, non free floating is better.   I disagree.  Free floating has no disadvantages except a little bit more weight up front. A free floated barrel is harder to take apart.

You need to try harder to find a reason not to have a FF barrel..

another big bonus of the FF rail is they don't get nearly as hot after a few quick mag dumps. living in the arizona desert you find out what heat is really about.

even the M4 HG's get a little to warm for my liking on a nice summer day after 3 or 4 mags of rapid fire.

of course for you northern guys, a little extra heat is great most of the time. keeps your hands from turing into ice sicles.

Quoted: another big bonus of the FF rail is they don't get nearly as hot after a few quick mag dumps. living in the arizona desert you find out what heat is really about. even the M4 HG's get a little to warm for my liking on a nice summer day after 3 or 4 mags of rapid fire. of course for you northern guys, a little extra heat is great most of the time. keeps your hands from turing into ice sicles.

ice sicles?


J/K

I have a 20"  bushmaster HBAR barrel cut down to 16"(dissipated)......I think such a heavy barrel for a carbine and a free floating handguard(which it doesn't have right now) may put it on par with a rifle as far as accuracy



"Is a longer barrel more accurate than a short one?

 No! Barrel length has nothing to do with the ability to shoot tight groups and may give LESS measurable accuracy. A longer barrel MAY give a higher velocity = flatter shooting and more energy. A longer barrel, particularly a thin, long barrel will have more vibration upon ignition and a poor quality long barrel has more chance of internal defects in its greater length. Stick with a mid length medium - heavy weight quality barrel for best accuracy. "

phoenix armory

Quoted: another big bonus of the FF rail is they don't get nearly as hot after a few quick mag dumps. living in the arizona desert you find out what heat is really about. even the M4 HG's get a little to warm for my liking on a nice summer day after 3 or 4 mags of rapid fire. of course for you northern guys, a little extra heat is great most of the time. keeps your hands from turing into ice sicles.

I like shooting in the cold because my barrel doesn't heat up as fast.  You can shoot more!!!!!

So, basically, there isn't any reason not to besides price.  It's just as durable.  I would think so, because you see them being used by people that know what danger is.

I am not on the FF bandwagon I once was.  

For specific applications... absolutely.  Special purpose rifles, with quality barrels that you will shoot high quality ammo through?  You bet.

Chrome lined fighting carbines?  I think a good quality non-floating rail (knights) is a solid choice.  Much better than a low end FF tube.... that is for sure.   For the whole FF or not to FF argument.... most people:

1.  Cant shoot better than the difference in accuracy.
2.  Wont shoot ammo that is any better than 2MOA.
3.  Use barrels that while capable, are far from match grade.

FF tubes on carbines really have their place if you are not going to use a standard *pinned* FSB, or you want the tube to extend past the FSB.  Then, without question, yes, you should FF with a SOLID tube.

If I did FF a carbine again... it would be with a LaRue.  Until I see something better, ANY FF I put on my guns will be LaRue.  Mark is a great guy and makes great products.

The prices are close enough. If you're on a budget, I'd get the two piece free floating MI's. I'd also consider them for rifles with permanently attached muzzle devices.

In all other scenarios, I'd go with Larue.

Quoted: So, basically, there isn't any reason not to besides price.  It's just as durable.  I would think so, because you see them being used by people that know what danger is.

Durability is not an issue for a *quality* tube.  Cheap FF tubes can spin on you if they dont have a solid locking device.  I like steel barrel nuts too....

I picked up a ff tube today for 65 bucks. Dont know the manufacturer or model, it is a simply tube of metal, aluminum im assuming. We will see how it does

edit: its a YHM FF tube

Quoted: Quoted: So, basically, there isn't any reason not to besides price.  It's just as durable.  I would think so, because you see them being used by people that know what danger is. Durability is not an issue for a *quality* tube.  Cheap FF tubes can spin on you if they dont have a solid locking device.  I like steel barrel nuts too....

AAAH, thanks everyone.  I think my main mission for my new carbine is going to be 200 yards and under, so I don't know if it's necessary.  Although, I might wan't to mount an eotech way out there so, it might be the way to go.

I might have to start another thread but, I wonder if it's ok to mount an optic to a NON free flot rail?  Or I should say does it work well. Anybody?

Quoted: Quoted: another big bonus of the FF rail is they don't get nearly as hot after a few quick mag dumps. living in the arizona desert you find out what heat is really about. even the M4 HG's get a little to warm for my liking on a nice summer day after 3 or 4 mags of rapid fire. of course for you northern guys, a little extra heat is great most of the time. keeps your hands from turing into ice sicles. I like shooting in the cold because my barrel doesn't heat up as fast.  You can shoot more!!!!!

i love shooting in the colder weather too, unfortunately the summer is quite long in the sonoran desert. we all do what we can to maximize cooling in those months and FF tubes from the big names like KAC, DD, larue, etc all work very well for venting the barrel.

Quoted: Quoted: Quoted: So, basically, there isn't any reason not to besides price.  It's just as durable.  I would think so, because you see them being used by people that know what danger is. Durability is not an issue for a *quality* tube.  Cheap FF tubes can spin on you if they dont have a solid locking device.  I like steel barrel nuts too.... AAAH, thanks everyone.  I think my main mission for my new carbine is going to be 200 yards and under, so I don't know if it's necessary.  Although, I might wan't to mount an eotech way out there so, it might be the way to go. I might have to start another thread but, I wonder if it's ok to mount an optic to a NON free flot rail?  Or I should say does it work well. Anybody?

No. You'll have a wandering zero.

I say Free Float

Here's my rifle - very simlar to what you described.  
LMT M4, LaRue 7.0 Free float and M4 16" barrel.



And here are the results.  100yds, 5 shot group, Federal Redbox .223 55gr


I say Free Float.  

If you get one of the thus aluminum tube-type handguards they will heat up very quickly, I wouldn't do the free-floating unless it is abosolutely necessary.

Quoted: I say Free Float Here's my rifle - very simlar to what you described.   LMT M4, LaRue 7.0 Free float and M4 16" barrel. img281.imageshack.us/img281/2791/dscn12088dq.th.jpg And here are the results.  100yds, 5 shot group, Federal Redbox .223 55gr img329.imageshack.us/img329/7306/dscn12235cq.th.jpg I say Free Float.

Very, very  nice.  Does yours have a govt profile under there or HBAR?

Quoted: Quoted: Quoted:I've heard it said for a fighting weapon, non free floating is better.   I disagree.  Free floating has no disadvantages except a little bit more weight up front. A free floated barrel is harder to take apart.

using a Larue gas block makes it trivial to take the upper completely apart.  the FF rail slides right over the Larue block.  you can take the upper completely apart in 3 minutes, or change the FF rail to a different size, etc.  

see:
ar15.com/forums/topic.html?b=3&f=12&t=231558

and also for you members, more close up on the Larue block:
archive.ar15.com/forums/topic.html?b=3&f=12&t=216958

ar-jedi

Quoted: Ok, there have been alot of opinions posted, but I think it is time to hit the actual purpose of the free-float tube, and who needs one. First, if you shoot ONLY with iron sights, with an adjustable rear sight and a standard military front sight arrangement, you will not get any terrible "wandering in accuracy" with that gun. The reason is that when the barrel is connected to the handguards(non-free-floated), any pressure that is on the handguards and may move the barrel, will ALSO move the front sight along with it, because the front sight is mounted onto the barrel. The problems arise, when you start to use a receiver-mounted optic, and have a non-free-floated barrel. This is because the optic remains stable on the receiver, but the barrel gets flexed by any pressure placed on it by hand-holds, sling tension, bipod pressure, etc. Then the point of impact is suddenly wandering around because the sight plane is "disconnected" from the barrel. So then, you must take the step to free-float the barrel, because it must remain un-moved during shooting, in order to remain "zeroed" with the optic. That is the main reason for free-floating a barrel in an AR15. Of course, non-free-floated open sighted guns can still have a little wandering of POI because the sight radius is different than the "flex-radius" of the barrel, so it will not be a perfect POI for target shooting, but should be sufficient for basic combat. If you want to use an optic, then free-float the barrel.

I don't think it'd be any different in change of POI if you're using your irons or an optic on the reciever with a non free floated barrel.  In either case the barrel will move when exerting pressure on it from a sling or rest or whatever.

That does bring me to another point though.  If you did mount your optic on a NON free floated rail system, wouldn't the zero follow the barrel change / movement?

Quoted: Quoted: Quoted: So, basically, there isn't any reason not to besides price.  It's just as durable.  I would think so, because you see them being used by people that know what danger is. Durability is not an issue for a *quality* tube.  Cheap FF tubes can spin on you if they dont have a solid locking device.  I like steel barrel nuts too.... AAAH, thanks everyone.  I think my main mission for my new carbine is going to be 200 yards and under, so I don't know if it's necessary.  Although, I might wan't to mount an eotech way out there so, it might be the way to go. I might have to start another thread but, I wonder if it's ok to mount an optic to a NON free flot rail?  Or I should say does it work well. Anybody?

Just as an aside, I put a barrel mounted Surefire light on my M4forgery way back when, before rails were popular. Clamped on the barrel. You can remove the light; the mount stays clamped on the barrel.

Just out of curiousity, I tested how the zero changed with the light attached vs take it off. I zeroed the gun with the light off; with the light on, point of impact was unchanged at 100 yards; at 200 it might have been an inch or two low; hard to tell considering I was using XM193 ammo. Certainly it was useable. I'd normally leave the light on, for home defense useage. If I was carrying it in the field, I'd remove the light, attaching it only at night/or when entering buildings. But I'm not a soldier...

This was with an Aimpoint Comp ML2, receiver mounted. Given that I don't use a forend mounted vertical grip, or need to mount more than 1 light, I can't justify the expense and added weight of a floating handguard. Your needs may vary of course.

Quoted: If you use a receiver-mounted optic, there will be change in POI, unless you are different than virtually everyone else. The barrel will flex at the juncture where it is held to the receiver by the barrel nut, when pressure is applied to the fore-end via some hand-holds, sling tension, or bipod pressure. This is a known phenomenon, and is the reason that free-float tubes were invented. I'm not making this up.

I probably didn't make it clear but you missed my point.  I KNOW that the  barrel will move, if you reread my post I said it "will" move but I don't see how there's a difference between using your Irons or using an optic mounted on the reciever.  Either way, the barrel moves with pressure, changing POI.  I know this, I have a standard A2 now.  

What I said was if the optic is mounted on a non free floated rail, possibly the rails will move with the barrel, along with the optic.  I would think they would move in the same direction.  Meaning your optic would follow the barrel.  Now that may be wrong, because there may be binding or something.  You understand me?

Quoted: Yes, All I'm saying is that with iron sights, when the front sight is mounted on the barrel, the sight moves with the barrel movement, so POI is not significantly changed in that circumstance, even if the barrel is moved with pressure. The front sight moving with the barrel compensates for the problem to a large degree. Your aiming point on the front sight moves with the barrel, even if it is flexed. When the receiver-mounted optic is employed, it does not move at all when the barrel is flexed under handguard pressure, so the zero of the optic will not be coincident with the point of impact under those circustances. It is a matter of the barrel moving, and the optic remaining stationary that causes this problem. When the barrel is isolated in a free float tube, all/most the handguard pressure is taken up in the free float tube, and the barrel remains stationary, and should remain coincident with the zero in the receiver-mounted optic during shooting. In your example of the handguard-rail mounted optic, yes it will move with the barrel under pressure and should retain approximately the same zero because of this. However, you need to be sure that the rail on the non-freefloat handguard is sturdy and doesn't have its own built-in flexibility that might cause a problem.

OK, I got you now.  I was the one not fully understanding.  Yes what you say makes sense.  Thank you and I apologize if I seemed a little knobish about it.  Sorry about that.

On a further note, does anyone make a good non free floating rail for a carbine that is sturdy like you say?

Also, is the RRA DEA govt rail a free floated one, does anybody know?

Sling up with an A1 and watch your POI change by a few inches at 100 yards.  small change on small triangle = change on larger triangle.

Quoted: Sling up with an A1 and watch your POI change by a few inches at 100 yards.  small change on small triangle = change on larger triangle.

One time I was shooting my A2 colt prone but I was using an ammo box for support.  And I was putting pressure on the rifle to get it real still.  It changed my POI about 2-3" at 50 yards.

Free floated handguards were really a byproduct of the CMP service rifle crowd as a way to overcome the POI when using slings that when torqued on would put stress on the Barrel. To really understand if you need a free float Handguard, you really have to understand your needs and what you really want to use your rifle for. My my 16" HBAR I run a KAC RAS. it's what I am familar with, allows mounting a a light and a VFG and is very solid.  The pic shows a 5 shot group (Head) shot on my belly at 50 yds (Using my magazine as a Monpod) with a 4MOA Aimpoint and XM193 Ammo

I use my Carbine for Home defense and training. I know what it will do inside a 300 meter circle with NATO Spec ammo. For me freefloating is not a requirement as I would not see little if any difference. if I was shooting Match grade ammo I might be able to tighten that group up, but I don't shoot match ammo. I really thing Freefloat handguards are a waste on this type of Carbine. I would never spent the money unless I was building one from the ground up, and then only if it were a good deal.  Now building a SPR/DRM type weapon that is going to have a magnified Optic and most likely using match ammo... I would want a free float.

You already described your use: Home defense/Hunting and Target shooting. No task you mentioned requires a Freefloat, and chances are you will shoot pretty standard Ammo (nothing fancy, no reloads,etc)

Too many shooters fool themselves into thinking they will shoot better with tighter groups if they have a free floated barrel, when truth is,  most  will likely  never be able to shooter better then what your weapon is capable of.   And the other half will put a Free float on and shoot nothing but Wolf or Olympic.... which canceled out any slight accuracy gains you would have gotten from the free float in the first place.

A good Surfire M73 rail can be had a a very resaonable cost and can be mounted by the average shooter. I'm not a tinkerer. I don't like to take of barrels  Front sights,etc and have all the tools, etc. to mess with my rifles. I like to shoot them. I like to load magazines and go to the range and work on the one variable that needs constant practice and attention, My marksmenship skill.