Free Float vs 2-piece

[chiefcrash]

Ok ladies and gentlemen, here's my question to you:

I need a 4 rail handguard so i may attach all sorts of crazy tacticool stuff on my AR. Obviously, there's a lot of choices out there. I'm wondering what reasons are out there for getting a free float handguard (like this) over a 2-piece handguard (like this).

And, just to add to my indecision, I want to put on a flip up rear sight (probably something like this or a railed gas block and picatinny flip-up FS).

so here's my delema: the 2-piece handguards seem like a HELL of a lot easier to install. They're also cheaper. But since i'm probably gonna have to remove the front sight tower ANYWAY to put on any sort of flip up front sight, it seems like I might as well go for the free float. But then I'm worried that my bushie carbon fiber upper might not like handling the torque involved of removing and reinstalling a barrel (has anyone done this with a carbon-15?).

so let me hear your suggestions. Is there any performance advantages of a free float over a 2-piece? Anything i'm not considering? grapefruit?

[TonyM]

If you mount an optic on the rail, with the 2 piece unit it can and will move, making it less likely to keep zero. The 1 piece FF rails won't move on you.

I like the DD rails myself.

[maxicon]

A lot depends on how permanent you want it to be.

There are generally 2 versions of FF rail - 2 piece that require cutting off the delta ring and clamping to the barrel nut, and 1 piece that require their own barrel nut and need the barrel removed. The 1 piece require 'smithing work to change, while a 2 piece can be changed to another 2 piece with a similar mounting style easily.

Non-FF are the most flexible - you can experiment with different styles and go back to a standard handguard if you want. Some lock up very tight, and some have more wiggle to them.

For my next build, I'm starting with a non-FF, because I'm a tinkerer, and want flexibility. Eventually, I may decide on a FF, but until then, I can set it up any way I want, including going back to the basic M4 config.

[proraptor]

If you want the best of both world buy a midwest industries, samson, or troy rail then all you have to do is cut off the delta rig (dremel works good) and clamp the sucker on...I love my midwest rail..

[Paratus et Vigilans]

Ask Bushmaster!

Before you go buying stuff to hang on a Carbon 15, you might want to give the folks at Bushmaster a call and ask them specifically what they think about what you want to do. I was looking at putting a 24" barrel and a free floating tubular handguard on one of my Carbon-15 uppers, and spoke to them about it before moving forward with the idea. I'm glad I did. They told me that there's an aspect to the Carbon-15 upper that makes is suitable only for certain barrels and certain setups, and that wasn't one of them.

Better safe than sorry. Give them a call. They're really good about giving out information and they know their products.

If you've got a 16" barrel on it now, you might as well go with the easier to install two-piece Midwest rail anyway, because free floating a 16" barrel is probably not worth it for better long distance accuracy since that's not a long range barrel to begin with. I've got that same YHM flip up front sight/gas block on my Stag 20"SPR build, and to tell you the truth, it's got a little more play in it than I like. Unless you're really bugged by your existing front sight tower or it's too distracting when you're looking through whatever optics you've got or are going to put on the flattop of your receiver, I'd leave well enough alone. In the alternative, I'd consider a longer rail over a low profile gas block and a rail mounted front sight, flip up or otherwise.

Just my $0.02 worth! Bottom line, build it the way you want it - it's your toy, not ours!

Good luck with whatever direction you wind up going with your build.

[SDlocal]

Don't be scared

I am building my first AR and taking the barrel off and affixing free float uppers is not hard if you have a vice and action block for your upper. I am going to do it there are great instructions at AR15.com

[mltrading]

Go FF, I'd say. You will get better accuracy and the FF forearms are all excellent solid like a rock.

[chiefcrash]

here's an FYI for you guys:

Hello,
We do not use the AR aluminum receiver torque values of 30 to 80 ft lbs when installing barrel nuts on the Carbine 15 receivers. The torque should be on the lower side of about 30 ft lbs. We turn the barrel nut on with an Armorer's wrench by hand without a torque wrench until it is tight then advance it two to three notches for gas tube alignment. If too much torque is applied the treads could strip.
Thank you,

Jim Eden
Technical Support
Bushmaster Firearms International, LLC
Office: 1-800-883-6229 ext. 277
Fax: 207-892-8068

well, that's one question answered...

[chiefcrash]

well, i think i'm gonna go with a free floater. In fact, i think i'll go with the Daniel Defense ones. So here's a really odd ball question hopefully someone can answer:

will one of these work with one of these?

It looks like the front sight folds rearward (away from the muzzle), and i just kinda wanna make sure that it can fold up and down without hitting the tube (can't really tell without better pictures). From the looks of it, the sight will fold to pretty much the length of the gas block, and if the rail doesn't cover the gas block i'm golden. Anybody out there have one of these flip-up front sights/gas block combo? any problems i should be aware of? riboflavin?

[Prc329]

I had a similar setup using a YHM carbine length forearm with that very gas block. The YHM forearm is 7.2 inches

[Paratus et Vigilans]

well, i think i'm gonna go with a free floater. In fact, i think i'll go with the Daniel Defense ones. So here's a really odd ball question hopefully someone can answer:

will one of these work with one of these?

It looks like the front sight folds rearward (away from the muzzle), and i just kinda wanna make sure that it can fold up and down without hitting the tube (can't really tell without better pictures). From the looks of it, the sight will fold to pretty much the length of the gas block, and if the rail doesn't cover the gas block i'm golden. Anybody out there have one of these flip-up front sights/gas block combo? any problems i should be aware of? riboflavin?

That's what I've got on my Stag SPR build, as mentioned earlier: Daniel Defense FF Rail w/YHM flip up front sight/gas block. Yes, the front sight folds rearward, and does not extend beyond the footprint of the gas block. No, it won't interfere with the rail. Mind you, mine is the 12" rail on the 20" barrel, but the shorter rail you're looking at is designed to work with the 16" barrel, so you should have no problems. My only issue is with the relative looseness in the YHM front sight when it's in the up position. Just a hair more looseness than I would prefer, but probably not enough to make any kind of difference in POI out to, say, 300 yards, if you're going for a battlefield zero/center of mass aiming point.

[Prc329]

It might be a quality issue or you just got a loose one or I got lucky. Mine did not seem that loose. It worked fine at 100 yards. Not sure about further. i don't own the upper any longer or I would test it for you.

[Paratus et Vigilans]

It might be a quality issue or you just got a loose one or I got lucky. Mine did not seem that loose. It worked fine at 100 yards. Not sure about further. i don't own the upper any longer or I would test it for you.

Could be QA, though it seems like a design issue to me. It's good and tight side to side. But in the locked-up position, it's got a little wiggle fore-and-aft. And I DO mean little - really just a smidge of movement - but if you aren't paying attention and don't have it pushed all the way forward where it is most upright, it might make a difference of, say, a half click of elevation on the front sight post. So, unless you're using it to go for the X ring at long range, it's not going to mean anything to your accuracy.

I know, I'm just being picky, but if you're into really tight tolerances, you'd want to know about this. Maybe.