Why Free Float a Carbine Rail System?

[markm]

Now don't get hostile folks!

I'm just curious why there are so many Free Floated Carbine Rail systems available. To me a FF is what you want on a precision gun or an SPR or whatever. Why go to the trouble and expense of a FF on a CQB/Mid range weapon?

They're generally more expensive and harder to install.

[SHIVAN]

1) Better for the "gangsta" grip, front grips.
2) Good for ease of light mounting.
3) Barrel seems to cool faster.
4) Looks better on my guns.

[mmike87]

Correct me if I am wrong ... and I may be ... but all the top quality rails are pretty expensive, and I think most of the top quality rails are FF. The one's that are not (SureFire?) are expensive anyway.

So why not free float the barrel if you are putting a rail on?

That said I wouldn't put a rail on JUST to free float the barrel, either. But if you're in need of a rail, why not free float?

[KevinB]

Additonally longer bolt life and increased reliability.

*According to a telecon I had with Gus Taylor

[markm]

Correct me if I am wrong ... and I may be ... but all the top quality rails are pretty expensive, and I think most of the top quality rails are FF.

To me the KAC RAS is at least one of the Top Dogs, and it's not FF.

So why not free float the barrel if you are putting a rail on?

All things equal, I agree. But if you have to take off the FSB (with most FF you have to) then all things are not equal.

[markm]

Additonally longer bolt life and increased reliability.

I'm going to have to digest that one for a while.

[KevinB]

I'm out the door for a mission - but I will add to it when I'm back.

[markm]

I'm out the door for a mission - but I will add to it when I'm back.

Be careful!

[Robb Jensen]

Additonally longer bolt life and increased reliability.

*According to a telecon I had with Gus Taylor

I'm going to have to digest that one for a while.

Here's the geek-speak.......most FF rails feature a different bbl nut (not steel) which works like a heat-sink which allows the bolt area of the upper receiver, bbl extension, chamber and thus the bolt as well to cool more quickly. It's been proven that adding rails like the LaRue and DD M4 type rails with non-steel bbl nuts have lower levels of 'cookoffs' when run hard and hot.

As the barrel heats up from firing parts like handguards, handguard caps, delta ring etc all expand and contract and different rates, the way you're holding onto those handguards will influence whats going on with the barrel. On a free floated barrel nothing but the gas tube is in constant contact with it and thus no influence from outside forces.

Ideally all ARs no matter the barrel length should be free floated for consistent accuracy (nothing messing with the harmonics of the barrel). Imagine someone like Joe Satriani playing his guitar which sounds great and then you go over and hold down some of the strings while he's playing, it's probably not going to work nor sound very good at all.

[rob_s]

All things equal, I agree. But if you have to take off the FSB (with most FF you have to) then all things are not equal.

I think that's relative. With the right tools, removing the FSB is a non-issue. Even without the right tools, it varies from minor annoyance to just paying someone else to do it.

The first DD rail I bought I got from ADCO. I just sent them my upper and back it came with the FSB shaved and the rail installed. Pretty damn painless!

I also just plain find the free-floats like the DD and LT to be more secure and stable. I've owned a RAS (or was it a RIS?) and didn't care for the attachment method. Do I NEED a FF rail and the better attachment method? Probably not. But either with a minor investment of time or cash it's worth it to me.