AR handguard length?

[sigstroker]

Is there a rule of thumb for the length needed for an AR free float handguard?

Like if I intend to use an 11.5" barrel, is there a magic number to add or subtract to the barrel length to determine the length of handguard needed?

[D.A.V.I.D.]

1" seems to be the standard

[SigSauerP226]

Think it’s mostly preference. Longer gives you more rail space for accessories if you need them, potentially protects the barrel, gives you more room to rest the gun up against or on things, allows your support hand hand to be further out, puts the front iron sight or bipod further out. Shorter saves a little weight, but I think that’s why we see more full length now, not sure if there is any real benefit to shorter other than weight. Oddly enough I actually like the look of a 12” handguard on a 16” barrel better, but my most recent builder set I went 15” handguard. If you use a linear comp on an 11.5, I think a 12” handguard would be nice with the only the end of the comp sticking out of the handguard.

[tradecraft]

Most people will at minimum want to cover their gas block.

[r1ghtw1ng]

I know for a perfect flush fit of the Surefire warcomp, a Geissele true 13" rail is perfect for a 13.7" barrel.

Likewise, a Geissele 9.5" rail is perfect for a 10.3" barrel. I would say .7-.8" is the sweet spot for a flush fit.

Careful, some rail manufacturers (BCM) say 13" or 15" rails but are off by up to .5".

[Sicarius]

Longer sight radius if you use irons.
Kevin

[bigstick61]

Think it’s mostly preference. Longer gives you more rail space for accessories if you need them, potentially protects the barrel, gives you more room to rest the gun up against or on things, allows your support hand hand to be further out, puts the front iron sight or bipod further out. Shorter saves a little weight, but I think that’s why we see more full length now, not sure if there is any real benefit to shorter other than weight. Oddly enough I actually like the look of a 12” handguard on a 16” barrel better, but my most recent builder set I went 15” handguard. If you use a linear comp on an 11.5, I think a 12” handguard would be nice with the only the end of the comp sticking out of the handguard.

Yeah, it really depends on what you want to do with it. I wanted to be able to use a bayonet, among other things, as well as to cover the gas block completely, which dictated a particular length range for that to work. In the case below, I used a 10.5" handguard with a 16" mid-length barrel. I would say the shorter end should be the minimum that will cover the gas block entirely or butt up against a FSB or equivalent, the maximum the longest that will work the muzzle device and whether or not a suppressor is desired for use.

[BucDan]

The modern look is having the rail as long as possible.

I've always been a fan of the gas block being exposed, ever so slightly, by .5" or 1". I thought it looked good. KAC and LMT did this back in the days, I loved the look.

[sigstroker]

I wanted to know what was considered standard because I'll probably get mine 3 or 4 inches longer so I can telescope a silencer inside the handguard a few inches. So, by your answer I guess I'd be getting a 14 or 15 inch.

[SigSauerP226]

I wanted to know what was considered standard because I'll probably get mine 3 or 4 inches longer so I can telescope a silencer inside the handguard a few inches. So, by your answer I guess I'd be getting a 14 or 15 inch.

That would be a good way to go, to me it looks more slick with a short barrel and larger diameter muzzle device like a suppressor to have a longer handguard. I’d imagine you still want the handguard back a half inch or so at least from the end of whatever barrel/muzzle device. Just check the internal dimensions of handguard, for example Aero’s enhanced is larger than their ATLAS for muzzle device like suppressors even according to their description. To me though, like mentioned above, a flush fit with a suppressor looks good, too. All personal preference.

Also, total irrelevant aside, you on SF too?

[CamW]

Check out this thread from AR15.com

https://www.ar15.com/forums/ar-15/What-Rail-Length-Do-I-Need-A-Guide/12-751983/

[ar15barrels]

Is there a rule of thumb for the length needed for an AR free float handguard?

Like if I intend to use an 11.5" barrel, is there a magic number to add or subtract to the barrel length to determine the length of handguard needed?

Needed for what?
Needed to not extend too far?
Needed to reach the muzzle?
You can use a barrel a few inches shorter than the handguard with a linear comp and let the linear comp sit almost flush with the rail as long as your rail and comp are compatible sizes.

What's your goal?

[ar15barrels]

I wanted to know what was considered standard because I'll probably get mine 3 or 4 inches longer so I can telescope a silencer inside the handguard a few inches. So, by your answer I guess I'd be getting a 14 or 15 inch.

There are only options.
There is no standard unless you are limited by a FSB that's mounted on the barrel and do not have a rail with a window for the FSB.
Then you need to stay behind the FSB so 7" for carbine.

[sigstroker]

That would be a good way to go, to me it looks more slick with a short barrel and larger diameter muzzle device like a suppressor to have a longer handguard. I’d imagine you still want the handguard back a half inch or so at least from the end of whatever barrel/muzzle device. Just check the internal dimensions of handguard, for example Aero’s enhanced is larger than their ATLAS for muzzle device like suppressors even according to their description. To me though, like mentioned above, a flush fit with a suppressor looks good, too. All personal preference.

I would want it to stick out past the handguard by at least a couple inches so I could grab it to unscrew it. I also want about 4 inches of it to be telescoped into the handguard to make it less likely I'd get burned if I'm in a "chaotic" environment and can't pay close attention to the can.

Also, total irrelevant aside, you on SF too?

Don't know what that is.

[trackhazard]

Warsport LVOA comes to mind for really having your handguard maxxed out.