Rail mounted front iron sight on a free-float?

[rogerjames]

I've been looking at and researching ARs on and off for a while and am nearing the point of narrowing my options for purchasing my first, and maybe only AR. I'm kind of leaning towards a mid/lightweight set-up and some of these are configured with a low profile gas block covered by a free-float rail.

Although I plan to eventually add an aimpoint or similar optic in the future, I definitely want to start with irons. I seem to remember reading somewhere that a rail-mounted front sight on a free-float hand guard could be problematic under certain circumstances (such as using a sling around the front arm for stabilization), because the flex in the hand guard could obviously distort the alignment of the front sight.

Is this true? If so, what are the alternatives?

 

[Laphroaig]

The purpose of a free floated AR is that sling tension will stress the handguard, not the barrel. Most competition AR's have the front sight on the barrel and therefore will not be affected by tight slings that highpower competitors often use.

To answer your question, will you ever shoot your rifle with a tight, and I mean tight, leather sling? The fact that you eventually plan on installing an aimpoint tells me this isn't a NRA or CMP competition rifle. In that case a sling probably won't be a necessity and shouldn't affect a handguard mounted sight.

The alternative is barrel mounted front sight.

Laphroaig

 

[MrCleanOK]

Alternatives: don't crank down on your sling hard enough to flex the handguard, attach your sling to the receiver end of the handguard, use a free float tube and a pinned front sight base, don't sweat the small stuff.

I vote for the last option. If this was a high power competition rifle you'd be setting it up differently and probably wouldn't be here asking this question. That leads me to believe that this rifle is either just for fun, or for self defence. If it's just for fun, go shoot it and learn for yourself how much pressure it takes on the sling to affect your point of impact. Or, if you're defending yourself from so far away that sling pressure on a free float tube matters, you aren't defending yourself (at least not by contemporary US legal standards).

Build what makes you happy.

 

[rogerjames]

Thanks, that's what I needed to know. Much appreciated.

Yeah, I won't be doing any precision competitions, maybe some local steel matches for fun, but will mostly be used for recreation and potentially for defense.

 

[itsa pain]

I have noticed if you mount a site on the gas block you have get a low profile site. You will have the rear site cranked way up and still be high at 100 yds