AR Front sight question

[dhoenich]

I picked up my first AR for Christmas... It is a very inexpensive ATI OMNI model. When I was looking, I was somewhat aware of issues getting front blocks with rails and finding sights since this didn't have any. I'll eventually put on some mid grade optics, but would like to put sights on first. This has a front rail that is taller than most I've seen. I thought it was receiver height, but putting straight edge over everything, it looks to be about 1/16" shorter (about the thickness of a quarter). I know most of the front blocks are shorter than that and use a different front sight for a regular height gas block. Would I get a same plane set and hope there is enough adjustment? I know I need iron front sights because of heat. Any recommendations for cheap flip up that will work?

Thanks,
Dennis

[The Annoyed Man]

Does the forend cover the gas block? If not, you could just put a standard A2 combination front sight / gas block on it, and then it won't matter because the sight height will be correct relative to the receiver height. Alternatively, just put a rail system of correct height on the gun, and then mount any kind of front sight you want.

[dhoenich]

I wasn't looking to replace the block or add a rail yet. It looks like it lines up, but is just a hair shorter. Will there be enough adjustment on a rail pair to handle the 16th of an inch difference?

I added a couple pics to show what I think I'm talking about.

[The Annoyed Man]

OK, I see what you mean. You don't have a rail system; you have a basic hand guard, with a gas block that has a short section of rail on it.

My guess is that there are front sights available that have a little extra height in them to make up for the difference. But without a sight that makes up the difference, yes, it will impact your sight alignment. Being a 1/16th of an inch off at the gas block might translate to several inches off at the target. Now, you can raise your front sight post to compensate, but you'll have that much less adjustment available to you for subsequent elevation changes.

OTH, once your sights are dialed for whatever zero you choose (25 yards/meters, 50 yards/meters, 100 yards/meters, whatever), you'll be using your irons strictly as a point blank proposition. "Point blank" meaning, no holdovers or holdunders, you aim for COM, and your shots are guaranteed to hit within a few inches high or low of POA all the way out to say 300 yards.

But if you change your mind, an A2 front sight/gas block is cheap....... less than $20 at Brownells: http://www.brownells.com/rifle-parts/si ... 81261.aspx

[ELB]

Windham arms [Correction: Windham Weaponry] makes a front sight post that is a wee bit longer than the standard ones for front sights mounted on gas blocks. Also there are front sight assemblies specifically made for mounting on gas blocks that are a tetch lower than the rail on the receiver.

[The Annoyed Man]

And don't get a plastic sight eg. most of the Magpuls - they'll melt from the gas-block getting hot.

Good suggestion.

[dhoenich]

I was able to get in touch with ATI today and they said a rail height front sight 'should' have enough adjustment to compensate for the difference with this block. They were willing to sell me one for $70 for the set. I have a metal set by UTG ordered through Amazon and will see what happens... Thanks for the info.