How does .308 do with .223 BUIS's?

[motorwerks]

It just dawned on me that .308 and .223 have different ballistics, seems like much different but I really don't know. Anyhow I just bought a TROY set and was wondering how far off I'm going to be at farther distances.

My other thing is I took a chance on their rear BUIS with the square diopter thingy, I figured if I hate it I can buy a round one from Troy or buy their round one with the Tritium. Anyway then I found this one and its what got me thinking about the first question. There's no way this thing can be right on at 7, 100, and 300 like it would be with .223 (or I think those are the distances)

[edgecrusher]

I just got the troy tritiums to put on my new rifle, and never thought of that

I suppose you have to look at end usage, my mk214  will wear them and it will be used as a battle rifle, really never meant for long range usage. My lare has magpuls, but they are buis to my leupold mk 4

[motorwerks]

Well I'm stuck with BUIS for a while, I just dumped $700.00 in the last 3 or 4 days into the Rifle and I want to get out and shoot it so glass is going to be a couple months out. My local range has a couple gongs that I LOVE to shoot at ones at like 300-ish and the other I think it at 400 meters. So I guess Ill be seeing how these will work.  <dontknow>

[RayGun19]

Any updates?  I'm wondering the same thing.

[edgecrusher]

i put the troys on my pws when i got it, went to the range, didn't adjust anything, and posted the pics on the pws section. 20rds in a 3 1/2 inch group in rapid fire mag dump, not really trying to keep them close so much as being quick back to target and firing away. they worked fine to 100 too, i would say

[98Z5V]

Putting a .223 BUIS on a .308 AR isn't going to harm a thing, nor change a thing.  It'll work just like a straight-up fixed iron sight setup on the .308.  It's up to you to zero them at whatever range/distance you want. 

What wouldn't work is an A2-type rear sight with the elevation adjustment wheel on there - that's specific to the .223/5.56 ammo.  Those "hundreds" on that elevation wheel will not give you the desired range when run on a .308 AR.  Those numbers wouldn't be accurate like they are on an AR-15.

[survivalshop]

The gen. I magpuls have been on my 16" 308 build since I got them & they work just fine .

I like them.

[jfeenin]

On an AR-10 doesn't the front sight have to be taller due to the fact that the flat top rail is higher above the bore than on a 5.56?

[survivalshop]

That could be why DPMS lowered there 308 upper receivers rail height.

You can adj. the front front sight ,because the difference is not very much .

Some make sure they use the "F" marked front sight assembly .

As far as a BUIS is concerned , if using both front & rear , they work as stated above , you just have to sight them in .

Of course if you are using a railed gas block & put a BUIS on it , the rear sight has to be comparable .

[jfeenin]

yeah I should have been more clear.  When not using a quad-rail the rear sight is higher and (per Armalite for my rifle) needs a taller front sight if using the gas block rail.  Of course you can use sites meant for us on a straight rail on the gas block either.  I wasn't thinking when I got my AR-10 and just figured I'd use the iron sights that came on my LMT MRP AR-15 and that didn't work so well at all.