Are iron sights caliber specific?

[jpkar]

I can't seem to find the answer to this. Can I use any standard iron sights on a 9 mm AR upper, 7.62x39 AR upper or an AR 308?

[CSACANNONEER]

Yes, any sights will work fine.

[jpkar]

Thank you!

[joedi]

Yes, you just zero the sights where you want.

You may find "same-plane" and "A2" options with dual aperture rear sights. If it doesn't say, and it is a dual aperture, I would assume it is A2. The only difference is that a same-plane has the same aiming point for the small and large aperture in the rear sight. An A2 is intended for the small aperture to be zeroed for 300m with 5.56/.223, and the large aperture to be used closer (USMC used to zero the small aperture (300m) at 36yards, and I think the Army did or does 25yards). Also, most rear sights with elevation are made for 5.56/.223. There are some for .308 also. Be careful with the non-pop up rear .308 sights. Some, such as Rock River Arms's stand-alone rear sight (for their LAR8 .308) actually requires a hole in the top of the receiver for the extended elevation screw to go into.

If you are nit-picky, you may want to look for same-plane rears when looking for sights for a different caliber than 5.56/.223. Otherwise, just zero them and use whatever you have.

[jpkar]

I typically use KAC flip up micro front and rear sights
I'm not sure what same plane means

[jpkar]

I don't think the KAC sights that I use have dual apertures
There is only one size hole in the rear

[joedi]

KAC is a good brand. Samson and Troy are too. The KACs have one aperture, so where you zero it is all that matters.

They do have an elevation adjustment on their rears. Just check what caliber it is for, if you care. I think they make a 5.56 and a .308. If you're putting it on a 9mm, you most likely won't care about elevation.

[Carcassonne]

Are iron sights caliber specific?

I can't seem to find the answer to this. Can I use any standard iron sights on a 9 mm AR upper, 7.62x39 AR upper or an AR 308?

Fixed iron sights (like what are on most pistols) are not caliber specific.

Iron sights with variable range adjustments like what you see on almost all battle rifles are not only caliber specific, but also bullet weight and style specific. AR-15, HK, AK-47(74), SKS, M1 Garand, M1 Carbine, Mauser 98, British Enfield, FN-FAL, Springfield 1903, etc all have adjustable rear sights that are calibrated for a specific barrel length, bullet type, weight and velocity. Of course temperature and barometric pressure change the ballistics of a bullet.

I know the front sight posts on the AR rifle are different depending on whether the upper is a carbine-length, mid-length, or rifle length. I am not an expert on AR sights, so I can't give you better info.

For general shooting just buy something you like, and make it work.

[jpkar]

KAC is a good brand. Samson and Troy are too. The KACs have one aperture, so where you zero it is all that matters.

They do have an elevation adjustment on their rears. Just check what caliber it is for, if you care. I think they make a 5.56 and a .308. If you're putting it on a 9mm, you most likely won't care about elevation.

That actually makes perfect sense to me. Its mostly the elevation adjustment that matters.

[jpkar]

Fixed iron sights (like what are on most pistols) are not caliber specific.

Iron sights with variable range adjustments like what you see on almost all battle rifles are not only caliber specific, but also bullet weight and style specific. AR-15, HK, AK-47(74), SKS, M1 Garand, M1 Carbine, Mauser 98, British Enfield, FN-FAL, Springfield 1903, etc all have adjustable rear sights that are calibrated for a specific barrel length, bullet type, weight and velocity. Of course temperature and barometric pressure change the ballistics of a bullet.

I know the front sight posts on the AR rifle are different depending on whether the upper is a carbine-length, mid-length, or rifle length. I am not an expert on AR sights, so I can't give you better info.

For general shooting just buy something you like, and make it work.

That makes sense with regards to caliber but didn't know barrel length affects the sight as well. Now I just gotta figure out what sight I can use on my 7.5" AK47 AR upper, and 8.5" 9mm ar upper

[Munny$hot]

I typically use KAC flip up micro front and rear sights
I'm not sure what same plane means

Troy makes a Micro height sight which is shorter than standard AR flat top height sights. Back in the day when everyone was taking off their front A post sight and replacing them with aftermarket gas blocks there where also front gas block height sights and rail aka standard height sights.

Also KAC does have a flip up with dual apertures which is done using an insert.

[MXRider]

Ssme plane just means both apertures will give the same point of impact. One hole is just smaller than the other. Lots of dual aperture sights give different points of impact between the two. I prefer same plane or single aperture myself.

[OpticsPlanet]

You can use any iron sights with any caliber, but I have found on my AR pistol that I don't like the full height iron sights (just like I don't mount the optic at the standard AR height).

The Troy Micro sights are what I prefer for irons on an AR pistol

-Matt S.