Ok, I recently bought a used KAC 600m sight for a RECCE upper I have.  I dont have any experience with this sight, and I wanted to try it out.

I would like some user information about this sight, and I have a few questions.

First off, is this sight better suited for a .308?  I would like to hear from people who use the sight on 223s and .308s, and how it functions on both.

My other question is how to sight it in.  It was used, so it came with no instructions--I'm not sure if they ever came with any though...  

When this sight is all dialed in, what adjustments need to be made for targets under 200m?  I would assume it would be on the lowest elevation setting, but will targets at say, 100m still be zeroed in?  I guess it throws me that this sight is refered to as a sight for targets 300-600m.  What if you have a target at say 50m unexpectedly?  Do you just adjust your sight picture somehow?  

I know I am missing some fundamental knowledge about the different sight apertures here, so could someone please clue me in.

Thanks.

AFAIK, the sight was designed to work with just 5.56mm.

There's a 'z' mark on the sight for zeroing at 25m/300m.

Crank it to the lowest mark for anything under 200m, not enough difference in POI to worry about 50m and 100m.

Yea, I noticed the "z" mark.  So, what setting is the sight usually left on when folded, "2" or the "z"?

I usually keep it all the way down since most shooting is done under 200m, but it doesn't really matter what you keep it at.

By "all the way down", you mean on 2?

I set mine to '2' and zero at 50y.  That handles anything out to 300M.  For 300M and beyond I can adjust the elevation to the appropriate range.

Quoted: By "all the way down", you mean on 2?

Correct

Alright, that clears things up.  

Thanks.

I have another request...

I know this request requires some work, but I would greatly appreciate it.  Both my 300m and 600m KAC sights came with no paperwork.  I bought both used.

Could someone type up basic, step-by-step instructions on how to sight in either or both of these BUISs.  Step 1, Step 2, Step 3 would be perfect.  Then how to adjust to different distances onces the sight is dialed in.

I have the 300m on a 14.5" with perm Phantom, LMT upper with standard front sight and a RAS II.  The 600m is on a 16" SS WOA bbl, LMT upper and mid-length FF RAS.  I guess I like KAC...

I really want to learn these irons inside and out.  I am looking to take both to the range next weekend with about 2 hours and 100 rds, and I want to get them both sighted in, and then learn the ins and outs of both.  I'm discovering the joy of slow timed shots and learning the weapon as opposed to just always plinking blindly.  

I started out my shooting career after I got out of the Navy, but I have never really taken the time to learn to shoot correctly.  I have always been more of a collector; why buy practice ammo when you could buy yet another rifle...  

But, I would like to remedy that discrepancy, and I want to start with these 2 iron sight setups.  I am also looking into classes.  I'll save the EoTechs and Aimpoints for later.

Thanks in advance.

I don't have the instructions for the KAC 300m but you can use whatever zero you feel appropriate but zeroing the sight at 50 yards to give a 200 meter zero is probably the most popular.

For the KAC 600m, below are scans of the instructions included with the sight, I just got mine today thanks to a fellow AR15.com member.

Quoted: I don't have the instructions for the KAC 300m but you can use whatever zero you feel appropriate but zeroing the sight at 25 yards to give a 200 meter zero is probably the most popular.

I'd love to know how you zero at 25y to get a 200M zero...

Quoted: I'd love to know how you zero at 25y to get a 200M zero...

Sorry, 50 yards, I was going to describe the 25 meter zeroing, but since nobody does it, why bother.

Quoted: Quoted: I'd love to know how you zero at 25y to get a 200M zero... Sorry, 50 yards, I was going to describe the 25 meter zeroing, but since nobody does it, why bother.

I do it

Thanks for the info.

Quoted: Ok, I recently bought a used KAC 600m sight for a RECCE upper I have.  I dont have any experience with this sight, and I wanted to try it out. I would like some user information about this sight, and I have a few questions. First off, is this sight better suited for a .308?  I would like to hear from people who use the sight on 223s and .308s, and how it functions on both. My other question is how to sight it in.  It was used, so it came with no instructions--I'm not sure if they ever came with any though...   When this sight is all dialed in, what adjustments need to be made for targets under 200m?  I would assume it would be on the lowest elevation setting, but will targets at say, 100m still be zeroed in?  I guess it throws me that this sight is refered to as a sight for targets 300-600m.  What if you have a target at say 50m unexpectedly?  Do you just adjust your sight picture somehow?   I know I am missing some fundamental knowledge about the different sight apertures here, so could someone please clue me in. Thanks.

This sight was designed to meet an Army requirement for a BUIS that would work with both 14.4" and 20" barrels in 5.56mm (M855).  A such, we tried to match the clicks from the removable carrying handle, but moved a few numbers to reach a better (more correct) compromise betweeen two diferent velocities/trajectories.  However, as range increases, so does the sighting (dope changes) between individuals for any given range due to human differences.  So when you consider how much one click moves you at say 400 meters, don't be surprised if your 400M dope is one click above or below the "4" marked on the sight, while the shooter next to you is right on the "4.".  
Fortunately, M855 and many 7.62 rounds share the same trajectory to 600M to within this + or - one click.  So the sight works for 7.62 as well.  I mean it is the same BUIS on the Navy's Mk 11 and now the Army's SR-M110.
As far as zeroing, refer to my zeroing instructions above for point-of-aim = point-of-impact at 25M.  For shorter range zeros at 25 meters, just think a minute.  If you achieve POA=POI, if you then rotate the range down to the "2."  Then you rounds will stike where (?) in relation to your point-of-aim.
Correct, they will strike lower.  By how much?  Head to the range and try this out, then let us know.  Although you can figure it out from the table in my instructions, I never find that the "math" equals the "results."

Quoted: I don't have the instructions for the KAC 300m but you can use whatever zero you feel appropriate but zeroing the sight at 50 yards to give a 200 meter zero is probably the most popular. For the KAC 600m, below are scans of the instructions included with the sight, I just got mine today thanks to a fellow AR15.com member. www.pbase.com/edwin907/image/50328076/original.jpg www.pbase.com/edwin907/image/50328077/original.jpg

Thank you Edwin.  Always nice to see something I wrote in print.