Sighting In Back-Up Iron Sights (BUIS)

[FPrice]

Well, I just got an ARMS flip-up rear sight for my Bushie A3 16" Carbine but am a little uncertain about sighting in and distance adjustments.

I plan on using a Bushmaster sighting-in target and following the instructions for a 25-meter zero. So far no problem. But once I have this accomplished, how does one adjust for distances? Or should I even be concerned about this (especially with a 16" barrel)? The ARMS BUIS does not have the elevation dial that the regular A2 rear sight has. I guess that I sight it in for a 25-meter zero and just go with that.

BTW, this is back-up to an EOTech 552, again for which I do not have any instructions.

Any comments or suggestions?

 

[swatmedic]

I sighted my Bushy in at 50 yards, I use the eotech with a RRA dominator mount/sight. If I remember right if you zero at 25 meters you will approx 1" high at 100, and back on target at 200. I realize that my 16" barrel with non magnified optics is not going to be of much help to me over 100yrds, so I am more concerned with CQB distances.

 

[Big Daddy 45acp]

Depending on what you intend on using the rifle for, SHTF, Zombie attack or mass migration of liberals onto your property, or just plain plinking, I would just dial the sight in for point of aim=point of impact at 25m. This should keep you on target out to around 300m.
Remember, these are back up emergency combat sights. I hope you don't plan on shooting at Camp Perry with them!

As for the Eotech, you can download the manual here:

http://www.eotech-inc.com/documents/511-552_User_Manual.pdf

 

[FPrice]

Thanks for the replies. This is my attempt at putting together a CQB-type carbine. I think I'll stick with the 25-meter zero and work from there. For Camp Perry I still have my Colt HBAR.

As for the Eotech, you can download the manual here:

Thanks for this url, I must have missed it while looking for information on the EOTech.

 

[Jose]

Get a 50 yard zero. With it you will be within 1.5" of line of sight (LOS) all the way to 225 yards. You will be on at 50, up to 1.5" above (LOS) from 50 to 200, on at 200 again, and down about 1" at 225. beyond that it's time for hold over.

A 25 yard zero puts you back on line on LOS at 250 yds, but between those two points your bullet will climb to 3.2" at 150 yds before coming back down. At 300 yards you will be 5.5" low.

Since 99% of a carbine's use and about 100% of the BUIS use will be in close (inside 200 yds), I'd zero for 50/200 yds and shoot center of mass.

That's how my M4gery is set up.

ETA: the trajectories I described assume a 55 grain FMJ boat tail bullet going 3000 fps. That's how most 55 gr plinking ammo is loaded.

 

[second]

Ditto what jose said, although I thought 50 yards corresponded to 300 yards.
Regardless i would go for the 50 yard zero

 

[FPrice]

I took it out today and was able to get the windage set at 25 yds/meters. But the bullet strike is about 2" high. Need to adjust that with the front post sight but didn't have time (was having problems with the windage, all my adjustments seemed to move backwards - ?).

Will try for the 50 yard zero next time. Thanks for all the help.

 

[second]

This might help you out, read it before you hit the range.

http://groups.msn.com/TheMarylandAR15ShootersSite/improvedbattlesightzero.msnw

 

[Cross-X]

Well, I just got an ARMS flip-up rear sight for my Bushie A3 16" Carbine but am a little uncertain about sighting in and distance adjustments...

...BTW, this is back-up to an EOTech 552, again for which I do not have any instructions.

Any comments or suggestions?

No manual, no idea how to actually use it, but I bet you console yourself by thinking that you got a really good deal on EBay.

 

[FPrice]

No manual, no idea how to actually use it, but I bet you console yourself by thinking that you got a really good deal on EBay.

One was from a local dealer (still in the bag) while the other was from a fellow NESer.

I leave EBay to you, counselor.

Objection overruled.