AR sights question

[LloydXmas250]

Just got my upper and I tweaked my detachable carry handle using RIBZ method so now I can sight in my AR at 100, 50/200, 25/300. However they mention that it's good with the small aperture, not the 0-200 aperture. That got me wondering because I thought the different sizes just meant different target acquisition speeds, not different aiming points. So now I'm confused on how they're different and exactly how I'm supposed to aim with these sights. Sorry for the dumb question, I'm just getting into the wonderful world of ARs.

 

[Quentin2]

The RIBZ (or the IBZ) are excellent schemes to quickly adjust the sights for targets closer than 300 meters - just by cranking down the elevation knob a few clicks below 8/3 or 6/3. And as you said you must use the smaller aperture.

The large aperture is used for close in shooting or low light. To use it, put the elevation knob back to 6/3 or 8/3 and flip to the large aperture. Instead of a 300 meter zero you now have a rougher 100-200 zero and can use it much closer in than that. We're not talking great accuracy here but at least you shouldn't be shooting high like you would with the small aperture and 6/3 or 8/3. That's mainly what it's for, to keep you from shooting high. Of course the RIBZ takes care of that (and with more accuracy) by clicking below 6/3 or 8/3 without having to change from the small aperture.

Flip from both apertures and you'll notice that they are at different heights.

 

[LloydXmas250]

I guess my question is this: I have mostly shot iron sights with V notches so I align the front sight with the top of the V. However with this sight you get a circle with a front sight. Where do I put that front sight? Right in the middle I'm guessing but I'm just wanting to know for sure.

 

[Quentin2]

Yes, the tip of the front sight right in the middle of the aperture. And of course lined up on the center of your target. Try this out at different distances and test out Molon's RIBZ!

 

[LloydXmas250]

Thanks for your help. That's the guide I read. Molon's RIBZ. I wonder why they don't just make those settings default considering the environment soldiers find themselves in now. Thanks also for mentioning that the large aperture is at a different height from the small one. Never noticed and that was throwing me off. Thanks again.

 

[kraigwy]

For those of you who want to use this RBSZ system (I dont), here is a link on how to set it up.

http://www.ar15.com/forums/topic.html?b=3&f=18&t=328143

I'm old school, I like the orginal 250 Meter BSZ, both with ARs and Bolt guns.

As taught by the AMU in the Sniper School, The 250 BSZ works to obtain Head Shots to 300 meters. In using this system, its easy to Max the 40 shot 300 meter Record fire qualifications on the pop up targets. One will notice with this zero you are never more then about 4 inches high or 4 inches low to 300 yards, more then adiquate for 3-gun or multi gun matches.

This is with the A1 or SP1 rifles. On my White Oak, service rifle, the rear sight is set up differant then the A2 Sight shown in the above link. It has witness marks more to the liking of High Power shooting, much like the M14/M1A. I have my WOA service rifle where the rear sight is bottomed out at 200. I can do my come ups for 300 & 600 yards, then screw the front sight down four revolutions, using the 600 yard setting, I'm right on at 1000 yards.

My SP1 is differant, you only get the elevation changes by using the front sight, which in 3 gun or multi-gun, you often dont have time. I've found with the 250 yard BSZ, I have no difficulty engaging targets to 400 yards. I only have a 300 yard range in my back yard, and I have gongs from 25 yards to 300 yards. The 250 BSZ works perfect for my shooting situations.

 

[Dave R]

Yes, the tip of the front sight right in the middle of the aperture.

One of the truly cool things about aperture sights is that they work best when you don't TRY to center the front sight. Just let your eye do it naturally.

When you TRY to center the front sight in the aperture you may or may not get it in the same place every time. If you ignore the aperture entirely, and just focus on getting the front sight on the target, youe eye will automatically center, with more consistency than you can if you try.

 

[Quentin2]

Thanks for your help. That's the guide I read. Molon's RIBZ. I wonder why they don't just make those settings default considering the environment soldiers find themselves in now. Thanks also for mentioning that the large aperture is at a different height from the small one. Never noticed and that was throwing me off. Thanks again.

Actually the US Marines have been doing something like this since the M16A2 came out in the 1980s. And Army Col. Chuck Santose has done much to share this information as well calling it the IBZ (Improved Battlesight Zero).
http://www.m4carbine.net/showthread.php?t=7292

Molon' RIBZ refined the IBZ further, adding more clicks below 6/3 - 8/3 to include a 100 yard zero.

I like it because it of all it adds plus it allows you to have the good ol' military BZ (Battlesight Zero), too.

 

[LloydXmas250]

I've adjusted it to the RIBZ already but won't be able to zero it for a bit. When I do zero it though, what setting should I do it on? 100? 50/200? or 25/300? Also, according to the military procedures, they move the wheel in one click to the z mark when zeroing at 25/300. I leave that part out now that I've changed to RIBZ right? I just zero on the 100 setting if that's what I want to zero at correct?

 

[Quentin2]

Well it depends...

With the RIBZ you can zero at 25 meters, 50 yards, 100 yards or 300 meters. Just set the elevation knob to the proper spot.

As far as the standard military BZ for 25/300 meters at 25 meters, you only click the elevation knob to Z when zeroing an M16A4 (20" barrel). For the M4 with the 14.5" barrel you leave it set to 6/3. So if your AR has a 14.5 or 16" barrel don't zero using the Z.

Once you're properly zeroed at 25 meters and assuming you have an A4 flattop you should be able to click down for the IBZ 50yard/200meter zero or all the way to minus 6 for Molon's 100 yard zero.

 

[Quentin2]

I'm going to add a few links that might be helpful:

M4 target PDF:
http://ohmr.ohio.gov/forms/ohmr2444-b.pdf

There is a slight error, it should say 6/3 not 8/3 since most M4s and many M4geries have a removable carry handle.

M16A2 target PDF: (for the M16A4 move to the Z to sight then return to 6/3)
http://www.bobdbob.com/~deneb/doc/targets/m16a2-25m-zero.pdf


And here is the US Army M16 and M4 bullet trajectory tables for the BZ and IBZ.
http://www.usaac.army.mil/amu/ServiceRifle/M16-M4 data.pdf

 

[LloydXmas250]

Thanks for those links. I have an M4 with the detach handle so that one will work. Now after I zero on that at 25, I should in theory just move my elevation knob to 6/3-6 and be zeroed at 100 correct? Also, is that target the right size when I print or does it get changed in size when I print? I thought I read somewhere on one of those kinds of targets that you have to print it a special way. Thanks again Quentin.

 

[Quentin2]

Yes, after a correct BZ at 25 yards 6/3 -6 should give you a pretty good 100 yard zero. Molon and Col. Santose do caution that clicking the elevation knob to a new zero isn't meant to be target grade accuracy but plenty good for most uses.

Oh yeah I forgot... when printing out those targets in Adobe Reader, in the print window set the Page Scaling box to None before printing. The target should fill the page except for small margins.

 

[LloydXmas250]

Mine doesn't open with Adobe. I have a Mac so things are a bit different and there is no size adjustment so I'm guessing it will print at the right size. Would you happen to know what the diameter of the inner circle should be? That way I can check to make sure it's right.

 

[Quentin2]

Mine doesn't open with Adobe. I have a Mac so things are a bit different and there is no size adjustment so I'm guessing it will print at the right size. Would you happen to know what the diameter of the inner circle should be? That way I can check to make sure it's right.

Ah... Well I'm a PC! That diameter is just a skosh less than 1-5/8". For more accuracy (pardon the pun) the large grid is 7-7/8 high x 7-5/8" wide. These measurements were taken from a real military M4 25 meter target printed on thick cardboard stock.

Your printout probably will be slightly small and I suppose if you can't get close to the correct size via software you could use a copier set to 103% or whatever to get it dead on.

 

[LloydXmas250]

Measurements are the same. Thanks again Quentin.

 

[Quentin2]

All right Lloyd, time to go shooting!

 

[LloydXmas250]

I wish. I'm in CA so I'm still in my waiting period for the lower. Then I need to piece it together and then I'll be out the the range. Can't wait. Thanks again