Magpul MBUS PRO Zero

As previously posted, got a second set of MBUS PROs set up on one of my ARs. I took it to a local indoor range a couple of days ago to get a quick 25yd zero set up, though a 33m (36yd) / 300m zero is my preference for all my BUIS on my 223/556 platforms. I had to make-do with the range's limitations, but better to have something set than nothing.

Please note that the directions on the ALCO target have no relevance as the MAGPUL PROs have their own system for adjustment. I simply used the target out of habit and I had one readily available.  

Zeroing was non-eventful, which is a good thing in my book. I did under-adjust though, as you can see the slow but steady path leading right to left, down to up. After my first group, I did 4 clicks on the elevation and 4 on the windage, 8 clicks would have been better. Once I punched a few into the center silhouette, I moved over to the 1" square target (from my home printer) for confirmation. Shots still a little to the right, but definitely GTG.

[Click on images to enlarge]

Besides zeroing the PROs, I also brought out my M&P15/22 and tried out some CCI Quiet-22 cartridges to figure what type of drop I would get when compared to the other the CCI cartridges I typically use. 

To put a wrench in the works or, rather, the comparison test, I had also just removed a barrel shroud (you know, the shoulder thingie that goes up) and replaced it with an A2 flash hider. The firearm had a 25yd zero with the barrel shroud, so it was interesting to see the difference of POA/POI with it removed. My 1st groups were all very low (with the CCI Quiet falling off the bottom of the paper) and I adjusted my elevation accordingly, therefore, the 3rd round of groups gives a better picture of what to expect. 

All shooting was done with the M&P 15/22s stock iron sights, no optics.

For reference, the squares are 1" and the paper is 11"x17"

Red = 1st Group 

Blue = 2nd Group

Green = 3rd Group *Look at this one* 

I used CCI Standard Velocity, CCI 36gr HP Minimags, and the CCI QUIET-22. 

Following is the same target but cleaned up with Photoshop to show only the 3rd round of groups for the comparison.

The CCI Quiet is a subsonic round and the M&P 15/22 is a semiautomatic 22lr/rimfire platform. The cartridge does extract and eject, as well as, chamber the following round, but the low energy of the cartridge does not produce enough momentum on the bolt to reset the FCG on my M&P 15/22. So, I have to charge the weapon for each follow-up shot, but when I charge my M&P 15/22, I end up ejecting the round that has just been chambered. It's annoying and your results may vary, but the cartridge definitely has reduced noise, no doubt about that. You can easily shoot without hearing pro (though I would never recommend that) if outdoors.

Final notes. Have fun shooting!