Monday, June 30, 2014

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!

Sunday, June 8, 2014

Magpul MBUS PRO Set

Just picked up my second set of MBUS PROs from PSA at a great price. The PROs are all steel construction and finished with a ferritic nitrocarburizing (or Melonite) process for extreme resistance to wear and corrosion. On the first set I received, both sights had the same semi-gloss finish, which seems to annoy some tactical ninjas on the interwebz, whereas, on my second set, the front sight had a mixed semi-gloss and matte finish. The rear sight had the uniform semi-gloss finish. I have no idea if this is a QC issue, but with a lifetime warranty, I'm not concerned at all. 

Packaging & presentation is excellent, as always, Magpul being the Apple/MAC of the firearms industry. 

[Click on image to enlarge]

Instructions are simple and concise. 

AS ALWAYS, before installing or working on your firearm, clear said firearm, because complacency leads to ER visits and you, obviously, don't need that. Don't become a statistic. 

The installation requires either a 1/8" hex key or a flat head screw driver. Whoever packaged my sights torqued the hell out of em, though it was probably the loctite that Magpul products come standard with. Either way, I had to muscle the screws fixed onto the clear packaging rails to get the sights off. Again, not like the first set I received. Once off, I installed them onto my firearm. As noted in the instructions, "do not over-tighten."

The MBUS PROs are deployed by moving them into position with your fingers. One does not have to depress any buttons for this action to be accomplished. Once up, they are solid. All four sights (that I own) have zero wiggle. If yours has wiggle, something is wrong. Obviously if you manhandle them they will wiggle, so don't overthink it. 

To disengage and retract the sights, simply push them down in the reverse direction. Some force may be required, but nothing excessive. 

For zeroing, note that no tools are required to adjust your rear sight or the front sight. The rear sight is self explanatory, just rotate the drum to adjust POI. If you need to move your POI to the right, rotate the drum as indicated (arrow indicates the right), if to the left, rotate the opposite direction.

The front sight is the same. To adjust your POI up, rotate based on the direction of the arrow under the 'UP' (pointing from the 'U' to the 'P') inscribed on the back of the front sight. If the muzzle of the firearm is pointing away from you, it'll be to your right, counter-clockwise. If you need to lower your POI, rotate the drum the opposite direction (clockwise).

On my first set I cowitnessed with my Aimpoint PRO and set my sights based on the red dot. When I hit the range to confirm my zero, I was basically dead on for my 36yd zero and did a slight adjustment. For my second setup, I won't have that luxury as I will have to remove my Burris MTAC and then zero. Below is the rifle. I will be removing the YHM sights (which I like a lot) and install the new set of MBUS PROs. Why, well, because my YHM sights are within a millimetre of touching the MTAC and I would like some additional clearance. The following pictures explain why making the transition to the MBUS PROs an obvious choice.

Final notes. None at this point, I just need to go zero this rifle. If I have an issue, which is doubtful, I'll post back, otherwise this verbiage will remain.

Ah, well, I guess I could give some details on the rifle. The lower receiver is a PSA lower with an ALG trigger and the upper is a right-sided LAR GRIZZLY OPS-4 forged upper. The barrel is a YHM 16" with a PWS FSC556 muzzle break. Looks like prices on the LAR GRIZZLY OPS-4 have gone up and you can no longer order direct. The BCG on mine was produced by Young Mfg for LAR GRIZZLY, an excellent BCG.  EDIT: The good folks at LAR GRIZZLY have started a new brand called Crosshill Technologies and I highly recommend checking out their products and supporting their line.