Monday, October 8, 2012

MBUS Shakedown

I was actually able to get out shooting twice in two weeks.  I know, I wouldn't have believed it either.  Last week, I was chomping at the bit to get my SR556 out into the desert for some shooting, and to give these new MBUS sights a shakedown test. 

Originally, my wife and I were going to go to the outdoor range, but after realizing their hours just plain suck, we turned the Jeep south and headed for the hills, literally.  We found a good location to set up shop, so we set a target out 50 yards from the hood of my Jeep, and started to go to work.  My first task was to get the sights on target.  So, I loaded a 5 round magazine and rested the rifle and my hand on the A-pillar of the Jeep's windshield.  Since we originally thought we were going to the range, we left the table and the rifle rest at home.  Oh well, I figured I'd give it a shot over the Jeep's hood anyway.  Maybe I'd get lucky. 

My first group went center high, about 2" above the bullseye.  Fortunately, I remembered my little 10x monocular, so I didn't have to walk out to the target every time to verify my hits.  From my position, I could see a little 1.5" group of 5 sitting over the bullseye at 12 o'clock.  Well, one thing's for sure: the MBUS sights didn't need any windage adjustments, and there wasn't a breath of wind at all outside. 

I fired another group of 5 just to be sure the first wasn't a fluke.  Sure enough, when I looked at the target through my little monocular, I could see that same group with some more tiny holes and one ragged one 2" up from the bullseye at 12 o'clock.  Satisfied that my rifle and me were on the same page, I adjusted the front sight up to lower my point of impact (POI) on the target.

My third group sailed right through the bullseye with a very tight group.  I fired another set of 5 rounds to verify.  As before, the bullseye was now a ragged hole.  Not bad for shooting over the hood of the Jeep.

Zeroing the red dot was even quicker.  After lining the red dot up with the front post of the MBUS sight, I fired a three round group.  Upon seeing the group to the left of the target, I made the proper windage adjustment, referenced the front sight and fired another three round group.  All three rounds went through the bullseye.  I fired one more group to verify with the same results. 

All told that day, I fired 40 rounds out of my AR15.  About 32 shots to verify all zeroes on both the sights and the scope.  The last few remaining rounds, I just took pot shots at the target offhand at 50 yards.  My wife was itching to shoot some pistols, so I put the AR15 away for the day.

Yesterday, Oct 7th, was the fun day for me.  This time, instead of trying to punch tiny holes in paper, I brought my steel 8x8" target and stand.  I initially set the target up 50 yards from my Jeep.  After warming up on my 22 pistol (taking 50 yard shots and hitting the steel), I switched to the AR15.  After loading 20 rounds into the magazine, I flipped the scope caps down and started firing.  Of course, I shot off the red dot sight first because I wanted to make sure it was okay.  Yep, all 20 rounds hit home on the steel, and I could hear the distinct "TUNK" sound they made upon impact.  I flipped up the MBUS sights and took another 20 rounds to the target.  I missed two, but it was due to me rushing the shot and getting careless.  After telling myself to calm down, I shot the rest of the magazine out without a single miss.  Okay, I was bored.

I looked back to see how far away I could get, and noticed a ridge high up above where I was shooting.  I decided to load a couple magazines full and take a short hike away from the target.  After climbing into and out of a shallow ravine, I hiked straight up the hill to a ridge line high above the target.  Prior to leaving, I had walked over to the target and marked it's position with my GPS, as well as it's elevation so I could range it.  Without the convenience of a range finder (next thing on my list), I would need to use some trigonometry to range the target. 

The first ridge looked like a challenging spot to shoot from.  I was already having trouble seeing the target with the naked eye, so I sat down and caught my breath before loading the weapon and taking the first shot.  While waiting for my heart rate to slow down enough (so that the first shots weren't wasted), I calculated my range was about 250 yards.  Not a bad start.  It'd been awhile since I shot guns at that distance, and I've never shot an AR15 that far away.  I decided not to use the MBUS sights because I couldn't see the target when the front post covered it.  Instead, I used the RDS because with a 2 MOA dot, it only appeared about 4" or so over the 8" plate. 

Without a spotter, I thought it would be challenging to see where the bullet hit the dirt if I missed.  I took aim dead center on the target and squeezed the trigger.  I watched the dirt just above the target fling up as the bullet slammed into it.  I knew I needed to aim low.  Fortunately, my sight picture was never lost when I fired, and I was shooting with both eyes open so as to negate the astigmatism in my right eye.

I leveled to red dot just beneath the target, so that it appeared as if it they were stacked on top of each other.  I held my breath, squeezed the trigger, and heard the shot break.  A half second or so later, I heard the distinct "TUNK" of the bullet slamming into the steel.  I waited another couple seconds, squeezed the trigger, and heard the same "TUNK" sound again.  After about 10 rounds, I was satisfied that I could do this all day.  So, I looked up the hill and saw another ridge, this one was almost all the way at the top.  So, I safed the weapon and hiked straight up. 

As I hiked in the loose gravel, dirt, and rocks, I could not help but bang my rifle a couple of times.  It was nothing serious, but it would have been enough to knock a lesser scope and sights out of alignment.  I figured it might be a good idea to shoot the target from 100 yards away with the MBUS sights when I got back down to the ravine. 

I set up shop on the ridge line.  From here, the target was barely visible.  The steel blended into the earth behind it.  The only reference I had was this tire I found and used as an anchor, and the wooden 2x4 that holds the plate 4 feet off the ground.  I calculated my distance, referencing elevation differences, my new coordinates, as well as the angle I was shooting at toward the target.  A squared, plus B squared equals see you later.  The hypotenuse (the distance the bullet would travel) was 425 yards, give or take.  Now mind you, I have only shot this far once in my life with bolt action guns, at a range, resting on a bipod.  I had never done it sitting up on a ridge in the desert, in wind, using only my arms and legs as the rifle support.  So this was a first.  Plus, my visual acuity at that distance isn't so great.  it was damn hard for me to see the tiny plate, which now would be completely covered by the red dot, since it would appear to be over 8" across.

After settling down, I peered through the Aimpoint Comp ML3.  From this distance, I could see the Jeep in my field of view, as it was parked 50 yards away from the target.  I figured that, at this distance, a jerked trigger might leave me stranded, so I paid close attention to everything my body was doing.  After one final check to make sure no one was in the area (I had the microphones on my ear muffs cranked up so high that I could hear a mouse fart from 150 yards away), I reacquired my target.  After a few seconds, I pressed the trigger as slowly and deliberately as I could.  When the shot broke, the ear muffs attenuated it so it didn't blow my ear drums out, but quickly went back to listening to everything around me. I never saw any dirt fling up through the scope, so I assumed I hit a rock.  Then I heard it.  For what seemed like forever, the bullet sailed from the top of the ridge down to the target well on the other side of the narrow valley, and slammed into the steel, making a different, but distinctive "CLUNK" sound.

"Holy crap!" I said as I watched the 2x4 swing back and forth.  I actually hit it, on my first try no less!  I decided to give the backup irons a chance.  I flipped them up and left the red dot running.  I covered the target with the front sight post, and fired.  MISS!  The round sailed right over the top.  I adjusted my aim down a bit and fired again.  Within a short time, but what seemed like an eternity the steel target confirmed a hit with another "CLUNK" sound.  I was pretty sure that the rounds weren't hitting as hard at this distance because the target feedback didn't sound like it had the authority of a 50 yard shot.

I was convinced I was at the limit of what these 55 grain PMC rounds were capable of, and decided that unless I really wanted to watch someone suffer, I wouldn't be taking 400 yard shots with my Ruger SR556 unless I absolutely had to.  That being said, I still wanted to shoot, so I fired another ten rounds with the irons, missing a few, but doing quite well overall.  I was impressed with not only myself for shooting a small target at that distance with irons, but because the irons were so precise.  I had still not adjusted windage at all.  The rears sit dead center.  You have no idea how awesome that makes my brain feel! 

For the last few shots, I used only the RDS and after missing the first one, I corrected my point of aim (POA) and sent the rest home.  I don't know what the time of flight for the bullets were, but it sounded like it took awhile for them to reach the target.  And 223rem moves pretty quickly.

With only 10 rounds left, I hiked back down to the ravine, which I calculated was just under 100 yards away from the target.  I fired the remaining 10 rounds with the irons only, and sent them all home.  I was pretty happy. 

All told, I've got about about 200 rounds fired since putting the new sights on and they haven't come loose at all.  These sights are fantastic.  I must say also, the red dot was impressive at longer ranges, and even with an unmagnified optic, I didn't seem to have a problem shooting that little steel plate despite the fact that it was difficult to see. 

So far, everything about this Ruger SR556, the sights, and the scope have impressed me.  I would bet my life on this gun any day of the week.

-James

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