Crosman MK-177 multi-pump pneumatic: Part 3
by Tom Gaylord, a.k.a. B.B. Pelletier
Today, we’ll begin testing the accuracy of the Crosman MK-177 multi-pump pneumatic. Because this rifle shoots both pellets and BBs, I’ll test both, but not at the same time and not in the same way. Today’s test of lead pellets was done at 10 meters, using the iron sights provided with the rifle.
I decided to use 5 pumps per shot for the entire test. That was both easy to do and was also pretty quick. According to the velocity test we did last time, Crosman Premier lites were averaging just over 500 f.p.s. on 5 pumps.
It took five shots to sight in the rifle. The first shot was 3 inches high and 2-1/2 inches to the right. Crosman supplies a sight adjustment tool with the MK-177, and I had to use both ends of it. One end is a flat-bladed screw driver that moved the rear sight to the left. The directions are printed on the sight, so there’s no confusion.
The front sight had to be raised because the rifle was shooting too high, so I unscrewed the front sight post several turns. Shot 2 was about three-eighths of an inch too high and three-eighths of an inch too far to the right. The hole was in the black bull, but it wasn’t centered. So, I made small adjustments to both the front and rear sights and fired again. This shot cut the 9-ring, which was close enough for me. I fired the other 2 shots, and they landed near the third shot. Sight-in was finished.
Crosman Premier lites
This is a Crosman rifle, so the first pellet I chose to test was the Crosman Premier lite. The first pellet hit the 10-ring of the bull, so I stopped looking through the spotting scope and just shot the gun. After the 10th shot, I looked at the target and saw a disappointing horizontal group that measured 1.173 inches between centers. None of the shots had been called as pulls (meaning the sights were off target when the gun fired), so this group surprised me.
Air Arms Falcons
Next to be tried were the Falcons from Air Arms. They’re domed pellets made by JSB and weigh 7.33 grains. Once, again, the first shot cut the 10-ring, and I never looked after that. This time, the group was much better, measuring 0.839 inches between centers. It’s also much rounder than the Premier lite group, leading me to think the rifle likes this pellet better.
The rifle’s behavior
At this point, I’ll comment on how the rifle performs. Shooting for accuracy I found the left-mounted cocking handle to be less of a problem than it had been when I tested the velocity. My procedure was to cock the bolt, advance the magazine, close the bolt, then pump the gun. This became a routine after a few shots, and it went surprisingly fast.
I rested the rifle on a sandbag for the shooting. Though it’s very light, the rifle was dead calm on the bag. The sights did not move one bit. And the MK-177’s trigger is so light and smooth that I found it very easy to shoot this way.
Pump effort identical to the 760
A reader asked me last time how this rifle compares to the 760 Pumpmaster in pumping effort. Silly me! I should have realized that the MK-177 is a 760 in another skin, but I tested my 40th Anniversary 760 just to make sure. The pumping effort is identical; or if there’s a small difference, the 760 is slightly harder because the MK-177 pump arm is a little longer.
The next pellet I tried was the RWS Hobby. These fit the clip a little tighter, and I could feel some resistance when the bolt pushed them into the breech. Again, I checked the target after the first shot then never again until I was through. I noted that this pellet moved over to the left side of the bull with no change to the sights. There’s a lesson to remember!
Hobbys grouped very close to Falcons, with the difference being due to measuring error more than any real practical difference. Ten Hobbys went into 0.858 inche…again, the group is fairly round.
Ten RWS Hobbys made this 0.858-inch group at 10 meters. This is so close to the Falcon group that it’s too close to call. Hobbys are wadcutters which cut cleaner holes, and may have lead to their group measuring slightly larger.
H&N Match Pistol
At this point, I was ready to declare the MK-177 to be an accurate multi-pump, but I had one more pellet on the table to test. And that one was the H&N Match Pistol pellet — another wadcutter. I’ve had remarkable results with H&N Finale Match Pistol pellets in some target rifles, but the straight Match Pistol pellet has never done better than average. Until this test!
Ten pellets went into a group that measures 1.239 inches between centers. No record there! But look at the tiny group that 9 of those 10 pellets made! It measures just 0.399 inches and is very round! Ladies and gentlemen, I think we have a winner!
From the results seen here, I think the MK-177 is a very accurate air rifle. It’s worthy of a 25-yard test with an optical sight. I’m thinking the red dot sight I’m using on the TX200 Mark III would be good for that. Before I do that, though, I’ll test the rifle with BBs at 25 feet.
So far, the MK-177 is a real winner! I enjoy the ease of use and the accuracy. If I didn’t already own a 760 and an M4-177, I would, perhaps, buy this one.