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Education / Training Crosman MK-177 multi-pump pneumatic: Part 1

Crosman MK-177 multi-pump pneumatic: Part 1

by Tom Gaylord, a.k.a. B.B. Pelletier

Crosman MK 177 multi pump pneumatic
Crosman MK-177 is a multi-pump version of FN’s SCAR.

Here’s an air rifle I’ve been waiting to test since this year’s SHOT Show last January, and now it’s Christmas Eve and I’m just getting started. Where do the days go?

There are 3 versions of the Crosman MK-177 multi-pump pneumatic. The one I’m testing is dark earth-colored with non-optical sights. There’s also a black version with non-optical sights and a dark-earth-colored kit gun that’s packaged with a dot sight instead of the non-optical sights. All 3 variations are pneumatic versions of FN’s Special Operations Combat Assault Rifle (SCAR) in Close Quarters Combat dress.

This is both a pellet repeater and a BB repeater; and, yes, the barrel is rifled. Pellets are fed from a plastic 5-shot harmonica-style clip that’s inserted on the right side of the receiver. BBs are fed from an internal reservoir that holds up to 300. To shoot pellets, the rifle must not have BBs in it, or a jam might result. So, it’s one type of ammunition or the other. Not both at the same time.

I will shoot the rifle with both BBs and pellets, but it’s the pellets that I’m most interested in. They offer the opportunity for accuracy, and I hope the rifle delivers on that promise!

BBs go into an internal reservoir through a covered hole located on the right side of the breech. Then, a sliding switch on the right side of the receiver is pushed forward, and the rifle is pointed straight down and shaken from side to side. This fills a small visible BB magazine that works by gravity.

Crosman MK 177 multi pump pneumatic BB magazine
The gravity-feed BB magazine is on the right side of the receiver. Push the black switch forward and shake the rifle side-to-side with the muzzle pointed down to fill this magazine from the internal BB reservoir. The BBs are visible through the slots cut in the receiver.

The 5-shot pellet clip is just a carrier. It stops in place for each pellet to be pushed into the breech by the bolt. Once the last shot has been fired, a light push in from the right ejects it out the left side of the receiver. Be careful outdoors, or you’ll lose the small clip when it pops out. Any time you want to unload the rifle, you can just pull the clip back out or push it through — nothing prevents it from moving.

Speaking of the bolt, the handle is located on the left side of the gun. This accommodates right-handed shooters best because your off-hand is free to work the bolt. In reality, it makes no difference since the gun must be pumped for each shot, which means it has to be manipulated anyway.

The forearm is the pump lever, and the rifle uses a short-stroke pump similar to Crosman’s 760 Pumpmaster. Pump the gun from 3 to 10 times maximum, depending on what you’re shooting. The pump strokes are light and easy, but the forearm/pump handle sticks a little when its stored. That may change as the gun breaks in.

Crosman MK 177 multi pump pneumatic pump arm down
The MK-177 has a short stroke pump. The forearm comes down like this for every stroke.

I intentionally asked to test the rifle with open sights, and am I ever glad that I did. I thought the sights would be plastic like the rest of the gun, but they’re both made from aluminum and built to last. The rear sight has a flipper with 2 aperture sizes, while the front sight is a simple post.

A sight adjustment tool comes with the gun. The front sight adjusts up and down for elevation (remember to do it in reverse of what you want on to target), and the rear sight adjusts side to side.

Crosman MK 177 multi pump pneumatic rear sight
Rear sight is made of aluminum and adjusts for windage. The sight has 2 different peep holes.

Crosman MK 177 multi pump pneumatic front sight
Front sight is made from aluminum and adjusts for elevation. A special tool is provided to adjust both sights.

This air rifle is made of a lot of plastic, and I know that will upset some shooters. But you can’t get a metal air rifle at this price point today. The shape is very realistic, but none of the conventional firearm controls work. They’re simply cast into the shell of the gun. And the buttstock doesn’t extend, making the 12-inch pull something you must live with. The buttpad is soft black rubber and sticks to your shoulder very well.

The trigger is surprisingly good. It’s so good that I think they designed it during the lawyer’s vacation! I’ll report the specifics in Part 2, but I wish their Benjamin multi-pumps had triggers this nice.

Finally, Crosman has managed to eke out a tad more velocity from this valve in a redesign. They rate BBs at 800 f.p.s. with maximum pumps, which is screaming fast for steel BBs! Naturally, that’ll be tested in the velocity test to come.

In all, I think we have a nice air rifle to consider!

author avatar
Tom Gaylord (B.B. Pelletier)
Tom Gaylord, also known as B.B. Pelletier, provides expert insights to airgunners all over the world on behalf of Pyramyd AIR. He has earned the title The Godfather of Airguns™ for his contributions to the industry, spending many years with AirForce Airguns and starting magazines dedicated to the sport such as Airgun Illustrated.

49 thoughts on “Crosman MK-177 multi-pump pneumatic: Part 1”

  1. Despite my occasional diversions into airgun snobbery, I love these low-priced MPPs.

    I own two Sheridan Blue Streaks with rocker safeties. They are above all accurate, but also light, and comfortable to shoulder as if I was born with them. Many consider these to be the high water mark of all Sheridans. I would have to agree.

    I also have a Crosman 1377c which was painstakingly converted into a 2289 with an 18″ barrel. I have polished the trigger and sear, along with adding a steel breech, .22 cal bolt, trigger shoe, Bug Buster scope and the muzzle brake from my Benjamin Discovery. It wouldn’t impress anyone on this blog, but when I am shooting with new or non airgunners, they are drawn to it like a moth to a flame. If anyone were foolish enough to offer me more money than I have into it, I would politely decline.

    I have and really like my Crosman M4-177, which is essentially a pumpmaster 760, but with a rifled barrel, better sights, and a much more ergonomic military gun exterior. So about the same as this gun.

    I am curious about the differences of this rifle to the M4-177. Is the fake magazine detachable, so that it can be filled with peanut butter and Ritz crackers, like God intended?

    Also, what is the deal with the trigger? Is it much better than the M4-177?? Please explain.

    They should have incorporated the adjustable stock of the M4-177 into this MK. That is a feature of the M4 that makes it really stand out. With the adjustable stock, I can shoulder it comfortably, and so can the much more diminutive Mrs. Slinging Lead.

      • Hello Mr. B.B.P.,

        Just an observation from a “novice shooter”. I own the black version of the Crosman MK-177 (with iron sights, from the manufacturer, originally). I love it! I also love my “tricked-out” Crosman M4-177! My MK-177 does have a storage compartment inside the non-adjustable butt-stock. Access is gained at the rear of the butt-stock, by removing the black rubber butt-pad. There are some slots for extra 5-shot “harmonica-style” clips, & the sight adjustment tool. It may sound convenient, but there is a down-side: The rubber pad is a little tricky to remove, & every time you do, it stretches, just a little. I can see where repeated removal/re-attaching would eventually stretch out the rubber to where it no longer fits snugly. I have seen/heard other “pro” air gun reviewers mention this same issue on various, reputable websites/blogs. Just an “F.Y.I.”. Thank you for all that you do, and all that you’ve done for this wonderful sport of ours!!! Safe Shooting!

  2. Maybe I’m being a little naive, but detachable front and rear metal sights? At that price? For Picatinny rail? It almost make sense to buy the gun just for the sights.

      • Yeah, you’re right. It’s just that seems nonsensical to me that a pair of cheap plastic sights cost about half the price of this entire gun, although is an offer. And at least in the pics, this thing looks nice. We now know it has a good trigger, and being a multi-pump means no recoil and smooth cycle. If this thing shoots well, it may be a must have.

    • They are very nice sights, indeed! Very robust build, very solid. Whenever I change out my iron sights for optics, I always make sure to save the sights. They always come in handy… Safe Shooting!

  3. Just yesterday, I was saying I have all the air guns I’ll ever need or want…..

    now, let’s see….where did i hide my credit card…. 🙂

    If this thing proves accurate….maybe in the Spring.

  4. My two cents. I purchased the black version of this gun about 8 months ago and really enjoy it as a plinker. I put a cheap red dot on it and can hit soda cans at various ranges from about 20 to 35 yards with ease. I wouldn’t use it for pest control, but with the “cool” factor it’s really a blast to just sit on the porch and plink at targets.

    After some breaking in, the pump handle doesn’t stick as much as it did in the beginning, and I found that by having a light grip on the handle instead of applying a lot of side pressure that the frequency of it sticking went down.

    As for the sights, I bought angle mounts on placed them on my MTR-77 just for looks.

      • Yes, if you look closely at the inside end of the pump handle (closest to the “magazine”), you’ll see two small plastic notches (or tabs) on either side of the interior. I believe that those two tabs are meant to “snap” the pump handle into place (once pumped the desired number of times) and keep it “locked in” while shooting. It does, however, tend to interfere with the actual pumping process. A little tricky to get used to. I have “adapted” to it. I’ve seen/heard other reviewers who down-right despise the design… Safe Shooting!

  5. I just hope it holds up well over time! I too have the M4-177 and it’s a neat little piece, but it’s already falling apart after less than 1k rounds. And while the adjustable stock is nice it’s fragile as heck…the first one sent from PA didn’t even survive shipping!
    I love military-styled guns so this one will probably wind up in my arsenal at some point, but it sure would be nice if Crosman could come up with a way to reduce the amount of pumps it takes to get off a shot-like the Beeman P3 for instance. It’s not like these things make enough power to do anything other than punch paper anyway, and it would sure make long sessions more enjoyable.

  6. ” It’s so good that I think they designed it during the lawyer’s vacation!”
    I am so gonna steal that 😉
    A truism that is just to true…and funny to boot.
    Have a Merry Christmas Edith and B.B. (and everyone else who frequents this place).
    Can’t wait to head to the range on the 27th to try out the new 12g O/U that Santa delivered last weekend.

  7. At first I really tought this rifle (the FN SCAR) was ugly but the look kinda grew on me.
    But I hate MPP! Why Crosman? WHY?

    I love CO2 guns, Crosman could have used the 1077 gun as a base for a whole bunch of military styled guns including this one.

    So I’m having my fingers crossed and I hope Umarex will bring one out based on the Steel Storm/Force platform and hopefully they can retain the folding stock.

    Merry Christmas to all my airgunning friends, I hope there’s a gun under each and everyone of your trees 😉


  8. Couldn’t wait and went to the PA website to see what specs Crosman and Edith advertised. 750 fps with “light weight” pellets in .177 is pretty darn fast for a multi-pump but are those pellets hobbys or the “green” light weights that have no accuracy to speak of. Only BB and time will tell when the speed and accuracy tests are done.

    Merry Xmas/Happy Holidays to all! And to our friends in Russia, I hope Father Frost brings you whatever your heart desires.

    Fred DPRoNJ

  9. If the gun is anything like the 760 I think they have a winner.

    Smooth shooting from the pump design, smooth trigger, (no smooth barrel) rifled barrel and I’m going to say it again rifled barrel.

    It will be interesting to see how the groups are when BB tests this one.

    And Merry Christmas everybody.

  10. I found a few things I didn’t like about this gun. I fixed most of them. First I found I was struggling to pump it. A dremel and some time took those plastic notches off the body that the pump catches on. I was also struggling to get at the tool and spare pellet clip compartment. So I cut a small notch in the bottom of the rubber butt pad so I had something to grab when I needed to access it. The third thing I could not fix is the cocking knob on the left hand side of the gun. I found this a very clumsy gun to operate because of this. Needless to say I don’t fire it much. I have guns that are much easier to operate. I will say though it is a very nice looking gun though. It’s more of a piece of a collection than a gun I’ll shoot much.

      • As it is out of the box you need something sharp. Slip it under the rubber butt pad and pry. Inside the butt is a place for 4 pellet clips and the sight tool. While you got the butt pad off make a notch in the bottom of it so you have a place your fingers can gain purchase for next time you want to get in there. I believe this compartment is shown in the rather sketchy directions. If it didn’t tell me in the directions I never would have found it.

          • I really think if they had taken the time they could have made this gun much better. I would have liked magazine storage and the selector lever that I originally thought was some innovative switch so you could go from bb magazine to pellet worked instead of being a molded in empty promise. I also think they should have put the cocking lever on the right. All what I was anxious to see, all the really innovative stuff was molded in and nothing more than window dressing and empty promises. I kind of feel like Crosman let me down on this gun that should have been and could have been so much better. They really need to hire me to design their stuff. Their current designers are really getting lazy.
            But, glad I could help show you a hidden feature that also could have been designed to be a bit more user friendly.

          • This is a gun I have several months of experience with. I’ve figured out what i like and do not like, what could have made it a great gun instead of a let down. I’ve looked at every inch of it, fired various pellets in it and fairly judged it and found it a gun that could have had all kinds of potential to be one of Crosman’s legendary guns. But with all the things that could have made it great all empty promises, it will eventually go the way of the AIR 17.

              • I’m right handed and this feels like it is designed for a lefty as far as getting it ready to shoot. I have the Crosman iron sights which are the same as the M4-177. I found it to be fairly accurate and reasonably powerful needing only 8 pumps instead of 10. It seems rather clumsy to me to cock it and out of the box I had to struggle with the pumping mechanism. I fixed that with a dremel and sanding drum. It is a formidable can killer and a close range squirrel gun. It’s just clumsy to get ready to shoot if you are right handed. I don’t want to step on any toes, so I’ll respectfully wait for BB to give you visual results. You need to know how to use military style sights to use it. With practice you should be able to shoot some decent groups.

                • I shoot right handed to. The 1720T needs to be cocked left handed. Took a bit to get use to also.

                  And ok I guess I can wait for BBs report.

                  But you talked about the rest of the gun. Why not that too?

                  • BB is way more scientific on that part. I am limited to around 12-13 feet right now, which is all I have really ever shot it at. My target is usually a pop can or some other target I can shred. So as far as this gun I don’t think I can give you quite as satisfactory answer as BB can. So I’ll just wait on him. At this point in his report I’m simply looking at what it has and doesn’t have I wish Crosman would have put more effort into.

                    • Well me and my daughters have fun with the airsoft pistol at the closer distances. So if thats what you can shoot at cool.
                      Hopefully sooner than later they will get their act together. Right?

                      And have a good Christmas.

                • The configuration is strange, but as a lefty, it really does feel like it was created for a left-handed shooter. The configuration feels completely natural to me, so I know it feels awkward for the other 90% of the population.

                • Never seen the HK-91? (or HK-93, or precursors)(Not airgun look-alike, I’m talking the real thing)

                  Cocking handle is way up near the front sight, on the left side. Takes a bit of effort to pry the handle outward (the leverage is used to unlock the bolt) before one can pull it back to just before the receiver.

                  • I have sen them but never used one. I tend to like things that can be used by a right handed shooter or both. Guns designed for left handers just feel too clumsy to me trying to get it ready to fire. The muzzle tends to go all over the place as I struggle to cock it. On a range that will get you thrown out. Spo I stick with things like my AR or AK, things where I can keep safe control over the gun.

      • Yes, the butt pad opens. Long fingernails help, otherwise you may have to gently “pry” it off with a slim, flathead screwdriver. Use caution. I don’t recommend even removing the butt pad. Not the best design… Safe Shooting!

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