Home Blog  
Ammo Winchester MP4 CO2 rifle: Part 4

Winchester MP4 CO2 rifle: Part 4

by Tom Gaylord, The Godfather of Airguns™
Writing as B.B. Pelletier

Part 1
Part 2
Part 3

Today’s report is the final part of the guest blog from HiveSeeker. He tells us about the various pellets he tested and gives their results.

If you’d like to write a guest post for this blog, please email me.

Over to you, HiveSeeker.

Winchester MP4 CO2 rifle
Daisy’s Winchester MP4 is a realistic and fun-to-shoot military replica pellet rifle. The gun is shown here with added Leapers UTG 3-9×32 Bug Buster scope and AR-15 rubber recoil pad.

This report covers:

• Scope notes
• More pellet testing
• I know there’s something going on
• The Winchester trio
• RWS Diabolo Basic pellets
• RWS Hobby pellets
• H&N Match Pistol pellets
• The magic bullet? Beeman hollowpoint coated pellets
• Retesting the best
• Conclusion
• Other military pellet rifles to consider

In Part 2, I found five pellets that would group 7/8 of an inch (0.875 inches) or better with the Winchester MP4 CO2 rifle at 10 yards (Crosman Destroyer pellets, Crosman Destroyer EX pellets (sold only in discount stores), Crosman Premier Hollowpoint pellets, H&N Finale Match Pistol pellets, and Air Arms Falcon pellets). This was about as good as I expected based on my research before purchasing this gun. However, I’d hoped that I could do better, and most of the reader comments on this blog expressed even greater concern with the mediocre accuracy of this gun than with the ammo feed problem. I’m pleased to report some slightly better news.

Scope notes
But first, I made a minor modification to my scope setup. I mentioned the trouble two other shooters had sighting through the Leapers UTG 3-9X32 Bug Buster scope I mounted on this rifle. I had positioned the scope for my own eye relief, and eye placement proved to be a lot more critical for this compact scope than it is with my full-sized Leapers UTG 4-16X40.

However, at least part of the difficulty they experienced may have been due to a fairly low Picatinny rail on this rifle. When the included factory scope rings loosened after 300 shots, I decided to try a different style mount and also decided to go with high-profile rings. I was surprised at how much easier it became to sight through the scope — especially since I would have thought I wasn’t having any real difficulty before. For most shooters, I believe high-profile scope rings will be the way to go on this rifle. With my new scope setup, I was ready for some final accuracy testing.

Winchester MP4 CO2 rifle High Scope Mount
High-profile scope rings makes it a little bit easier to sight through the UTG 3-9X32 Bug Buster scope on the MP4’s low Picatinny rail.

One minor note here. On Picatinny rails there’s usually a little play in the scope mounts within the individual recoil grooves, and I usually slide both my mounts forward until they contact the forward stops and then snug them up right there. This is the direction the laws of inertia demand that the scope and mounts will want to go in relation to a rifle recoiling backwards beneath them (especially pneumatic or CO2 guns with simpler recoil than a springer). If the mounts are already braced against the forward stops, then there’s less chance for them to slip. However, on the Winchester MP4, I believe the semi-auto bolt re-cocking generates some recoil in the opposite direction — this may have actually loosened my initial scope installation. This time, I braced both scope mounts against the rear stops, and they seem to be holding fast, so far. I don’t have the equipment to verify this recoil theory, but it’s something to try if you run into a similar problem.

[Editor’s note: While Picatinny rails and Weaver rails both have cross slots to stop the rings from moving, Weaver slots are 3.5mm wide and Picatinny slots are 5mm wide. That’s the reason for the extra slop when Weaver rings are installed on Picatinny bases. And, for airguns, the pins should touch the rear of the slots.]

More pellet testing
I continued testing with seven new pellets, shooting 10-shot, 10-yard groups outdoors from a benchrest. I shot three groups with each pellet, and reported the best of three below. With my original accuracy testing, all the pellets I tried grouped about 1 inch, give or take a little. However, this time, the groups were generally tighter — even with pellets I’d previously tested. I believe this barrel may have a break-in period — roughly 500 shots by my estimation — and is now smoothed out a little. For this test, I used digital calipers to provide more exact group measurements — though, even with my sharp eyesight and a science background, you can take that third decimal place with a grain of salt!

I know there’s something going on
There definitely seems to be something going on between the number of pellets in the rotary cylinder and accuracy. I’d already mentioned that the last two shots of my 10-shot groups, involving a magazine swap, often opened up the final grouping. Remember that the ammo mag has 8-round cylinders, so finishing off a 10-round group required switching to a cylinder with only the two final pellets loaded. I could blame the repositioning of the rifle between magazine swaps, except that this is not a problem I’ve had with rifles that require pumping or cocking and get repositioned with every shot. This time, I kept specific track of when my final two shots opened up a group, with the results illustrated below.

Winchester MP4 CO2 rifle Last 2 Shots
You can see how the final two shots (circled) opened up each of these 10-shot groups. Left-to-right are Crosman Premier Super Match pellets, RWS Hobby pellets, and Air Arms Falcon pellets.

This batch of testing also confirmed something else I thought I’d noticed before — groups often started off very small, then opened up as I emptied the magazine. Obviously, shooting more pellets will continue to open up a grouping. What I’m saying is that shot 10 was much more likely to miss the bullseye than shot 1, rather than having a similar probability of hitting or missing it. With this semiauto, I could lock myself into a rested shooting position and do nothing but breathe and squeeze the trigger for 8 shots. Barely moving, my aim and hold were rock solid. However, I almost felt like a spectator at times as I watched pellet strikes begin to roam wider and wider around my point of aim. I believe this is the same phenomenon I observed with my final two shots of each group. My best guess is that adjacent pellets in the magazine cylinder help reduce some CO2 blow-by, or that a full magazine cylinder does not shift or flex during firing as much as an empty one.

Winchester MP4 CO2 rifle target

On the left, the first three shots with Beeman coated hollowpoint pellets go into 0.261 inches, center-to-center. Keeping my fingers crossed at this point! But the fourth shot (circled) opens this group up a bit more to 0.323 inches. Six increasingly scattered shots later, the final group on the right is now even broader at 0.682 inches (that fourth shot is circled on this target as a reference point). This pattern was observed repeatedly. This was not the best example I saw. It was just the one I interrupted to photograph.

The Winchester trio
Since this is a Winchester air rifle, I felt duty-bound to put the Winchester pellets through their paces. While they were the poorest performers of all the new pellets, their best groups were all still 1 inch or less: Winchester hollowpoint pellets (0.826 inches, center-to-center), Winchester pointed pellets (0.859 inches), and Winchester round nose pellets (1.000 inches exactly). As mentioned, the Winchester hollowpoints extended past the front of the rotary cylinder when fully seated and had to be pushed back in slightly before shooting. However, they caused no jams or other firing problems.

Winchester MP4 CO2 rifle Winchester Hollow Point
The Winchester hollowpoints extend past the front edge of the rotary cylinder when fully seated.

RWS Diabolo Basic pellets
The RWS Diabolo Basic pellets yielded the next largest group of the bunch, with its best-of-three at 0.791 inches. This pellet also produced the largest group that I observed during this second round of testing — 1.324 inches.

Winchester MP4 CO2 rifle RWS Diabolo Basic
Ten RWS Diabolo Basic pellets grouped inside 0.791 inches –close to the best that was seen in the first round of accuracy tests.

RWS Hobby pellets
The RWS Hobby’s smallest group measured 0.644 inches. This was the best group I’d seen from this gun so far. It’s approaching the as-of-yet elusive half-inch mark, but not quite there.

Winchester MP4 CO2 rifle RWS Hobby
Ten RWS Hobby pellets in 0.644 inches — easily my best group up to this point.

H&N Match Pistol pellets
I’d tested the more expensive H&N Finale Match Pistol pellets last time, but then I read about H&N Match Pistol pellets actually outperforming the Finales in another gun I own. That’s why I ended up with a tin of these to try. At 0.716 inches, they grouped slightly better than the Finales (even with retesting, as you’ll see in a minute) in this gun, too.

Winchester MP4 CO2 rifle H&N Match Pistol
The H&N Match Pistol pellet, at 0.716 inches for 10, outperformed both previous and repeated testing of the H&N Finale Match Pistol pellets.

The magic bullet? Beeman hollowpoint coated pellets
Okay, I’ll concede right up front that half-inch groups at 10 meters aren’t all that magical in today’s airgunning world. However, with a review quoting Daisy Customer Service as stating that MP4 owners should expect 1-1/2 inch groups at 10 meters, and with no measured groups under 1 inch reported by anybody, I was pleased to finally break the half-inch barrier with Beeman hollowpoint coated pellets.

I did not have high hopes for what is literally the cheapest pellet I tested. However, a single Pyramyd AIR review mentioned it performed well (thank you, DaveTee!); and, for under five dollars a tin, it went into the shopping cart. I shot this pellet last, and it surprised me. My three test groups yielded 0.682 inches, 0.386 inches and 0.442 inches. At the eleventh hour, I’d finally found a pellet that could shoot under half an inch. While one thing that became clear during accuracy testing is that my rifle does not perform the same with specific pellets as other’s MP4s, the Beeman hollowpoint coated is definitely one to try for anyone who owns an MP4, especially at this price point.

Winchester MP4 CO2 rifle Beeman HP Coated
Thar she blows — these two groups shot with Beeman hollowpoint coated pellets clock in at under half an inch, at 0.386 and 0.442 inches, left to right. (Yes, the pellets are black.) Summer sun heating the barrel on one side caused the point-of-impact shift that can be seen here.

Retesting the best
To wrap up Part 4, I wanted to retest the best-performing pellets from before, which had all grouped 7/8 of an inch (0.875 inches) or less. I was pretty sure one or two could do better, and it seemed that my rifle was starting to produce tighter groups than it had straight out of the box. These were my results: Air Arms Falcon pellets (0.622 inches, beating out the RWS Hobby pellet for second place), Crosman Destroyer EX pellets (0.630 inches, taking third place and booting the RWS Hobby pellet to fourth), Crosman Destroyer pellet (0.742 inches, just a hair better than before), and H&N Finale Match Pistol pellets (0.963 inches, actually a little wider than first time’s 0.875 inches and still getting beat out by the H&N Match Pistol pellet). A small surprise were the Crosman Premier Super Match pellets (0.707 inches) and Crosman Competition Wadcutter pellets (0.720 inches), which I used for initial sighting-in of my new scope mount setup. Both bettered their original 1-inch groups by more than a quarter inch. Again, I believe this barrel is now broken in after 500 shots or so, contributing to these tighter groups and providing better overall accuracy than we saw in the first tests.

Winchester MP4 CO2 rifle Air Arms Falcon 2
The best of the retests was the Air Arms Falcon pellet, second-best to the Beeman hollowpoint coated pellet, but grouping almost twice as broad at 0.622 inches.

Below is a summary of best groups one inch or better from all accuracy testing:

Winchester MP4 group sizes

While discovering the Beeman hollowpoint coated doubles my effective shooting range to around 20 yards for a 1-inch target, it’s a shame that this gun seems to be a “one-shot wonder” that shoots best with only one specific pellet. From the list above, there’s no single pellet type that this gun seems to prefer as direction for additional testing, so I hope that blog readers will be kind enough to comment if they find other pellets that group under half an inch in the Winchester MP4.

Other military pellet rifles to consider
For the conclusion to my evaluation of the Winchester MP4, I’d like to mention some of the other military replica pellet rifles prospective buyers might consider if they decide that the MP4 is not for them. (BB-only rifles and machine guns are not included here.)

I’ve already mentioned the MP4’s historically older sibling, the Winchester M14. A replica of its namesake, this rifle is also a dual-CO2 canister BB and pellet semi-auto. It uses the same ammo mag and offers the same velocity as the MP4. However, it has no scope rail and many don’t like the fact that the stock is composite instead of wood.

The unquestioned dominator of the military pellet rifle arena remains the Crosman M4-177. This M4 replica is a reliable single-shot BB and pellet pneumatic and bears the coveted Gaylord “Tom’s Picks” seal in the Pyramyd AIR catalog. It’s available in a variety of tan or black color and accessory combinations. The new Crosman USMC MOS 0311 Rifleman (an exclusive Crosman variation of the M4-177) appears to be another variant of this very popular replica. This is the gun I had in mind when I mentioned that more accurate rifles than the Winchester MP4 are available for half the price.

The Crosman MK-177 is a replica of the Magpul Masada (now being produced as the FN SCAR). This composite-stock pneumatic offers higher velocity and similar accuracy to the M4-177 (also beating the Winchester MP4 in the latter department, and for half the price). This rifle is a BB and pellet single-shot. B.B. Pelletier recently used the MK-177 to test the Leapers Accushot Scout Scope. While many disparage the bolt placement on the left side of the receiver, I own — and love — one of these rifles and never minded it (this is a replica — check on which side the bolt is actually located on the Magpul Masada). The MK-177 is available in tan or black and has two kit variations.

The Crosman Crosman MTR77NP is an M16 replica that is a single-shot Nitro Piston gas springer. This pellet rifle offers the highest velocity of any of these military replicas but requires heavy cocking effort due to the short barrel. It’s available in only black but comes in open-sight or scoped versions.

If you actually own an AR/M4 firearm, the Crosman MAR177 AR-15 Upper PCP conversion kit replaces the firearm upper with a .177-caliber competition precharged pneumatic unit. Designed specifically for 10-meter competition, velocity is a very nominal 600 fps. This is the most expensive option for a military pellet rifle (and a significant detour from the standalone guns listed here), but it seems like an ideal way to expand where and when you can shoot your military long gun.

The Beretta CX-4 Storm is an 88-gram CO2-powered replica of the tactical firearm of the same name. This semiauto’s claim to fame is the 30-pellet belt magazine, capable of ripping through a tin of pellets in no time. Open-sight and red-dot versions are available, though a scope can be mounted on the Picatinny rail.

The Gamo MP9 copies the B&T MP-9 9mm SMG and is unique among the CO2-powered BB submachine guns in handling pellets as well. Interestingly, this gun is listed as using the same ammunition magazine as the Winchester MP4 and M14, making it a 16-shot semi-auto (with the magazine flip). I included this odd-gun-out because it has a (collapsible) stock and scopeable Picatinny/Weaver rail.

Winchester MP4 CO2 rifle Flambeau Tactical Case
The Winchester MP4 is a fun military replica that, despite some issues and limitations, will keep you looking like a well-armed commando whenever you feel the need to reconnoiter the backyard.

The options for new military replica pellet rifles are very limited at the moment. I hope that this blog has sufficiently informed readers about the Winchester MP4 to make an educated choice if buying one — or to achieve the best performance from their rifle if they already own one. I also hope that manufacturers will look to success stories like the Crosman M4-177 as well as the burgeoning airsoft market and bring some novel products to this mostly unexplored marketplace.

Editor’s final comment: HiveSeeker has done a super job in testing, researching and documenting his work on the Winchester MP4. I think his report will stand as the best article written about the airgun for a long time.

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.

70 thoughts on “Winchester MP4 CO2 rifle: Part 4”

  1. Well done hiveseeker!

    Greatly appreciate your time spent with the MP4, the time to create great photos and most important your time spent writing about your journey for our benefit. Thank you.

    Don’t quite understand when you say, “….it’s a shame that this gun seems to be a “one-shot wonder”

    If you find the one magical pellet that is the most accurate in your airgun why do the other pellets matter? Buy lots of those magical pellets and never look back when you’re done with your pellet testing.


    • Thanks, all, for some very generous comments. BB has a great crew here!


      While it’s great finding a pellet that works well in your gun, it’s even better finding a variety of pellets that all work well to choose from–like wadcutters for target shooting, or pointed and hollow points for hunting (if your gun generates enough muzzle energy). I have a couple guns that really “like” a wide variety of pellets, and that makes them more versatile.

  2. Hiveseeker,
    Bang-up job! Your dedication to this gun is impressive! Very thorough and informative review. I’m glad you finally found a pellet that groups well in it. Ain’t it nice when you find an easy way to double your effective range?! Keep up the good work and the rewards will keep coming.


  3. Hiveseeker

    This has been a fantastic series from you. From the comprehensive test, and the trouble shooting, to the impressive photography (i really liked the inset photo effects) it has been an exhaustive effort. Thank you for all the sweat you have put into it. I think BB owes you for the vacation time.

    You earn bonus points for “reconnoiter”. Great word.

  4. Hiveseeker,this has been a “one hit wonder”report and will be a gold record report! In other words I’m not into these type of guns BUT you have a way of getting me to read and hold my interest about a gun that I don’t care for.That’s a complement. I’ve never been what ya call one who enjoys reading but this blog has changed that over the past few years.So thanks to all here this gets read every morning before the first cup of java is down.

  5. Excellent review, HiveSeeker!

    I am also one who is not a candidate to purchase this rifle. Regardless, I read just about every word of your report because it is professionally done, thorough and very interesting.

    Thank you for your effort.

    • steve and Jerry in Texas,

      Thanks, gents. My experience has been similar–at first, I started by just reading the blogs for guns I was considering purchasing, or articles that applied to me like scope mounting. Then those historical blogs on old airguns became interesting, and now I’m reading every word of every new post (and have well over a year’s worth of older blogs archived for reading). It’s broadened my horizons, and I’ve been surprised at the new things I would not have learned otherwise. Glad you enjoyed the read–BB’s rubbing off on me!

  6. Hiveseeker, I enjoyed reading your excellent review. I was impressed by your attention to all of the details that you examined. Has anyone tested the Beeman coated pellets in the Daisy M14? Once again, thanks for your report. Ed

  7. HiveSeeker,

    I enjoyed your report.

    I took six young men shooting yesterday. Most of them are ex-military or in ROTC. I had a Garand and US-Property M1911A1 for them to shoot, and plenty of ammo. They had lots of fun, and I enjoyed hosting them. Many recreational shooters would enjoy plinking in their yards and basements with rifles like this replica airgun. Thanks for a great report.


  8. Drive by comment off subject.Three squirrels this morning.Two head shots and a shoulder shot on a very large fox squirrel witch has found a new home in the crock pot with cream of mushroom soup.The Polymag removed the front shoulder.Airforce Escape in 25 cal.

      • Gunfun1,well yes and no,its just easyer to call it a Escape rather then say the TalonP with 24” barrel in 25 cal. Its the same thing as the Escape. I’ve only got four polymags left but PA send my order out this morning for Baracuda Hunter Extremes,Polymags,Baracuda 31 grns,and the old reliable JSBs all in 25 cal.So I should be in good order for the fall and winter hunting. Can’t wait to try out the Hunter Extremes hoping they group good along with good expansion.If not they will just set on the self like the Eunjins 43 grns.They would be just fine for ground hog and critters like that but they don’t cut the mustard for staying inside the inch.Buy the way Gunfun1 the squirrels hate that bipod you recommended me to get! everytime I rest the Airforce on it,one falls from a tree.I like that foam hand grip that goes a long way down the sides.I shoot of the sides of it at times when I don’t have the time for a adjustment.For $31.00 bucks you can’t beat it.

        • steve
          I’m glad you like it. And I use mine alot now. I have been using it in the standing position alot out in the back yard. And I have been trying to improve my standing free hand shooting and I think the bi-pod has been helping me get better shooting that way also.

          And yep them squirrel will start getting smart on you when they see you coming. The squirrels don’t hide from me any more they run. I wish I still had my old German Shepard I had when I was a kid. He was a heck of a squirrel dog.

          • Gunfun1, more power to ya on practicing off hand shooting.I ain’t even gonna try it because I could never shoot off handed in my life and no need trying at my age.BUT give me a rest with my shoulder against a tree and they don’t stand a chance. I can hit the kill zone on a deer without a rest or a groundhog standing up but trying to take out a dime sized kill zone I’m all over it zigging and zagging 50/50 chance of intentional POI.I just would have to use a shotgun.Not much challenge to that.

            • Steve
              I just hope to get better. I became dependent on resting up against something. So I’m trying to break myself of that. Its definitely more of a challenge shooting without a prop or restaurants that’s for sure.

        • I’ve found the hunter extremes perform absolutely amazing, but weren’t the mist accurate in any gun I’ve tried, in 22 anyway which is a shame, Im tempted to find a gun that groups with them just to use them, they expand so nicely. I don’t know if you’ve tried the HXs but let me know if they group good for you, maybe they’re better in 25 or 177?

          • RifledDNA,I’ll let ya know what they do in the Airforce Escape 25 cal.Should get um Friday.If they will do a raged hole at around 60 feet then I’ll try um out until the leaves start to fall then I’ll probably go back to Baracuda round nose 31 grn. for long distance accuracy if these others don’t don’t do as well. I’m hoping I can milk 150 feet out of a polymag and stay in the inch. Baracudas will do it and JSBs but I gonna guess Poly’s won’t for me.

            • So I lied, the extremes I have are 177. And after flaring out the skirts on crosman pointeds, which gave the highest speed/power but fit too loosex, in my pc77 I was able to get em on target. I think the flaring gave them a little more power too, took a rabbit last night at ten meter that, with unintentional holdunder, but a perfect heart/lung! Broke right through top part of shoulder blade and buried 3/4th into the inside of opposite shoulder, dropped and didn’t kick. That’ll work!

  9. Very professional job there. All this shooting makes me jealous. I’m in the toils of moving, and between all the cardboard boxes, I don’t know when I will get my guns in action again. 🙁


    • Matt61
      That’s one thing I can say that I don’t like to do is all that packing, boxing up and loading and unloading when moving. But hopefully you are moving to a place you want to be at.

      And remember to keep your pellets safe and sound when you move. Don’t let them get knocked around you know. Ain’t nothing worse than opening up a tin of pellets and finding bent ones.

    • Matt,

      Believe me on my 4th moving, all my stuff was packed in 3 days and unpacked into “ready” condition in 2. And this was not a small stuff: 6 cu m, my books being the heaviest and most sizable part. It’s just a matter of experience and proper markings 🙂

      I divide all my boxes into 3 echelons by priority and each one has marking with its former and future destination. E.g. “clothes, winter, Pr.3 (green stripe). From: wall storage, left. To: big built-in wardrobe, left”. Priorities are collected by loaders into piles (color to color) then I just unpack it according to plan. Guns, ammo and gun safes are moved separately, by myself and my friend in my friend’s car (he’s got huge Landrover) and controlled by me alone on the place. Same procedure for my GF stuff: boxing, planning, moving, unboxing. May not be the perfect way, but works every time for me.


  10. Hiveseeker,

    Before I make any comments or ask any questions please allow me to say that your report is one of the most thorough and exhaustive I have yet to see on pretty much any airgun. Especially in your search for the best pellet and reasons for the accuracy issues with this rifle. I might add that only B.B.’s reports on the Marauder (and one or two other guns I can’t think of at the moment) are more complete.

    I also have an air rifle that is a surprising “one pellet wonder.” As one other reader observed, that would be ok if it shot that one pellet remarkably but it doesn’t. That is my Walther Lever Action. The ONLY pellet it shoots with reasonable accuracy is the Meisterkugeln and the best it does with that pellet is 1/2″ to 1″ at 25 yards. No other pellet even comes close. I have always been mystified by that. It makes for a great plinker but at the price point, $440, I would have expected better.

    I would love to have a military styled rifle as part of my collection; however, since I really dislike multi-pumps, love accuracy and require pleasing design the only gun I can entertain right now is the
    MTR77. Unfortunately, the cocking effort for that gun is just too much. So, this is a plea from me for Crosman to reduce the velocity on that rifle to 850fps to 900fps. Hopefully this would reduce the cocking effort to around 30lbs. to 35 lbs and probably improve accuracy. Then I would be able to justify adding this rifle to my collection.

    You mention one other gun that has always intrigued me, the Crosman MAR177 AR-15 Upper PCP Conversion Kit. Can anyone tell me where I can buy a complete Lower Kit for this Upper so as to end up with a complete rifle. Specific models would be helpful.

    Anyway, keep up the good work.


    • G & G,

      Thanks for the (overly) benevolent compliments! One amazing thing the internet has done is save us all from having to do our own individual product testing! I’ve found others’ experiences to be invaluable, and sometimes even one short comment–like DaveTee mentioning the Beeman hollowpoint coated pellets in a Pyramyd AIR review–can make a tremendous difference.

      I can’t help on the MAR177 AR-15 Upper PCP conversion kit (except to reiterate that it is designed to be a 10m competition rifle so should be quite accurate). From the requirements you’ve laid out, I suspect finding a rifle to use this conversion on might be what you are looking for, but I’m sure it won’t be cheap.

      On the Crosman MTR77NP, in addition to the very high cocking effort you mention, I have read that it is not terribly accurate (BB–I believe you stated recently you did a blog on that one?), so I suspect for what you want you will need to keep looking.

      I concur that there should be more options in this market, and there is definitely money on the table–some of it definitely mine!–for any manufacturers willing to oblige.

  11. Hiveseeker,I,ve been embarrassed here before once or twice so here I go with the question.I have never heard of the sun heating the side of a barrel up and then the pellet or bullet group swaying to that side? Is this a inside joke that is going over the top of my head or is it fact? If it is fact please inform me.

      • steve and Bradly,

        Come in, gentlemen, and have a seat. I’ve been waiting for you! I KNEW I would get a couple (very legitimate) questions on this! Here’s the saga:

        This blog actually got delayed a few weeks because it’s just been too miserably hot to shoot outside. I completed it by rising early on Saturdays and getting in some scope-and-pellet time before the sweat just started running down my arms. On the morning in question I shot a little bit later than usual despite the heat because I was almost finished. As the sun came up, it was hitting the right side of my gun and I began to notice something odd: My groups slowly and consistently began drifting left!

        Now, I accuracy tested each pellet three times (a time-intensive process that this perfectionist might drop if he does another blog!). That morning, as I wrapped up with the Beeman hollowpoint coated pellets, I was also re-testing my original best performers from Part 2 of this blog. Instead of testing each pellet three times in a row, I mix it up a little so that if I start getting tired (or if it gets windier, or if the temperature changes enough to affect CO2 performance, etc.) it doesn’t affect all of my testing for that particular pellet. That day, I started and finished with the Beeman pellets, but shot a number of other pellets in between. If I were to post photos of all the targets I shot once the sun hit my rifle barrel, you would see them ALL progressively “walking” left and a bit down, consistent as you please! The two Beeman targets shown were the start and end of that odd journey, and were therefore the farthest apart.

        I’ve never read about this happening anywhere else, either. But what I believe was occurring was that the long, extended barrel shroud on the sun (right) side of the gun warmed and expanded on that side, slowly shifting the muzzle of the barrel (where it is held by the barrel shroud) to the left. I don’t think the barrel itself was affected–or we’d all have heard of this before. I think the warming shroud expanded on one side and pushed it a little.

        And no (even though the question does make you good detectives), it wasn’t the scope. The next time I shot the rifle, my zero was spot-on again and has stayed there.

        BB, I would love to hear an informed opinion on this.

        • Hiveseeker,thanks for your reply and I guess that is as good reason as any until its every studied and proved one way or the other.I’ve seen the pressure in my Mrod go from 2500 to 2650 just from setting in the truck for only a short while on a hot day.That would certainly be a factor in poi.I’ve had some guns in the past that the first shot would always be a little off then after that mini warm up it would shot every one were I told it to go.My 22 rim fires were bad about that and also my 22 mag. After the first shot every thing was go but problem is the first shot is the one you need most when hunting.I do usually take one shot with the 22 Mrod before heading to the woods just for good measures because it to will do that.I have even took a few target shots while hunting with the Mrod because it is so quiet! sycamore balls make great exploding little puffs when hit.

  12. Speaking of one pellet wonders, has anyone had a gun that grouped great with rws supermags, and nothing else, then found a lighter replacement pellet that grouped just as well? My pc77 only groups with the supermags but I need a lighter pellet, anything dimensionally the same but under 8 grains? Cphp? All my stores are out of cphp so guess I’ll have order some tins after reading pc77 reviews of what pellets are good.

    • RifledDNA,

      Have you tried all of the JSB pellets under 8 grains? I don’t know dimensionally how they stack up against Supermags but you usually don’t go wrong with JSB’s.


      • I have jumbo monsters, foolishly, though at the time it seemed like a good idea because I wanted to test a guns capabilities with heavy pellets…. anybody need a full tin of them? In 22

        • I wouldn’t mind trying some Monsters in my 392,it still likes round balls the best before the Crosman pointed. I don’t have any JSB’s to trade but how about something 7.4 Daisy precision max pointed?


  13. Hiveseeker
    A thoroughly pleasing, and in-depth look at the Winchester MP-4 Co2 powered rifle. In fact, it wouldn’t surprise me to hear of Winchester shipping the complete four part blog alongside the rifle. With the author’s blessing, of coarse. Since my early teens I have developed a respect for co2 powered guns. Christmas, 1963. My best friend and I receive air guns from Santa. I snagged a Crosman 1894 Winchester bb gun, while my friend was the proud new owner of a genuine Crosman 140( ? ) co2 pellet rifle. (I am merely taking my best educated guess as to the model no. Those who own or collect older Crosman co2 guns would have a better idea of model no. based on the date). He also received a 5 pack of co2 caps, and as BB has explained once or twice, the 12gm co2 caps sold in those days were less then reliable when it came to storing the co2 gas. . Two caps were later proven to be empty, and I believe the gun got approximately 40 shots a cap for the remaining three. It didn’t take a genius to see that a 12 year old boy could scarcely afford this extravagance. So, with heavy hearts and much regret a week later, he traded his prized Crosman co2 powered rifle for a break barrel of some forgotten vintage. Believe it or not, we still talk in reverence of that Christmas rifle of so long ago whenever we get together. I currently own a Czech made TAU200 co2 powered target rifle. I purchased it used about 5 years ago, and its accuracy never fails to amaze me at 10 meters(7.5 in my indoor range), while getting 72 accurate shots per cap. I sometimes store it for 3-4 weeks between shooting sessions, without loss of co2 thanks to BB’s recommendation of applying Crosman Pellgun oil to each cap.

    • Titus Groan,

      After being as avid an airgunner as a 13-year-old could possibly be on a $1-a-week allowance, and then a hiatus of about 30 years, I’ve finally entered the CO2 arena. During my “hiatus” I still had an airgun or two under the bed and would shoot occasionally. Everything I’ve owned until a year ago has been a pneumatic, and I guess I’m just tired of pumping! (I’m absolutely certain age has nothing to do with it.) Exactly as you said, a 13-year-old’s allowance would never have supported a CO2 gun in those days, but I am just loving it now. Semi-auto, very little recoil, and did I mention no pumping? (Again–age is not a factor here!) Everything I’ve been looking at buying lately has been CO2 . . . until I can move up to a PCP, of course! And you don’t have to pay much to get a nice CO2 gun, as BB’s recent blogs on the Crosman 2240 (pre-mod) and Crosman 1077 show.

      • Hiveseeker,

        Iif you love CO2 guns as much as I do I have one to recommend. The Umarex Fusion CO2 rifle. It’s quite accurate (1/2″ at 25 yards), shoulders very nicely(for me at least) and the weight it great for off hand shooting. I thoroughly enjoy this gun. I got the replacement CO2 cap from Archer for mine and have had no problems. I highly recommend this one.


        • G & G,

          Thanks! I’ve heard this gun mentioned repeatedly in CO2 discussions, though the Hammerli 850 AirMagnum seems to have a more avid following (though for $120 more–I’m still on an “allowance”, though it’s a lot bigger than it used to be!). Given a choice, I think I’d like to move my game up to a .22 with my next purchase, though the Hammerli 850 apparently has some issues in that caliber. I wasn’t aware of the Archer accessories for the Fusion, though–that does make it more interesting!

  14. Really nice job, HiveSeeker! Looks like this isn’t a bad gun, just another one with quirks. All airguns have quirks in my opinion….

    I hope you’ll see fit to do another report on a different gun inthe future!


  15. Hiveseeker, excellent job on a truly in depth evaluation. I own a Crosman M4 and it is very accurate with a good scope out to 25-30 yards but I have noticed also that a high set of rings is needed for the picatinny base. Nice shooting!.

  16. As you shoot the CO2 makes the barrel colder and colder. I wonder if that is having an effect on the last shots opening the group. It would be easy to test. Just wait a few minutes between shots.


    • Mlke,

      That’s a good thought, though if that were the case I would expect subsequent groups to start off opened up instead of starting small and then widening after a few shots. It doesn’t take long to swap the ammo mag, and if a chilled barrel were causing an issue it wouldn’t warm up that quickly.

      Good detective work, though, as this was something that had not occurred to me. I had to think about it for a few minutes first before reaching the conclusion above.

  17. I finally found where the Stoeger match pellets my QB-36 likes so well/product/beeman-h-n-match-177-cal-8-18-grains-wadcutter-300ct?p=460 My Airmaster likes them too! as a matter of fact they shot well in everything I tried them in and these are $5 cheaper!

  18. Too bad this airgun doesn’t work better. I already have a CO2 repeating air rifle with so-so accuracy. But, at least when I do pull the horrid trigger on it, it always blasts out a .177 pellet. That would be my 8-9 year old Crosman 1077. I don’t care for the “tactical” design, and do not want my air rifles to look like military weapons. I do like all the Weaver rail on this airgun, as I am just entering the world of night vision ratting with a NV monocular and an infrared laser sight. Mounting this stuff on my Custom Shop 2400KT will be much harder than on this Winchester.
    That 1077 just doesn’t have the accuracy, and consistency I want in a ratter. My 2400KT will show me quite a few center top center 11 yard groups of 0″, or very close to it. The 1077 throws way too many fliers. That’s another thing. While the 1077 may throw 1.5″ out fliers, with the 2400KT, I consider a “flier” to be 1/4″ out of the main group.
    I may order the Delrin Barrel Stabilizer Bushing for the 1077, as many owners complain about excessive muzzle end play of the barrel. It’s $14.00 + $2.60 shipping. That’s about one quarter the price of my 1077, but maybe worth a try. But, that 1077 will still have the worst trigger of any pellet gun I’ve ever fired. And, it is WAY louder than my super quiet 2400KT.
    And, since I live on the big island of Hawaii, I can’t even find the 88 gram CO2 cans here. The latest is that nobody will ship ANY CO2 cans (or any batteries for that matter) by air. And, nobody wants to ship to me by barge, which takes about 6 weeks, and is cheap, but requires a little effort from the seller. Crosman wants well over $100.00 to ship me an airgun. Amazon often ships to me for free.

    Though I wanted to read a review about a Winchester MP4 with great reliability, good accuracy, great shot count etc, thanks for this very fine review.

Leave a Comment

Buy With Confidence

  • Free Shipping

    Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

    Free shipping may not be combined with a coupon unless stated otherwise.

    View Shipping Info

  • Shipping Time Frame

    We work hard to get all orders placed by 12 pm EST out the door within 24 hours on weekdays because we know how excited you are to receive your order. Weekends and holiday shipping times will vary.

    During busy holidays, we step our efforts to ship all orders as fast as possible, but you may experience an additional 1-2 day delay before your order ships. This may also happen if you change your order during processing.

    View Shipping Times

  • Shipping Restrictions

    It's important to know that due to state and local laws, there are certain restrictions for various products. It's up to you to research and comply with the laws in your state, county, and city. If you live in a state or city where air guns are treated as firearms you may be able to take advantage of our FFL special program.

    U.S. federal law requires that all airsoft guns are sold with a 1/4-inch blaze orange muzzle or an orange flash hider to avoid the guns being mistaken for firearms.

    View Shipping Restrictions

  • Expert Service and Repair

    Get the most out of your equipment when you work with the expert technicians at Pyramyd AIR. With over 25 years of combined experience, we offer a range of comprehensive in-house services tailored to kickstart your next adventure.

    If you're picking up a new air gun, our team can test and tune the equipment before it leaves the warehouse. We can even set up an optic or other equipment so you can get out shooting without the hassle. For bowhunters, our certified master bow technicians provide services such as assembly, optics zeroing, and full equipment setup, which can maximize the potential of your purchase.

    By leveraging our expertise and precision, we ensure that your equipment is finely tuned to meet your specific needs and get you ready for your outdoor pursuits. So look out for our services when shopping for something new, and let our experts help you get the most from your outdoor adventures.

    View Service Info

  • Warranty Info

    Shop and purchase with confidence knowing that all of our air guns (except airsoft) are protected by a minimum 1-year manufacturer's warranty from the date of purchase unless otherwise noted on the product page.

    A warranty is provided by each manufacturer to ensure that your product is free of defect in both materials and workmanship.

    View Warranty Details

  • Exchanges / Refunds

    Didn't get what you wanted or have a problem? We understand that sometimes things aren't right and our team is serious about resolving these issues quickly. We can often help you fix small to medium issues over the phone or email.

    If you need to return an item please read our return policy.

    Learn About Returns

Get FREE shipping on qualifying orders! Any order $150+ with a shipping address in the contiguous US will receive the option for free ground shipping on items sold & shipped by Pyramyd AIR during checkout. Certain restrictions apply.

Free shipping may not be combined with a coupon unless stated otherwise.

View Shipping Info

Text JOIN to 91256 and get $10 OFF Your Next $50+ Order!

* By providing your number above, you agree to receive recurring autodialed marketing text msgs (e.g. cart reminders) to the mobile number used at opt-in from Pyramyd AIR on 91256. Reply with birthday MM/DD/YYYY to verify legal age of 18+ in order to receive texts. Consent is not a condition of purchase. Msg frequency may vary. Msg & data rates may apply. Reply HELP for help and STOP to cancel. See Terms and Conditions & Privacy Policy.