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Ammo Quackenbush .25 pistol: Part 2

Quackenbush .25 pistol: Part 2

by B.B. Pelletier

Part 1

Test data and photos by Earl “Mac” McDonald

Nobody played!
First of all, we got no answers on last Friday’s question at the bottom of the blog. The answer is: it’s a catapult gun, and it shoots steel BBs. It was offered by the same company that built the Johnson semiautomatic rifle that was used as an alternative by the Marines in World War II, but at the price of $15 in 1948, it never stood a chance.

Today, we’ll shoot the Quackenbush .25 pistol for velocity and accuracy. There was a surprising amount of interest in this pistol, though much of the talk took place on Pyramyd Air’s social network sites. But even here, many readers know about this airgun. Just as a reminder, this isn’t a fire-breathing PCP. It’s a CO2 gun that uses the same stock valve as a Crosman 2240.

This pistol bloops them out at less than 400 f.p.s. because it’s a .25 and shooting pellets far heavier than the valve was designed to handle. Mac says he loves watching them arc out through the scope and drop through the aim point at the last instant. When the sun is behind you, it can be quite a show.

We’ll start with the velocity first. A couple of readers guessed that this pistol would shoot under 400 f.p.s. and they were right. The fastest average velocity Mac recorded came from Diana Magnum pellets — an obsolete brand that used to be the best .25 caliber pellet on the market. Until now, Mac has found that it shot best in this pistol. Although Diana Magnums came in both 20- and 21-grain weights (they varied over time), Mac says these weigh an average 19.90 grains, so these are the lighter ones.

Because this is a CO2 gun, Mac had to allow for cooling — so he waited 15 seconds between each shot. That allows the gun to warm up. He also replaced the CO2 cartridge after 24 shots, even though he says the gun gets up to 40 shots per cartridge. That gave every pellet the best chance to perform.

Mac recorded an average 378 f.p.s. with this pellet. The total spread was 7 f.p.s., which is pretty tight for such an inexpensive airgun . At the average velocity, this pellet generates an average 6.32 foot-pounds of energy at the muzzle. Because this is a gas gun, it’s probably going to get more energy from heavier pellets.

Next up was the Beeman H&N Match wadcutter pellet. Weighing 21.6 grains, they averaged 370 f.p.s., with just a three foot-second spread. The muzzle energy was 6.57 foot-pounds.

Mac upped the ante with one of the two new .25-caliber pellets. The Benjamin dome weighs 27.8 grains, so it’s a heavier pellet in this caliber. It averaged 323 f.p.s. with a 7 f.p.s. total spread. The muzzle energy was 6.44 foot-pounds, so less than you would predict; but because it’s a Benjamin pellet, there’s antimony in the alloy, and that may slow it down just a little.

I told Mac that this pellet and the next one are the two most accurate .25-caliber pellets on the market. I expected both of them to beat the Diana Magnum in his pistol.

The final pellet he tried was the new JSB Exact Kings that weigh 25.4 grains. This is the other very accurate pellet that Mac tested. It averaged 346 f.p.s. and generated an average 6.75 foot-pounds. The total velocity spread was 9 f.p.s.

Okay, now the velocity testing is out of the way, and what do we have? The pistol averages under 400 f.p.s. but over 6 foot-pounds of energy. So, it isn’t a weak air pistol. Slow, perhaps, but not weak. So, how does it shoot?

Accuracy testing
Mac shot the pistol at 25 yards. I asked him to shoot 10-shot groups instead of the five he used to shoot with this gun. That made a difference in the group sizes, of course. But another dynamic emerged during testing that I think you’ll find very interesting. I’ll explain it as we go.

Ten shots at 25 yards. Believe it or not, the first four shots are all strung apart from the main group, where the last six shots went. Group measures 2.16 inches between centers.

Do you see the dynamic? The group forms around the final shots. Mac did “season” the bore between targets with two shots from each new pellet; but, even so, the pellets walked into the group at the end of each 10-shot string. I suggested to Mac that this might be due to seasoning the barrel, but he thought it was because the gun cooling down as it was shot.

The heavy JSB Exact Kings were next up. Mac found them to also string vertically for the first three shots, then bunch together at the end, just like before.

Ten JSB Exact King domed pellets made this 1.09-inch group at 25 yards. The first three shots are vertical, then the final seven are bunched together below. There’s one straggler out to the right, but this is a much better group than the wadcutters produced.

Thus far we have seen an interesting dynamic of the pellets moving to a place, then grouping tightly. So how do the formerly most accurate Diana Magnums react? They’re next.

The Diana Magnum pellets didn’t act like the first two pellets. They all landed at the same height on target, without an vertical stringing. Group size was 1.09 inches between centers.

The Diana Magnums don’t seem to follow the same pattern as the first two pellets. I don’t know why that would be, but that’s what the target shows. As with all other pellets, Mac seasoned the bore with two shots before this group was fired. Let’s go to the final pellet and see what happens.

The Benjamin domes gave the smallest group of ten shots at 25 yards. Group measures 0.85 inches between centers. Again, we see a vertical orientation to the group; though, this time, Mac didn’t indicate that the final shots were all bunched together in the large hole.

The results
There you have it. That’s what this Quackenbush .25 can do.

In my opinion, Mac should pick just one pellet — the Benjamin dome — and shoot nothing else in this gun. I think the tighter groups at the end are due to seasoning the bore; because in my other testing, I’m starting to see very similar results. But even if that isn’t what’s happening here, the Benjamin dome is still the accuracy champ.

Is the Quackenbush conversion a good thing for a Crosman 2240? If you want a .25-caliber air pistol and you don’t want to get into high-pressure air, then I guess it is. You must accept the low velocity, while realizing that this pistol is still a good deal more powerful than a Beeman P1. And because it’s launching very heavy pellets, it retains more of that energy longer downrange, so things keep getting better the farther the target is from the muzzle — within reason.

This much is certain — people love tinkering with their Crosman airguns, and Dennis Quackenbush has provided the means to do that for over a decade and a half. This may not be the only game in town, but it’s certainly one of the very best.

The Quackenbush .25-caliber conversion is a neat way to customize your Crosman 2240.

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.

35 thoughts on “Quackenbush .25 pistol: Part 2”

  1. .25 cal. pistol blooping them out! Interesting!
    I fitted the .22 barrel to my Beeman RS-2 recently. It was the first time I shot anything bigger than a .177 from an airgun. I don’t have a chrony, but I could tell it was shooting the 14.7gr. pellets slower than the 7.9gr. .177’s.
    It didn’t have an adverse effect on its accuracy. Using the scoring system I have been using for all my guns, this .22 shot my best score yet: 288 out of a possible 300.
    I got some Crossman CP hollowpoints for it from Pyramyd AIR. With the “four for three” pricing, the pellets cost me half of what they do here in town, even when counting the shipping! I ordered them last Monday, and got them Friday of the same week!

    I bought a new gun last Saturday, and am looking forward to evaluating it. I wasn’t planning to buy this particular gun, but was planning to buy a gun. Here is what happened.

    One of the fellows I have been dealing with since moving to Nebraska in 2003 runs a combination gun/hobby shop in North Platte. I have bought everything from a Winchester 600X to N-scale locomotives, to model ship kits, to .45/70 ammunition from him. I found out this month he was not going to be re-newing his FFL this year, and wanted to sell off his entire gun inventory by June 30.

    When I got to his shop, I was happy to see that about 90% of his gun inventory had been sold. The gun owners in North Platte were really getting behind this guy, trying to help him out. He had all his guns marked way down. I would have bought a powder-burning concealed carry auto pistol if I could have afforded it.

    Now, air guns were not subject to FFL, but they were part of his inventory. He had two lying on his counter in sealed boxes. One was a Benji Sheridan, not what I’m interested in. The other was a Winchester 1000WS.
    I wasn’t very impressed with the 600X, but decided to have a look at the 1000WS. I was pleasantly surprised when I opened the box. This was a much bigger gun than the 600X, and had a handsome wood stock with nice checkering. It also included an A.O. scope. It was in .177 cal.
    So I bought it. Today I decided to try cleaning the bore before shooting it. I cleaned it with JB Non-embedding bore paste, followed by patches with Pellgunoil, followed by dry patches. Wiped it down with a Hoppe’s No. 7 silicone-impregnated rag. Mounted the scope and adjusted it for cant, set the A.O. for 25 yards. Now, we will see how it shoots.

    When I go to the range this week, I want to take my granddaughter Melanie with me. She is recovering from a bicycle accident she had two weeks ago. She borrowed her friend’s bicycle to discover the brakes didn’t work. She T-boned a car and put her head through the driver’s door glass.
    Fractured her skull, broke both cheekbones, broke her collar bone, and got a concussion. Over $1600 damage to the car. Also injured the driver. This with a bicycle!

    Anyway, she got titanium patch plates below each eye. She is off her pain medicine now, but I don’t want her to shoot a rifle because the recoil into her cheek would not be good. But, she wants to shoot, so I’ll let her shoot my Daisy 15XT. She was a top competitor in her bb gun class last winter, and should keep shooting in the off season with her brother Nicky.

    I gave Nicky a scoped Crosman 760 this year, and their mother gave Melanie one also. Their younger sister Amber is going into the shooting program this year, and I think my daughter is giving her a pink Red Ryder. I took Amber to the range with me last week.

    If I leave nothing else behind, I will leave grandchildren who can shoot!


      • What surprises me is the speed she is recovering. She was coming down Boot Hill (the location of the original Boot Hill Cemetery in this former “Hell on Wheels” town. It is the second bad bicycle-car accident at that intersection in recent years.

        This accident could easily have killed her, and probably would have killed an adult. She is eleven.

        She is here right now, waiting to go to the range.


    • Desertdweller,

      So glad to hear that your granddaughter is recovering nicely. You are truly blessed and I know that there a lot of folks here that are praying for her speedy recovery. Congratulations on having a bunch of shooting grandchildren.


      • Thank you. She shot pretty well today, considering her right collar bone is broken and she is right-handed. I put four small Shoot-n-C targets on a carpet steamer box at about ten feet. She drilled the targets pretty good. Shot about a hundred Crosman Copperhead bb’s, 2 CO2 cylinders of gas.

        Not too bad for someone who had her head screwed back together the weekend before last.


  2. Hi, i am from south africa. I have two airguns in my possession that i would like to know if you could perhaps give me more info on. They belonged to a family friend’s grandfather (they are Jewish). She immigrated to australia and couldnt take them with her, so she gave them to us. The first: gerstenberger & Co, original EM-GE, made in germany, B1961. The second: Röhm RG 2. I know absolutely nothing about airguns. Can you maybe help?

    • jeannie,

      You don’t mention whether either of these airguns is a rifle or a pistol, but I will assume that you have an EM GE Zenit — a well-built spring-piston air pistol. It cocks by pulling the strap the rear sight is attached to up and forward. The breech is then exposed to load. In the U.S. this is a desirable air pistol. I’m going to guess that it is a 4.5mm or .177 caliber.

      The Roehm RG2 will be harder for me because they didn’t make airguns. They were a distributor that sold other people’s models under their own name, and I don’t have any good way of researching them. They are no owned by Umarex of Germany.


  3. Hang in there jeannie! I just copied your post above to the experts at the Vintage airgun board and asked them to address your questions. Like the older guns we admire we’re often a bit slow so response may be the same. Tom

  4. BB,
    Interesting phenomenon with those shot strings. But the pistol settles down really nice. Looks pretty good to me for a pistol – at 25yds no less. I wonder if the final 6 would hold if he immediately followed up with another 10 shot group on a new target? Or fired four shots off target before starting a 10 shot group?

    Also, with all this demand you’ve been putting on Mac couldn’t you have at least loaned him a dime?


  5. I never got to read the weekend blog until yesterday.I read it right after I got home from being hit in the driver door of my car by a sedan doing 40mph.I knew the answer……however I just assumed it had been answered correctly given that it WAS sunday afternoon! I only knew the answer because you wrote about it years ago.The question even suggested an uncommon powerplant due to it’s wording.
    Oh well,that is my luck here lately…..yesterday as I fished my license out for the responding officer I noticed I was carrying 6 raffle tickets for a new car(and the drawing was happening right then!)
    Mac did remarkably well at 25 yds. with a stock 2240 trigger! The best replacement trigger is a stainless Cothran IMHO it has roller bearing and a nice wide blade that reduces the percieved pull weight.I wish I had 6 more of them for my Outlaw pistols/carbines.
    The 2240 mods are a Genie that stays out once released from the bottle! I can’t help picturing that pistol on HPA with a Discovery valve,or a Hipac unit after securing the valve with 6-32 screws for safety.Or a Boss valve,longer tube and a bulk fill like a Crosman 111 or 112 (or 115/116).Then it would need a carbine stock,or an adapter for a Tippman collapsable buttstock.The possibilities are literally
    endless. I haven’t even mentioned a riser or spacer for the breech to allow for a barrel shroud,or a set of beautiful target grips.I think building a 2240 to suit you is a rite of passage for many contemporary airgunners!

  6. Thank you so much for your speedy reply, B.B! I found out about half an hour ago that they are, in fact, both vintage starter pistols. It’s a pity i could’nt post a photo of them in my first post. Now that i know what they are, i can sell them as such. Thank you, Tom, for giving my post an extra boost!! Very kind of you

  7. Here is my evaluation of the Daisy/Winchester 1000WS.

    Went to the range this morning with my granddaughter Melanie. While she shot my Daisy 15XT, I tried out my Winchester 1000WS.

    This gun is very different than the Daisy/Winchester 600X. The 600X is more of a carbine, or saddle gun. It is a lot lighter, and has a hardwood stock with horizontal grooves on the forestock. It is made in Turkey.

    I mounted a Tasco 4-9x50mm scope on the 600X. High Leupold scope rings were needed to get that big objective lens clear of the action.

    The 1000WS included an adjustable-objective 32mm scope. It is bright and clear. Both the scope and the gun are made in China.

    I was impressed with the finish of the 1000. It has a hardwood stock with checkering on both the forestock and the pistol grip. All visible wood surfaces are free of flaws.

    Open sights are the now-common fiber-optic. The rear notch sight is adjustable both up and down and sideways.

    Before shooting the 1000, I cleaned the bore with JB non-embedding bore paste and Pellgunoil. I managed to scratch the bluing slightly with the cleaning rod at the receiver behind the transfer port.

    I was shooting a 6″ Shoot-n-C target at 25 yards. There was a 15-20 wind gusting from behind me. Temperature was in the mid-70’s.

    The gun did not noticeably Diesel. No loud cracks, no smoke. i was shooting 7.9gr. Cabela’s wadcutter .177 pellets. At 25 yards, I could not get on the paper. I had to adjust the scope!

    I moved the target up to about twenty-five feet. Increased elevation and got it to hit right. Moved the target back to 50 feet. Dialed in some left windage. When I was satisfied, I put the target back at 25 yards and set the objective accordingly.

    This gun behaved well when firing. No hard shock or recoil, no buzz or weird vibration. It did not try to break the scope.

    It is a heavy gun to hold on target, but that is something I personally prefer.

    The major fault I find with this gun is its heavy, creepy trigger. The 600X was bad for this too, but I think the 1000 is worse. Pyramyd AIR measures this trigger as breaking at 9 pounds! There is a long, creepy first stage, then you really have to squeeze to get the shot off. I am hoping this will get better with use, I hesitate to tear anything like this apart because I may make it worse.

    This is really “culture shock” after shooting the Bronco, with its 30oz. trigger.

    I shot one thirty-round target with this gun. My score was 265 out of a possible 300. For comparison, my best score ever was 288 with my .22 RS-2, 285 with my Crosman Storm XT, 279 with my target model Bronco. My Bronco is the only gun without a scope, uses a Mendoza peep sight.

    Other than the heavy trigger, I think this is a pretty nice gun. With a lighter trigger, it could be outstanding.


  8. Off topic…

    Does anyone here have any experience with the GAMO Blue Flame or Red Fire .177 Caliber Pellets?

    If so I’d like to know if you like them.

    Thanks, Gang


    • JoeB,
      I saw them at Walmart and they were so pretty (the packaging), I wanted to buy them in spite of having no need and knowing better. I resisted the urge, but I’m curious, also.

    • Gamo redfire is an unlicensed copy of the Predator PolyMag. There is a lawsuit against gamo, and they are using deep corporate pockets to stick it to Predator (a small almost 1 man operation)
      Since finding out, I have not bought a single gamo product. Besides, from what I’ve read, the red fire (and all the other colors they used in their stolen design) aren’t very accurate.

  9. Les, how did Melanie do with your Daisy 15XT? I had one years ago but sold it because the trigger pull was too hard.

    I’ve lit a candle for your granddaughter’s recovery.


    • Thanks, Joe

      She didn’t do badly at all. I wish I had my PPK working, it is a much better pistol.

      The 15XT has a ridiculous trigger pull. While she was fighting that, I was fighting the trigger on the 1000WS.


  10. Hi BB,
    I understand that Quakenbush no longer make 25 calibre guns because he found out that the loading mechanism of high power of his guns would damage the pellet skirts thereby ruining accuracy. Any truth in that?

    • Ton,

      Great to see you posting.

      Interesting question. Don’t know about Mr. Dennis Quackenbush discontinuing his .25 caliber guns because the (his?) loading mechanism damaged pellet skirts.

      After looking at the targets I don’t think we’re witnessing skirt damage. The targets were shot at 25 yards with a pistol and we’re seeing a 10 shot group that is 0.85 inches ctc!!! The scope is an old simmons 4X that was reparallaxed to 25 yards. Personally I think parallax contributed to the vertical stringing but those spectacular groups at 25 yards with a cheap rimfire scope that was reparallaxed are phenomenal and don’t indicate any skirt damage during loading to my eyes. Just my opinion.


      • I have four .25 Quackenbush airguns…..a rifle (Knave),a carbine rifle,a Outlaw pistol and a pistol like this,but with a Walter Glover built tube running Disco valve.None of them have apparently heard this rumor.
        My understanding,aside from personal observation is based on his notes…..just a google search away.
        If you search Quackenbush Knave and click on his website,he tells of shooting at 1000 fps causing decreased accuracy (below minuite of angle).He was simultaneously developing the .308….and it had no such limitation.He notes that either detuning to under 900fps OR shooting cast ammo solves the problem.
        He proposed that the higher velocity set up was deforming the pellet or disturbing it from the air blast…..not the breech.

        • Frank B,

          Good information. Thanks.

          I don’t own and have never owned a Quackenbush gun. Blush.

          Help me understand. Since we’re talking about the Quackenbush modded Crosman 2240 that Dennis Quackenbush was famous for does the pellet deformation apply?

          To put a finer point on my question, since the .25 caliber 2240 mod is running around 7fpe does this air blast that apparently/allegedly? affects higher velocity guns apply to this modded 2240?

          On another note…..Since you have 4 Quackenbush .25 calibers which is the most accurate at 50 yards?


          • OK,here it is with a fine point……only the Knave ran into this issue: AND only above 1000fps IF using diablo shaped pellets.So no way would any 2240 suffer this symptom.Sorry if I’m a little hypervigilant
            regarding the facts here…but ALL of this started with Dennis observing what we all know.Pellets suffer when propelled into the trans-sonic region of velocity.
            Lloyd is currently in posession of my Knave,for his study & enjoyment.I asked him to make a hammerspring preload adjuster (so I can retain the ability to shoot cast ammo at the highest velocity
            possible) and be able to stack JSB Kings at 930-950 too.
            My carbine has no trouble making 1/2″ groups at 50yds…..even with a 4x scope! It shoots in the 930-950fps range w/ Kings.It also shoots the Air venturi 61gr (very hard cast) @680fps….I’m trying to ration them,as no more are available.Since I have to go somewhere to safely shoot them,and have too many also…..my conclusions are limited to the above findings.
            I will give more results as I discover them.My only dissapointment is having recieved used DAQs that leaked.This is from unexperienced shooters rushing the fill process…..and cooking the O-rings.Dennis is great about supporting his airguns though.

    • Ton,

      I don’t know whether Dennis has stopped making .25 caliber gun parts or not. His web site says they are still available. And Dennis never told me there was a problem with them, but he doesn’t tell me everything.


  11. “loves watching them arc out through the scope and drop through the aim point at the last instant”.

    I loved this about archery in college, especially at 75 yards and beyond. Great for testing your follow-though!

  12. Thanks all for your replys. I hope no one is thinking I am critical about Mr. Quackenbush!! I would love to own one of his guns – a .25 particularly. It’s been a while since I have posted. I do read though.

  13. I have a 2240 with the .25 Mountain Air top end kit . It has a 12” Walther barrel and their custom valve. The valve allows me to fire 21.6 gr. Silver Ace pellets at 520 fps . It was about 80 degrees when I checked on the chrony. I also tried a Boss Valve from Crooked Barn and got about the same power. This gun is far more fun with the high volume valves. I get 15-16 full power shots before changing the co2 cartridge. If you have a .25 barrel on a 2240, you need a custom valve so the pellet does not arc so much. It is a little over 12 ft/lbs at the muzzle, so you can use on small game at closer ranges.

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