Home Blog  
Ammo Ruger Mark I pellet pistol: Part 2

Ruger Mark I pellet pistol: Part 2

by B.B. Pelletier

Part 1

The Ruger Mark I pellet pistol is a powerful spring-piston gun.

Several readers indicated an interest in the Ruger Mark I pellet pistol, and we had one warning to watch the plastic frame for cracks. I’ll do that throughout all testing; but I can say that after today’s shooting, everything is still sound.

One reader commented that his pistol was the worst-dieseling airgun he had even seen. He may have said dieseling, but I think he really meant detonating, given what I see with the test gun. The test gun detonated several times at the beginning of testing, then settled down to just a diesel with every shot. But because of the type of oil or grease the factory used, there was a lot of smoke with every shot.

In this respect, the test pistol acts identical to the B-3 underlevers I tested back in the 1990s. It’s grossly over-lubricated at the factory and will continue to smoke and smell like frying bacon for a long time. As a result of this over-oiling, we have to look at the velocities with a certain skepticism.

Once again, I must report that this pistol cocks easily for its power. It’s definitely meant to be used by an adult male, but you should be able to cock and shoot it several hundred times in one session without a problem. The cocking effort with the cocking aid installed measures just 25 lbs. — BUT — you can easily get a much higher number when measuring this pistol. It’s obvious when cocking that the mainspring isn’t lubricated very much, if at all. So, as the gun is cocked the spring crunches and pops as its coils slip into the piston skirt and over the spring guide. When that happens, the scale can go up above 30 lbs. pretty fast. The secret to cocking the gun with the least pressure is to use all the mechanical advantage that’s available and to cock the gun quickly and smoothly. Don’t hesitate during the cocking stroke, or the mainspring will hang up and the effort required will increase.

A proper lubrication of the powerplant with some spacers to take up what feels like excess space around the mainspring would reduce the cocking effort to exactly 25 lbs. each time. I doubt that it will get any lighter than that, even with extensive break-in, as long as this mainspring remains in the gun.

This gun has a heavy two-stage trigger. The trigger is adjustable for the length of the first-stage pull, but the pull weight cannot be adjusted. The advertised pull weight is 5.5 lbs., and my test pistol averaged 6.7 lbs. over 10 pulls. It does feel as though the trigger is breaking in, so that weight may decrease with use.

While this is a heavy trigger, it isn’t too heavy for good shooting. You want a heavier trigger on a handgun to help control the gun. That’s accomplished when the pistol is drawn into the web of your shooting hand by the force of pulling the trigger. This one goes way beyond what’s required for stability, but not so far as to be excessive.

I started by testing the gun with Crosman Premier 7.9-grain domed pellets. The first shot went 409 f.p.s., then the next five were all above 500, with one going 596 f.p.s. Then, the gun calmed down, again, and shot this pellet at an average 456 f.p.s. This string ranged from 451 to 462 f.p.s., and the pellet produced an average 3.65 foot-pounds of muzzle energy.

Next, I tried the RWS Hobby pellet. Although the gun was still smoking on every shot, this time it didn’t seem to detonate as much. It was just dieseling, which is expected, but not detonating.

Hobbys averaged 473 f.p.s. and ranged from 466 to 486 f.p.s. There were no impossible velocities in this string, so I think the gun has calmed down. At the average velocity, this pellet produces an average 3.48 foot-pounds of energy at the muzzle.

The last pellet I tested was the Beeman Kodiak — a heavy .177 pellet that’s out of profile for use in a pistol of this power. Even though it won’t be used, it’s good to see where the boundaries of the gun lie, and the performance of a heavy pellet is one of the things you have to look at.

Kodiaks averaged 360 f.p.s. and ranged from a low of 348 to a high of 366 f.p.s. Like the other two pellets, they’re reasonably consistent. At the average velocity, they averaged 3.05 foot-pounds of muzzle energy.

Umarex advertises this pistol to shoot at two different velocities — 500 f.p.s. shooting lead pellets and 600 f.p.s. shooting high-velocity non-lead pellets. So far, the fastest we’ve seen from lead is one shot at 486 with Hobbys, so I thought that it was important to also test this gun with the high-velocity, lead-free pellets. Shooting 5.2-grain RWS HyperMAX pellets, the pistol averaged 554 f.p.s. with a spread from 542 to 574 f.p.s. That’s an average muzzle energy of 3.54 foot-pounds of muzzle energy.

I wondered whether seating the pellets deep in the breech would affect the outcome, so I shot a second string with the pellets seated deep, using the Air Venturi Pellet Pen and PellSet. These pellets really popped into the breech, so the resistance their skirts provided was significant. Set deep, they averaged 567 f.p.s. with a spread from 562 to 573 f.p.s. That’s an average 3.71 foot-pounds of muzzle energy. So, the average speed increased and the spread tightened, even though the maximum velocity did not change.

I read many reviews of this air pistol — both on the Pyramyd AIR website as well as other places. Some have compared it to the Beeman P1, the RWS LP8 and the Browning 800 Express. Apparently, they think this pistol is in the same power category as those three, but it isn’t.

For what it is, the Ruger Mark I is a consistent spring-piston air pistol that’s relatively easy to cock and produces reasonable power. The shot-to-shot consistency is very good. When taken as a whole, we must also consider the heavy trigger and the accuracy that hasn’t been tested, yet. It’s too soon to make any pronouncement about whether or not this is a good air pistol. It’s certainly very smoky to shoot and does need the cocking aid. But none of that will matter unless it can also group.

One final thought. One customer review I read said the shooter was grouping from five meters. I will test the pistol at 10 meters unless there’s a compelling reason not to. A pellet pistol with a rifled barrel ought to be able to shoot that far with some level of accuracy if it’s to be considered for anything.

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.

30 thoughts on “Ruger Mark I pellet pistol: Part 2”

  1. BB,
    Off topic. I’m learning that 3/8″ dove tail mounts are not the same as 11mm. To make matters worse, some mounts that are available claim to support both by flipping the attachment bar. Using a gas springer, it was effident that a true 11mm mount provides optimal lock, to the point that a stop pin isn’t even required. Another learning lesson.

    • TC,

      I have to disagree. No 11mm scope mount I am acquainted with, other than the BKL mounts that are currently being produced, can hold against the recoil of a powerful spring gun without a positive mechanical lock. I have test this repeatedly over the year. Even the BKLs that were made ten years ago failed my test. You must use a mechanical scope stope if your rifle has much recoil, or those mounts will walk.

      As for the 3/8-inch versus 11mm controversy, the picture is less clear. 11mm is a nominal scope base size. The actual grooves measure anywhere from LESS that 3/8-inch to well over one-half-inch, depending on whose they are. So, for many applications, 3/8-inch and 11mm are essentially the same, or so close that it doesn’t matter.

      When you get specific about the application is when this all starts to matter.


  2. Wouldn’t it be something of manufacturers provided conservative velocities (i.e., with lead pellets), so that customers could be pleasantly surprised by their own results?

  3. B.B.,
    Could you retest and re-report the cocking effort and trigger pull at the end of your accuracy test’s (assuming that’s the last test) so that we can get a sense of how much this gun my actually break in? Thanks!

  4. BB,
    Aren’t 3/8″ dove tails usually cut at 45 degrees, with 11mm usually cut at 60 degrees. If so, it appears that width and angle play a role in optimizing the grip. I haven’t tried the BKL mounts yet, but the design looks awesome. What do you use to keep the scope from sliding once the mount is locked down. Some rings come with a special tape. Is that tape available by itself?

    • Tape/no tape…
      Rings that come with tape are machined larger so that the tape will take up the slack to fit the scope. Remove the tape and the rings are a sloppy fit.
      Switching around….
      If you put tape in rings that were made to fit the scope in the first place, tape will make them awful tight.


      • TwoTalon,
        OK, that makes sense. I had to replace the tape on a UTG ring and decided to use 3M friction tape. So far so good. Looks like the better rings don’t need any friction material because of the tighter fit. Another learning lesson. 🙂

    • TCF,

      When Dan Bechtel, the owner of B-Square, and I sampled 11mm dovetails from around the world (so he could make his AA adjustable mounts) we found no standards. He published a list of the widths we discovered in that sampling. It ranged from just over 9mm to almost 14mm! And we found over 30 uniquely different dovetail styles in the group that was sampled.

      No standardization whatsoever!


      • BB,
        Amazing. With the precision demanded by so many users in this sport you would expect a higher degree of standardization. Thank you for setting me straight. 🙂

  5. B.B.

    A little off the subject, but I know you are a fan of the Makarov pistols. An online dealer I purchase stuff from has a few Bulgarian Makarovs for sale. Good condition other than some finish wear. They are supposed to function fine. My question, since it’s a gun I want the shoot, is how is the trigger pull on most of the Makarovs you fooled around with?


      • Matt61:

        The ammo is not really as exotic as it sounds and is becoming more common albeit mostly through online dealers. In the Commie brands Wolf and Bear can be found a reasonable prices. CCI and a few other US companies manufacture the round. Hornady offers a self defense round. So quite a few ammo options are available, but you are going to have to order either online or mail order. Most local stores are going to have limited options if any at all in my experience.

        As for the round, the 9×18 or 9mm Makarov is somewhere between a .380 and 9×19. So it would not be my first choice for self defense, but with the right ammo it would be an OK round. A lot of folks carry the .380 for self defense. Personally I would prefer a 9×19 or larger caliber firearm with defensive rounds for personal defense. Of course any gun you have when you need it is better than no gun at all. Plus you get into things like shot placement, etc. So yes the 9mm Makarov is somewhat underpowered, but it has been used widely by military and police and I’m sure a number of folks are not breathing today because of it. BTW, if I’m not mistaken the Russians are upgrading to the standard 9×19 handgun round.

        Matt61 my reason for wanting a Makarov is not self defense, but for recreation. Getting to shoot a gun that’s part of Commie history. It’s the gun the bad guys carried in the old spy movies. The cool factor.


  6. What’s the difference between dieseling and detonating? I thought they were the same thing.

    So, Duskwight and Whiscombe owners, why does the opposed springs design cause the rifle to be ruined with a single dry fire? What is double the damage of an ordinary spring piston dry-fire doesn’t clearly equate in my mind with complete destruction.

    Victor, do you own or have you fired a 1911 firearm? Like I said, I have found it to be almost the only firearm where airgun practice did not translate directly because of the recoil. Admittedly, what appears to have put the problem under control is the same old fundamentals–especially following through. But learning to apply the fundamentals to this particular gun took me some time and hands on-practice. By the way, how goes it with the Ruger LCR? I hear great things about it on all hands.


    • Matt,

      Answer this. Which is worse — hitting a brick wall at 50 m.p.h., or hitting an oncoming car that’s also traveling 50 m.p.h.? The answer is the second one, because the closure rate is double.

      Opposed pistols come together like the clapping of hands — twice as bad as just hitting the solid wall of the compression chamber with one piston.


      • There’s a bit more to it than that…

        If the brick wall is essentially immovable, hitting it at 50mph is akin to hitting a car of equal weight and construction that is doing 50 in the opposite direction. Hitting the brick wall is worse than hitting a lighter car, and better than hitting a heavy one.

        Certainly, a 2-car collision involves twice the kinetic energy. But it also involves twice the car crumpling that dissipates that energy. Likewise, from a momentum standpoint, both situations cause the car to stop completely right where the impact occurs.

        • So it would be more accurate to say “which is worst hiting a brick wall driving 50mph or hitting a brick wall that’s coming at you at 50mph while you’re also going 50mph in the opposite direction”?

          It’s a shame we can’t post pics in here, I turned my 1701P into a mini carbine with a wood stock I had made for me and the guy who did the work is an artist, the thing is gorgeous (oh and it also shoots VERY well, and it’s easy to fill with a pump!).


    • Dieseling and detonation….

      Burning flammable material in a fairly controlled manner. Works just like a diesel engine. Same as a gas engine, but with a different ignition source.

      The whole works burns at almost the same instant. An explosion.
      Just like “engine knock” or “engine ping”. Beats the crap out of engines. Not good for airguns either.


    • Matt61,

      I don’t own a 1911, but used to shoot them back in my competition days. My coach, Stan Hulstrom, was at one time the best “hard ball” shooter in the country (you’ll see his name in the NRA’s hall of fame at Camp Perry) and insisted that a .45 caliber could be shot almost (if not equal) to a .22, provided the pistol was “accurized”. The fundamentals are the same. What seems to affect performance is the “flinch factor” (i.e., anticipation of recoil). Again, the way to solve the problem of anticipation is to strengthen your “follow-through”.

      Good shooting requires lots of practice, even if you know everything that you should. Knowledge alone does not translate into great shooting. You need to shoot so much that all of the fundamentals become second nature. Follow-through is SO CRITICAL! I personally can’t know what I’m doing wrong unless I follow-through faithfully.

      THE GOAL
      Again, according to Stan, “the goal is to get the hammer to fall such that your sight alignment is not disturbed”. This one simple goal is what it’s all about, no matter what you are shooting. Grip, trigger squeeze, “natural point of aim”, and “follow-through”, are the fundamentals needed to achieve “The Goal”. But perfecting each of these fundamentals are challenges in themselves. Once you do though, you can more purely focus on “The Goal”.


  7. I got one of these guns in a trade. At 700 fps (going on what’s the listed fps on pyramyd air’s sale section) I thought it was a bit hard to cock. I’m glad it comes with a cocking assist tube but beware with that thing. I found out the hard way it has to be all the way on or you just might lose a bit of skin on your knuckles when it slips. Powerful for an air pistol . I just think the effort to cock it and fire it is a bit too much. Anybody want a very lightly used ruger mark 1?

    But I am a bit spoiled by my converted to pcp 2240 that spits .22 caliber rounds at 900 fps. I tried for 1000 like the evanix hunting master but 900 fps was all I could get. Still, that’s enough for some squirrel hunting if you can get the things to stand still enough to get them in your sights.

  8. I just got back from the range, where my grandson Nicky out shot me with my Bronco Target Gun.

    This was at 25 yards.

    This follows a day last summer where my granddaughter Ceriah out shot me with my scoped Daisy 856.

    Also at 25 yards.

    I don’t know if I’m bragging or complaining. It does seem the guns are doing their job.


  9. BB,thanks for the link for the old PA site(i felt like i got a cheat code for a video game ha ha) I think i might of bought the last HW80 25 carbine last night.the listing said limited quanity and the 22 carbine was not listed anymore.Ill keep on checkin the PA web site once a week,to see if they bring back the 20cal HW80 carbine or the 20 cal HW90. I know that PA always offer sellect or limited production guns.Did you check out Diana web site they offer beautiful stocks for some of their springers.I wish PA could get the stocks here in USA for us.I would buy the whole guns again .

  10. In regards to scopes, or red dot sights moving on a springer pistol, I’ve found a solution for my Browning 800 Express. Initially the recoil would move the red dot so far to the back of the dovetail that it stripped the threads of the rear bolt holding the red dot. I bought a pair of 6-32 thread hex head bolts with a pair of aircraft nuts (those with the plastic inserts), and installed them on the red dot. After several shots, I re-tightened the nuts. Since, I’ve shot the pistol many times without any movement of the sights. I’ve had no such problem with my Diana LP-8. RC

  11. Hello! I hope I am in the right section as I have a few questions about this guns customization capabilities. First off, does anyone know how many MM’s the barrel is? I have realized that most muzzle brakes need the OD and ID of your barrel and I cannot find this specification for this gun anywhere. I really want to add a muzzle brake in order to not use the cocking assist. Please could anyone give me a link to a 2 inch to 3 inch muzzle brake? It would make this pistol that much better. thank you!!

    • Jordan,

      Welcome to the blog.

      I think you meant to ask about the outside diameter of the barrel. When you ask how many millimeters a barrel is, the most common meaning is the barrel’s length.

      I don’t know the answer and I no longer have the pistol to be able to measure it. This report was written 3 years ago.

      I think if you were to call Pyramyd AIR, their technical department might be able to help you. 888-262-4867

      You are going to have to do a lot of machining to fit a muzzle brake to this pistol, because the front sight base must be taken into account. It may not be worth the effort for such an inexpensive pistol.


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.