Home Blog  
Ammo RWS Diana 45: Part 3

RWS Diana 45: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

Part 1
Part 2

Diana 45 left
Diana 45 is a large breakbarrel spring rifle.

This report covers:

• Repairs first
• Accuracy test parameters
• Premier lite pellets
• Air Arms Falcon pellets
• RWS Superdome pellets
• More pellets?
• How the rifle behaved
• Next

Today, we’ll begin to learn about the accuracy of the Diana 45 we’re testing. This rifle belongs to a friend of mine, and I want you to remember that the ultimate goal of this series is to completely tune this vintage air rifle to remove as much of the vibration as possible. We aren’t looking for greater power. We want smooth operation. What we’re doing today is just baseline testing.

Repairs first
Before I shot the rifle, it was necessary to address a problem with the sights. The front sight was loose in its dovetails and could not be tightened with the screw. Loose sights do not make for good accuracy, so that had to be addressed before the test began.

Diana 45  front sight
This photo clearly shows the dovetail grooves that are swaged into the barrel near the muzzle. The legs of the sight were squashed together to clamp in these grooves firmly.

I removed the sight, a globe unit with replaceable inserts, that’s held on the rifle by a sheet metal clamp at its base. The clamp legs slide into twin dovetails that are swaged into the end of the barrel. When these grooves are swaged in, the metal around them distorts and constricts the muzzle a tiny bit. That’s the source of the choke that can be felt near the muzzle of these rifles. They’re not intentionally choked, though some people refuse to believe that.

With the sight off, I installed the base clamp in a vise and tightened the jaws a bit, then I struck the vise with a 2-lb. hammer. That impact sends a shock wave through the metal, distorting it to a new tighter dimension. Sure enough, I had to drive the sight back onto the barrel grooves with a plastic mallet. The front sight is now rock-solid, and I should be able to get better accuracy.

Accuracy test parameters
Since I don’t know this airgun, this first test is conducted at 10 meters. Given the open sights, I’m pretty certain it’ll be on paper at that distance. Once the accuracy is confirmed, I can mount a scope and back up to 25 yards for a more thorough test.

I shot off a bag rest and used the classic artillery hold that was designed for spring-piston air rifles like this one. The front sight element is a tapered post, which matches perfectly with the rear v-notch that’s selected from the 4 notches that are available.

Premier lite pellets
The first pellet I shot was the Crosman 7.9-grain Premier — the one we call the Premier lite. Ten of them went into a group that measures 0.491 inches between centers. That’s not bad for a sporting rifle using open sights at 10 meters.

Diana 45  Premier lite 10 meters
Ten pellets in 0.491 inches isn’t too bad. These are Premier lites.

Air Arms Falcon pellets
Next, I shot 10 Air Arms Falcon domes that went into 0.546 inches at the same 10 meters. This pellet loaded easily, in spite of a head diameter of 4.52mm.

Diana 45  Falcon 10 meters
Ten Air Arms Falcons went into 0.546 inches. That’s also okay, though the group is more vertical than I would like.

RWS Superdome pellets
Next up was the pellet that I thought might steal the day. Usually Diana guns do their best with RWS pellets, and the RWS Superdome is at the top of the list. However, these pellets scattered a bit more than I expected. While this group is rounder than the first 2, it’s also larger, at 0.686 inches between centers. It might not be the best pellet for this rifle.

Diana 45  RWS Superdome 10 meters
Ten RWS Superdomes made this 0.686-inch group at 10 meters. While it’s rounder than the first 2 groups, it’s also larger.

More pellets?
With 3 groups in the bag, I could have been finished with this test. Just for fun, I shot 2 more pellets. However, I didn’t waste time on either of them. When I want to test pellets quickly I shoot 5-shot groups and only go on to 10 shots if the first 5 are sufficiently tight.

The first pellet I shot was the H&N Baracuda Match pellet with the 4.50mm head. After 5 shots, I looked through the spotting scope and saw that this wasn’t a pellet for the 45. It measures 0.493 inches between centers, which is as large as the first group of 10 I shot with the Premier lites. Shooting another 5 shots is not going to make this group any smaller, so it was time to move on.

I’ll admit that I’m on the fence with this pellet. I was using open sights, and it might tighten up if I used a scope. I just don’t know.

Diana 45  Baracuda Match 10 meters
Five H&N Baracuda Match pellets with 4.50mm heads made this 0.493-inch group at 10 meters. Shooting another 5 pellets is not going to make this group any smaller, so this pellet is out — maybe.

Lastly, I tried 5 H&N Baracuda Match pellets with the 4.53mm heads. These landed in 2 separate groups at 10 meters The total group size measures 0.562 inches between centers, so this pellet also isn’t one for the 45.

Diana 45  Baracuda match 453 10 meters
Five H&N Baracuda Match pellets with 4.53mm heads made this 0.562-inch group at 10 meters. This is actually 2 separate groups, demonstrating that this is also not a pellet for this rifle.

How the rifle behaved
I’m tuning this rifle because it buzzes when shot, and that came through during this test. It isn’t the worst rifle I’ve tested, but it does have that characteristic 1970’s buzz of a spring-gun powerplant.

The trigger is adjusted very nicely. There are 2 distinct stages, and stage 2 breaks crisply. It breaks at over 3 lbs., but I don’t find that to be a problem.

The recoil (a separate issue from the buzzing) is actually quite low. I think that has a lot to do with the rifle’s short piston stroke.

The rifle cocks smoothly and relatively easily. A short-stroke piston needs a heavier mainspring to generate the same power as a longer-stroke gun, but this one isn’t so bad.

Next comes the 25-yard accuracy test, which will be a completion of baseline testing. After that, I’ll know what this rifle can do before being tuned.

After the 25-yard accuracy test, I’ll disassemble the rifle and do what I can to eliminate the vibration. That means eliminating as much slop as possible between all the parts. I’m lucky that the owner of the rifle is a machinist, because I plan on giving him the parts I want modified or rebuilt.

I’ll take pictures throughout the process, so you can follow along. I know several of you are waiting to see how this rifle comes apart so you can work on your own guns. I promise to take pictures with that in mind.

Stay tuned — this will get interesting!

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.

108 thoughts on “RWS Diana 45: Part 3”

  1. I believe this will be a interesting journey on this gun.

    A 25 yard base line and then onto the tuning. Or buzz eliminating.

    The machined parts of course grabs my attention. This will be a interesting one for sure.

  2. I noticed that Diana do not give you any inserts for the interchangeable front sight globe with new gun purchases. The Weihrauch ones that come with interchangeable front sight do not fit correctly.

  3. Tom, a completely unrelated question if I may. I remember you talking about a new pump from crosman a while back. I see on their website they have an article or advertisement for the new pump, but it doesn’t seem to be listed in their products for sale, and PA doesn’t seem to be selling it. I want to buy a marauder soon, and the crosman pump currently seems to have less than stellar reviews. Any ideas when it might be coming out, or when PA will be selling it?

    Also, long term, I’d like to buy one of the air force line, probably a condor. Would I be best off buying a crosman pump and then an adaptor for the condor? The air force pump now and an adaptor for the marauder? A hill pump and whatever adaptors might be needed?

    Have you ever done reviews comparing the different hand pumps? Do I just need to keep reading back in your earlier articles?

    • Tim,

      If you are going to commence a journey into the world of PCP, I would recommend that you buy a Hill pump. If you use a hand pump on a regular basis, you will end up with one anyway as they are the best built ones there are. No other pump carries a lifetime warranty. No other pump is made to be rebuilt by the owner.

      I cannot vouch for how well the Crosman pump works, but if I am not mistaken they are built by the same people who build the AirForce pump that I do have and the Hill is a much better quality built and functioning pump. The difference is incredible.

      Whatever pump you decide to invest in, make sure you have a female foster fitting on the end of the hose. That will connect directly to a Marauder, Discovery and the AirForce line with the Spin Loc feature. AirForce makes an adapter for the older tanks with a male foster end. You can always adapt the other proprietary fill fittings to foster fittings and they make for quick connection and change out.

      Many who shoot PCP a lot end up with tanks and compressors and such, but just about every one of them also has a hand pump sitting off to the side. With proper care, a Hill will give you last you forever.

      That is just my humble opinion. 😉

      • I’m hoping, long term, to eventually get into big bore air guns as well. I’m eventually going to want to get a tank and possibly some sort of compressor as well, but I know full well that I’m going to get impatient and decide to buy a recluse or a 9mm rainstorm or something before I have the money for a tan/compressor. I guess I’d better just get the better pump now.

        It sucks though, since PA has the bundle and save deals, not only would I be buying a more expensive pump, I’d be losing the bundle, which means I’m going up over 200 dollars if I get the Hill rather than the Crosman pump. I guess it’s time to sweet talk some PA sales person into some sort of discount. 🙂

        Really, though, it’ll be a little while anyway. I’m going to try to wait until they run a sale for 10 percent off plus free shipping, not sure how often those run, but I’ll try to be patient.

        • You will not go wrong with a Hill pump.

          When you do get into big bore, you will find you will almost have to have a tank and/or compressor to feed those things. They such down a lot of air per shot. Myself, when I finally add a big bore to my collection, I will probably just keep on pumping. If nothing else, it is good exercise. 😉

    • Tim,

      The Crosman pump has been in development for 4 years. I announced it several years as part of my SHOT Show reports, and then it never materialized. I’m holding off now until I actually see and test this pump.

      My favorite hand pump has been the Hill for the past decade. It had more quality going for it, though the other pumps do work fine.

      Perhaps it is time for me to revisit hand pumps. I will look into it.


      • B.B., please do. Their are lots of people out there like me that has never had a PCP. I’ve got C02, spring piston and pumps. I’m curious as PCP keeps growing and seems to have more guns than ever offered now. That, plus, with these “cheap” entry level PCP that are out and some coming (maybe Crosman), I’d really like to see something on the different hand pumps. I see PA sells four different brands now. So Thank You for considering testing/reviewing them. Also, if you ever do test or review them, maybe get some young lad for the grunt work as that would be a lot of pumping.

    • Tim,

      The only thing to keep in mind is that with the Crosman pump ate least you need to be in very good shape and/or weigh close to 200 lbs. to pump a rifle to 3000 psi. I can’t do it but admittedly I am not in the best of health and I weigh 175 lbs. I have no idea if the Hill pump is easier to use.


      • I’m big enough to handle pumping. I could use the exercise as well. I broke my arm last year and the elbow never healed properly, now I can’t straighten my arm out completely, so that could make it a little bit harder for me. I can get pretty close to straight though, and I’m strong enough that I think I’ll be able to manage it ok. If not, it will be a good way to strengthen that arm. I need to do something with it, since that’s my left arm, and at the moment I can’t hold my bow while drawing it back with my right hand. I’d like to shoot my bow again. Heck, maybe getting into PCPs will help with that. 😛

            • Tim
              I think we know the answer.

              But it sure would be another excuse to go shoot.

              I can just hear that now. My wife would say to me are you going out to shoot again!

              I would say. But remember what the doctor said. To keep shooting my airgun and to make sure to use the hand pump. 🙂

        • Tim

          In your situation then you may prefer the Hill Pump.I have one and that’s why I find it hard to understand what all the whimpering about pumping is from.I really think they are an advantage.I never pumped guns up more than 5 times in a day though either.

          I want to share an idea I hope will be of use to pumpers.–Take a small straight sided pill bottle with a locking cover and drill a hole in the cover near the edge,but not too close.The hole should be the size of the shaft of the pump hose so the threads will cut into it for a tight fit.Take the fitting off the end of the hose.Screw the hose in through the top of the cover,then put the fitting on.Now put the cover with hose and fitting on the bottle to see if it fits.Now try putting the fitting to your gun.If it is hard to get the fitting on due to the proximity of the guns tank you can pare a little plastic off the cover .Now you have a cheap way to keep your charging sett-up clean from animal hair ,lint, and dirt.I have an extra adapter for another gun and it fits in the bottle so I always know where it is.I hope this will be helpful.-Tin Can Man-

          • TCM
            I just get a extra male foster fitting and a double ended female 1/8 pipe threaded coupling and a 1/8 pipe plug and plug one end of the coupler with the pipe plug and thread the male foster in the other end of the coupling and now you have a dead head plug to put in you fill end of the pump fitting and if you put pipe dope or telfon pipe tape on the plug and male foster and tighten securely it will also double as a test plug to check for leaks in your hand pump by allowing you to easily pump it up to 2000 psi with just two or three pumps and use soapy water to make sure there are no leaks in the pump or hose itself.


          • TCM
            I use a 1/8 pipe plug, a 1/8 pipe coupler and a male foster fitting and use Teflon tape or pipe dope to seal the pipe plug and male foster in the coupler and it now will serve two purposes. One as a plug to keep dirt and other foreign matter out of the fill fitting and also as a test plug to check for leaks in the pump and hose itself very easily with just a couple pumps you can have 2000 psi in the pump and hose to spray with soapy water to find a leak.


  4. B.B.,
    Thanks for the continued work on the Diana 45. Mine likes Crosman Premier Lites in the box also as well as H&N Field Target Trophy 8.64 grain pellets. It does not like Barracuda Match pellets very well. They are a little heavy for this power plant, I think. Looking forward to more.

  5. BB,

    I have an almost related question. Are the Diana air rifles that PA is selling strictly Diana or are they also marked RWS? I know they have upgraded stocks and sights for the most part. I have been waiting almost impatiently for their N-Tech line to be available.

  6. This is going to be a funone to follow.
    While visiting an old friend I noticed he had an air rifle. He said he shot at a mouse and missed. I asked if I could sight it in for him. After a week of tuning the mice better look out. Just a clean ,polish and lube makes a huge difference. New scope I gave him helped also.

  7. Well this is off topic but I’ll ask anyway 🙂 It appears that I am succumbing to yet another expensive pastime 🙂
    I am strongly considering a TX200 but after seeing the post on the custom stock work done on the BSA Airsporter I’d very much like to purchase something similar for the TX200. A search on google does not seem to reveal much, can someone here point me to some custom or aftermarket stocktakers for the TX200? Any recommendations on scopes and mounts would also be much appreciated. I offline discussion is more appropriate my email is ragnar51atoptonline.net

    Thanks guys!!1 Kevin in CT

    • Kevin in CT,

      Welcome to the blog. We don’t worry about staying on topic here, so ask your questions.

      There are a handful of good airgun stockmakers that come and go with time. Prepare to spend a lot of money, because the wood blanks like that BSA cost more than a TX200. But if you want them, they can be had.

      I’ll let our readers suggest who you should go to.


      • Kevin,

        this fellow has been at the CT airgun show and the Roanoke shows and showed some lovely stocks on a selection of rifles – including the TX200 Mk III I bought from him in 2013.

        janfkraner at aol dot com

        He lives in NJ and claims to have been doing stocks, checkering, stippling and “competition grade trigger work” since 1990.

        Good luck!

        Fred DPRToNJ

    • Kevin in CT,

      Be very careful when dealing with custom airgun stock makers. As B.B. said they come and go on a regular basis. When they disappear many custom stock makers have taken airgunners money and their guns. These were guys that had been around for years and built trust in the airgunning community. Not just one custom airgun stock maker but I can think of 5 off the top of my head.

      Would suggest you keep an eye on classifieds or auction sites and buy a stock that already exists. Funny thing though, I can’t remember seeing a custom sporter stock for a TX200. Suspect the reason is because there are so many factory options available new and used. Right hand, left hand, checkered, fish scale, beech, walnut, etc. Suspect the other reason is because the factory stock for the TX200 has such classic lines and is so nicely finished.

      I’ve seen lots of custom FT stocks for the TX200 though. Here are a couple from stock makers no longer making stocks:




    • Kevin,

      Go ahead and buy yourself a TX200 MKIII with a walnut stock. Once you have one of those beauties in your hand, you may not “need” to have someone carve up that beautiful stock. Go to the PA site and look closely at the pictures and look at the checkering on them. Anyone who has held one of these things will tell you that the pictures do not do it justice. They are makeyourkneesweakIhavelostbladdercontroldropdeadgorgeous!

      • Hi guys, thanks to all for your helpful replies!! To tell the truth, the factory walnut stock is looking better & better to me, some of those custom ones are just too dang big!!. I did a quick Google on the CT airgun show and it looks like it’s no more, it that correct?

  8. A great addition to this blog would be an index of all articles that BB has made. There is so much information contained in these blogs, that it would really be nice to find specific articles easier than the search function provides.

    • L.Roach,

      I agree, but have no clue how that would happen. You have to go through a lot of stuff just to find a specific thing you are searching for.

      In doing so however, you discover new things too, so it’s not all bad. B.B. does a great job. In reality, it seems that it would take a lifetime to absorb it all. I tell my self,…” its a hobby,…take your time and enjoy the journey”. Now if I would only listen to myself! 🙂

  9. Tom, as to black smithing the front sight, when you hit the vise with the 2 lb. Hammer which we all have, do you hit the side of the vise or the flat rear anvil area ? I have never heard of this method and it has to be one of the top gunsmithing D.I.Y.
    Thank you and Edith very much, it is my first Mug of Trader Joe’s Bay Blend Ultra Dark Roast..
    “Old Town” Orcutt, California
    Named after the very first Petroleum Geologist.

      • BB
        Were the threads in the front sight stripped out so that it would not tighten down to be tight or was it just sprung out to much for the screw to properly tighten it up.

        If the screw threads are stripped you could have used a nut on the end of the screw also to secure it in place, it may not have been as visual appealing but would insure that over time shooting that the metal does not relax again and become loose like you found it to be.


        • Could just retap the threads, that’s how Id go if it was stripped, but speaking of screws, do those groups look like the two point spray of a loose screw(s)? That’s exactly what the a.mag was doing when the screws were coming out before loctiteing… just sayin’…

          • RDNA
            I would have to see it up close and personnel to see if there was enough meat to go up one screw size instead of a nut.

            But it could be that the screws have worked loose since the sight was loose and sprung as the rest of the gun has been subjected to the same forces and time.


    • Pete Hallock
      The hitting of the vise is so that the molecules that were just put udder stress by squeezing the part down to a tighter clamp dimension are put under stress and hitting with a hammer relieves that stress and cause them to move and relax so that the movement of the metal will take a set in the new position.

      It is an old mechanics trick when adjusting the gap on a spark plug that when you get the gap set to what it should be you lightly tap the side of the plug on the wrench flats with a hammer to set the gap so that the metal of the ground electrode does not return to its former gap once installed and heated to operating temps in the engine. If this is not done the plug will return to the gap that it was at before being adjusted and all the work of setting the will be for nothing.


  10. Tom,

    You write that the front sight dovetails are ‘swagged’ into the barrel. What does that mean?

    When I hear ‘swag’ I think ‘Scientific Wild Ass Guess.’ You don’t mean that, do you? But that is a bonafide term in the military and world of engineering.



  11. B.B.

    On buzz elimination – try to use a “shim” made of coke bottle inside the piston. A simple rectangle – piston long, 3.14 piston inner diameter wide and with “petals” like that ^^^^^^^^ on the upper side to be turned at the right angle and pressed by installed mainspring. Every Diana that goes through my hands gets this and it kills a lot of felt buzz and mechanical noise, contributing to comfort and more importantly – accuracy. Just watch that the edge was 3-4 mm out of the piston, because I noticed that the buzz itself starts on the edge of the piston and the spring.


    • Duskwight,

      Ahh! The dreaded coke-can or bottle shim! 😉

      I am hoping to button this piston with the help of the owner. That way I accomplish several things and can show a buttoning job to the readers. I also want to make a new spring guide and to tighten the spring-to-piston-rod clearance.

      Lacking that, I probably will resort to the old-time cures. I may show them anyway — so people understand what we are talking about.

      How the heck are you able to follow all this in a foreign language? That’s what really freaks me out!


      • B.B.

        Not all the time, but I try to read every article in your blog. And I believe English is easier to understand for Russian speaker then vise versa. After all, English is my second working language besides weaker French, so in fact it’s not a problem at all. Or, as somebody suggested one time, I’m a fat troll sitting somewhere in Midwest and pretending to be Russian 🙂
        Buttoning works nice, also adding some speed as it eliminates piston sway. Will you just stick “dots” or cut and insert rings?
        With tighter guide rod and buttoning that’s almost half of a “max piston job”, adding I’d say 60% of possible improvement. In my experience “max piston job” also includes that dreaded shim (bottle, I insist, as it is slickier 🙂 ), new better seal and re-greasing the spring. Custom spring is a whole another story, of course.
        Waiting to see your story.


        • Duskwright
          Do you mean coke can instead of bottle as glass would be hard to make a pyramid shape with and most likely would be in a bunch of little pieces the first time the spring was compressed.


          • buldawg76

            Comrade, I have heard from a reliable source, that those Americans use plastic for coke bottles. Just imagine that!
            Any 0.5 liter plastic coke bottle with flat (un-ribbed) walls can be turned into at least 2 shims for the piston, count what can be done with 2-liter one. That is capitalist decadence and opulence at their top, as we are forced to smuggle thin PET plastic from our spaceship factories under the pain of being sent to Siberian camps for re-education!


            • Duskwight
              Ok I admit it I am still stuck in the 70s and you got me good there comrade as I do not consider the 2 or 3 liter plastic containers that soda comes in as bottles, but then I don’t drink soda either unless it has some other spirits in it. So my mistake as yes I can see how a plastic coke bottle would make a very good shim or sleeve to allow for smooth and slippery movement of the spring coils over it.

              I associated bottle with glass not plastic so I guess I need to get my head out of the sand and join the 21st century LOL. Not a chance of that happening any time soon.


  12. Tom- I’m new to this blog and can’t find an e-mail address to ask you a question. Please bear with me and my tech naivete. What do you think about the FX Indy as a survival rifle? and as a hunting rifle?


    • Welcome to the blog!

      I like the look of the Indy. I like that it has a 24-inch barrel And no one can argue that FX is not a great airgun. No reason it wouldn’t do everything you need.

      If it appeals to you, I say — go for it!


  13. “How the heck are you able to follow all this in a foreign language? That’s what really freaks me out!”

    English *is* the world language and not being able to use English language resources on the Internet would feel to me like a disability 🙂

  14. BB,
    You said “A short-stroke piston needs a heavier mainspring to generate the same power as a longer-stroke gun…”
    Didn’t you mentioned in one of your article that a stronger spring doesn’t generate much power, but a long piston stroke does?

    • Joe,

      I am so proud of you for remembering that! That explains why some airguns, like the HW35, can never be boosted more than a little. Same for this 45, I am afraid, and for just that reason.

      But maybe you are asking whether a stronger spring will give ANY boost to the 45? I don’t know. What I do know is that without increasing the stroke, you’ll never boost the power that much.


  15. To be fair, German *is* a pretty difficult language. It has three articles where English only has “the”. It has a distinction between “Du” and Sie” where English only has “you” nowadays.

    It also has the interesting ability to chain any number of words together. “Druckluftwaffe” (air pressure weapon). “Druckluftwaffenschießverein” (club for shooting air pressure weapons). “Druckluftwaffenschießvereinsunfallversicherung” (insurance for accidents in clubs for shooting air pressure weapons). Cool, isn’t it? 🙂
    I made those up, but they *are* correct words…

    German is of course related to English and very different from Chinese or Russian. So yeah, those guys have it harder 🙂

    I also had English lessons in school and I picked up a lot of additional stuff from video games, movies and the Internet 🙂

  16. I can give some insight into putting stronger springs into the HW35, a shorter stroke than the Diana in question.
    My rifle was leather sealed with the original spring and produced 9.2ft/lb in 22 cal, given the state before restoration of the outer I purchased a ptfe seal conversion for both the piston and breech and a swedish Titan XS no 4 round wound spring, this made the sum total of 0.2 ft/lb difference and was intolerable to shoot, like car suspension breaking next to my face….utterly inaccurate.
    A little scratching found that the OE parts required a new piston, and that I had inadvertantly shortened the stroke by a fifth of an inch with the conversion.
    I duly replaced the piston and seal with original parts and reduced the spring by two coils, it still kicked like a mule…and produced 10 ft/lb
    Somewhat frustrated by this I replaced the original spring….and it shot sweetly again, now at 10.2 ft/lb
    I left it like this for a while (2 years or so) and then replaced the spring with a standard weihrauch item, a rotation washer each end and a seal with less of a parachute to it, 10.6 ft/lb…and there it stayed for six years until I changed the guide for a Delrin item and sleeved the piston….at the same time I deep cleaned the compression tube and ran a little thinned adhesive into the back of the breech block (weihrauchs have a bevel that should be weld filled on the inner face but it rarely is and in fact on late 70’s and early 80’s models often have fissures).
    It then produced 10.7 ft/lb and still does…with a 7fps variation over 30 shots.
    If I had a later model the transfer port is slightly reduced to suit the parachute seal and they can be tuned to just over 11 ft/lb without any loss of shootability.
    Oh you can put a beefy spring in and maybe get 11.7….but it will be awful, in my opinion heavier springs are an utter waste of time in a short stroke gun.
    With the Diana 45 I would anticipate around 11.5 ft/lb with original parts and sympathetic lube, with some carefull sleeving and a well fitted PTFE guide (absolutely NOT tight), a more efficient piston seal etc maybe a smooth12.5.
    With a silly spring it’ll do 13 ft/lb but break your cheekbone.

    • Dom,

      Was this Russian, French or Chinese that you were writing in? LOL. Actually, I know very little about the engineering aspects of springers although through this blog I am learning whether I want to or not. I can shoot them very well though.


      • Sorry G&G, when I write a post on my phone under distraction, it often comes out a bit gabbled.
        In short, it tends to be the amount of air that is being compressed behind the pellet rather than the speed it’s being compressed at that dictates the velocity, in the past with leather seals and larger transfer ports you tended to get marginally higher results with a stiffer spring sokely because it had less time to leak past……but they ALWAYS have a cost in recoil.
        I think these days that I have done a successful tune if I have smoothed the gun and maintained the power having REDUCED the spring a coil or two 🙂

  17. BB

    You have occasionally bragged on the faithfulness of your Hill pump and I bought one based on your, and others’, recommendations and am quite happy with it. A blog on it covering preventative maintenance (even tho I believe you’ve indicated yours has not needed any maintenance) and any repairs or parts replacement that can be made at home and the specific fittings needed for at least the two most popular filling probe/connector methods would be most welcome. You know…just dash off something in your spare time…no pressure. 😉


    • John,

      Here are all my maintenance tips for any hand pump. KEEP IT CLEAN. And keepa you hands off it!

      I used to repair hand pumps at AirForce and regardless of what you may read, they are not simple mechanisms. They are complex, and require clean conditions.

      Two things ruin hand pumps — dirt and owners who think they can take them apart.


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.