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Education / Training Pro-Guide spring retainer system for RWS Diana rifles: Part 3

Pro-Guide spring retainer system for RWS Diana rifles: Part 3

by B.B. Pelletier

Part 1
Part 2

Now it’s time to assemble and test the RWS Diana 48 with the Air Venturi Pro-Guide spring retainer installed. Because I removed the piston to photograph, I put it back in the gun first, but you normally wouldn’t take it out. So, the Pro-Guide system goes into the spring tube white end first. That’s the end with the guide inside the spring.

I mentioned in the last report that the Pro-Guide isn’t as long as the factory spring, so the trigger assembly also sits lower in the spring tube. Now the rifle is put back into the mainspring compressor again, and tension is put against the end cap shelf. As the tension increases and the end cap moves into the spring tube, it may twist so the pin holes in the cap go out of alignment with those through the trigger block and the mainspring tube. The trigger block will limit the twisting, but the black plastic end cap can get out of alignment just enough to make pin insertion impossible.

When the compressor bottoms out the end cap, the two pin holes are close to up-and-down alignment with the holes in the spring tube, but you may have to back off on the compressor tension just a touch. Then, you may have to work the end cap to one side or the other so the pins can be tapped through. A tapered punch is a good tool for this job, and you may have to start out using a thinner pin punch until the holes are close enough to insert the tapered punch.


The trigger unit is installed in the mainspring tube after the Pro-Guide system. It slips down into the mainspring tube farther than the factory spring because it’s shorter.
Tap in the rear pin first. Don’t force it, but to get it started may require a few hard taps with a plastic hammer. Once it starts going into the hole, it’ll pull the trigger block into perfect alignment with the mainspring tube..and the rest is easy.

When the rear pin is all the way in, pull the trigger once to release it. If you don’t, you’ll discover later that the rifle won’t cock and the safety slide will be stuck. After the trigger’s pulled, tap the front pin into place. The rifle may then be removed from the mainspring compressor. The next step is to connect the sidelever. Insert the hinge pin first, making sure the two large washers are on either side of the hinge bushing and inside the flange that’s welded to the mainspring tube. The smaller washer goes under the head of the hinge pin.

After the hinge pin is installed, you can connect the cocking link with its pin. Be careful that the link hasn’t been unscrewed while you worked on the rifle; because, if it’s too long, the sidelever won’t stay tight against the side of the rifle after the gun’s cocked. If you have that problem (you will sooner or later), just tighten the link by screwing it in as far as it’ll go. That usually fixes it. It’ll have a little bit of flex as the sidelever is brought close to the spring tube, then it snaps the sidelever closed and tight against the tube when adjusted correctly.

Next, put the action back into the stock and tighten both screws. You’re ready to test the Pro-Guide system! This procedure takes someone familiar with RWS Diana rifles about 15 minutes, start to finish. If you’re doing it for the  first time, allow about an hour.

The velocity of this rifle shooting .22 caliber Crosman Premiers with the factory mainspring was 797 f.p.s. With the Pro-Guide, it measures 805 f.p.s. That’s not a large increase, but I think the rifle will continue to get a little faster as it breaks in with either the factory spring or the Pro-Guide installed. There’s still a little velocity fluctuation because of how new the rifle is, and that was observed with both the factory mainspring and the Pro-Guide. Remember, there was no lubrication or anything else done during this installation.

Shooting notes
With the factory spring, I could feel a small amount of buzz after every shot. It wasn’t objectionable and died off quickly. With the Pro-Guide, there’s no buzz whatsoever. Just the solid “thunk” of the piston coming to rest. I can feel a definite difference. There’s no measurable difference in cocking effort between the Pro-Guide and the factory spring, and the recoil also feels the same.

Is the Pro-Guide for you?
The advantages are zero vibration, possibly a small velocity increase, and a drop-in tune that you can do at home, as well as customize in several ways. You could add more lube to the mainspring if you like or you could put a washer ahead of the forward part of the Pro-Guide to bump up the velocity a bit. The Air Venturi Pro-Guide spring retainer system gives you one more alternative to expensive tuneups, and it’s one you can install yourself if you’re so inclined. Of course, you can also order the Pro-Guide to be installed when you buy the gun.

What’s next?
Well, I won’t insult your intelligence by claiming the Pro-Guide increases accuracy! Instead, I thought it’d be nice to see what the Pro-Guide can do for a .177 RWS Diana 34 Panther I’ve had for over a year. This is the same rifle I tested for you, and it’s also one of the rifles I used for the Leapers scope base development project. It now has many hundreds of shots through it. You’ll get to see what a Pro-Guide can do for a rifle that’s already broken in.

This just in!
A customer just submitted a nice review of the Pro-Guide, and I thought you’d like to see what he has to say. It’s also posted on the Pro-Guide product page:

“I did the install on my 34 Panther and it was quick and easy. She was clocking in at about 776fps prior to this addition and is now clocking in at around 839fps (10 rounds each, 14.3 grain chps). The gun cocks much smoother now and there’s a solid ‘thunk’ when fired. The recoil feels a little harder than stock, but it’s a nice and solid feel. I have another 34 that has a well-known aftermarket tune kit installed. That rifle shoots really well, though there was actually a small drop in velocity after installing the other tune kit, but her accuracy is incredible. I’d take accuracy over velocity any day, but won’t complain if I have both. There’s lots of speculation and rah-rah going on about this pro-guide kit so I thought I’d be one of the first to give it a try. So far so good; easy installation, good fitting parts and a velocity higher than that advertised for the stock gun. I’ll post a follow-up after a couple hundred more rounds with this to see how it holds up compared to my other 34 with the other custom tune/spring kit installed as far as durability, velocity and accuracy goes…”

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.

51 thoughts on “Pro-Guide spring retainer system for RWS Diana rifles: Part 3”

  1. B.B.

    How thick should the “washer” be if I’m looking to get a little more velocity out of the Pro-guide?

    And if I understand it correctly, the washer goes in FOLLOWED BY the Pro-guide correct (washer would be between the back of the piston and the delrin Pro-guide front retainer)

    Good write up though looking forward to a little more chrony numbers with the 48 and the new guide.


  2. A bit misleading review, perhaps by the customer… I dont think I’ve seen a 20+fpe RWS 34 Panther. These are 12-13fpe guns.

    776fps with 14.3gr BEFORE the tune and 839fps AFTER…. someone has a bad chrony or is just full of garbage.

  3. Scott,

    The washer goes in first, then the Pro Guide. You have almost 0.10″ to work with, but a single washer could make a 30 f.p.s. difference.

    I wasn’t going to do anything more with the 48, but now that you mention it, I’ll put a washer in and we’ll see what happens.


  4. Shadow express dude,

    The Pro Guide has to match the internal dimensions available in the gu, so the answer to your question is THIS Pro Guide will not work in other rifles.

    Could a Pro Gude be developed for other models? Sure.


  5. BB, I am intrigued by this new guide type…so my scientific curiousity leads me to ask… how is velocity increased using this system? I am familiar with the components of what affects velocity in a springer powerplant…is it just a stronger spring?

  6. davee1,

    Not really a stronger spring. Just more efficiency from a spring of similar power. Instead of wobbling around and vibrating, this system keeps the spring in check, only letting it do work. Hence a small velocity increase.

    At le4ast that’s what I think.


  7. B.B.,
    Thanks for the sentence, “pull the trigger once to release….”.
    I’ve run into that situation with my 54 where it was locked up after reassembly, so I’d take it apart again, and fiddle a bit, and put it back together, and then it was sometimes fine, sometimes not. Now I know what was happening!
    Thanks again for one of those little, “AH HA!” nuggets that makes a big difference to those of us that are still learning. And I hope that includes 100% of us.

  8. B.B.

    Looking forward to the washer chrono results. If that can get the 48 to do some mid-high 800 fps numbers with 14.3’s, then that’s what I’m doing in mine. Thank you for doing this.


  9. B.B.

    Do you know if the big PA inventory clearance in late September will have an online component? Sounds pretty fun, and I wish I could attend in person.


  10. B.B.,

    Off topic, but do you know of any dealers in the U.S. who still carry Weihrauch pistols, in particular, the .22 versions of the HW45 (Beeman P1) or HW40 (Beeman P3)? Can you recommend any other .22 pistols aside from the HB22 and the recent Beeman P11 (which I’d like if it took regular 1911 stocks).

    Thanks very much in advance.

  11. Weihrauch pistolero,

    Don’t overlook the .22 cal Crosman 2300 and 2240 co2 guns. They’re cheap and capable of exceptional accuracy. I think one of these belongs in every airgunner’s arsenal.

    I’m with you on more airguns being designed for .45 auto grips. That is really a great design feature of the P1.


  12. B.B.,
    In response to somebody’s query regarding the velocity of the JW80 in [hard to find] .25 form, you write that your JW75 produces velocities of 571 with Kodiaks and 813 with Diana Magnums. I am guessing that you mean .25 caliber, as that is what the writer asked? If so, that means that your rifle is sending the 31 grain Kodiak .25 at 22 foot pounds. What is the Diana Magnum? If it is going at 813 fps, then it must weigh about 15 grains to produce a similar 22 foot pounds. Is it .22 or .25?

    It is my understanding that the JW80 produces between 27-28 foot pounds in .22 caliber, which I guess you could say is “close” to B.B.’s 22 foot pounds in his JW75. I like to think that one gets something more for the extra pulling one performs with the 80, that the extra pull is somehow worth an extra 5-6 foot pounds… probably not.
    B.B., Why would somebody want an 80 versus a 75?
    – Dr. G.

  13. Dr. G.,

    You read right, but you didn’t explore the entire report, which is here:


    While the .25 Kodiak was indeed 22 foot-pounds, the 20-grain Diana Magnum was over 29 foot-pounds. That is what is so important about doing the testing of these guns. That report shows a linear progression of power as the caliber increases – except for .20 caliber, which regresses.

    A JW 80 will usually produce 1-2 more foot-pounds of energy, but I have tested one side-by-side with my 75 and they came out the same.



  14. B.B.

    I’m curious if you know of anyone that has done any testing involving spring gun efficiency?
    Looking mainly at cocking effort first, the weight if the rifle second and finally the energy it produces. Does a formula already exist?

    What do you feel the most efficient spring rifles arewere?


  15. Thanks all, I’ll try DAK and check out the 451 as well.

    And thanks Derrick. I like what I’ve seen of the two Crosmans you suggested. Was hoping to avoid CO2 though. I’d be happy if the RWS P5 or Beeman P1 would just come in .22 these days.

  16. Jeff,

    Very interesting stuff from Vince. Little more involved than I was thinking.

    Here is my simplistic opinion on the matter.
    The energy I need to shoot a spring rifle involves holding and cocking it. (I’ll leave trigger pull out)My return is the ft lbs it generates.

    I have three made up scenarios, to explain my thoughts.

    BSA Lightning XL .25 cal

    Hold 6.5 lbs and use 29 lbs of effort to cock for a total 35.5 lbs of “work”.
    I get 16.5 ft lbs at the muzzle.
    That means I have a 46% return on my effort.

    HW50S .22 cal

    Hold 7.0 lbs and 30 lbs of cocking effort (37 total) gives 12 ft lbs. The return on the work is 32%

    Beeman R-7 .177 cal

    Hold 6.1 lbs and 18 lbs to cock (24.1) for 7 ft lbs. The return is 29%

    So it would seem the BSA makes the best use of my effort, or is the most “efficient” as far generating power of the 3, too bad it has the worst trigger and accuracy.
    (My Webley Patriot also had a similar high percentage)

    My disclaimer is not only am I not an engineer, I am not that bright. But I made up this unsophisticated method sometime ago to rate spring guns, and wondered if someone had a more precise method. (That doesn’t require tearing a gun apart, etc)

    What I would like to find is a 7 lb rifle that takes 23 lbs to cock and puts out 30 ft lbs. : )


  17. .22 pistolero,

    Don’t fear the CO2–it’s no big deal.
    Take a look at the foot pounds you can get from some of the Crosman single shots, too. If you’re really a nut like me, check out an old Crosman bulk fill Model 112 .22 cal.


  18. Volvo, I’m not sure exactly what you think you’re calculating when you add the rifle weight and the maximum cocking effort. In any event, your result is something that is in ‘pounds’ (as you correctly state), but ‘pounds’ is not ‘work’ or ‘energy’. Energy is pounds x distance, otherwise a 3 pound book sitting on a table would constantly be producing energy because, well, it weighs 3 lbs. In reality it doesn’t simply because it is not exerting that force over a distance.

    Another thing to remember is that you can’t assume that the overall, average cocking effort is the same as ‘peak cocking effort’, which is the number usually cited. Theoretically it would be possible to calculate teh energy put in to a rifle from cocking effort vs. cocking stroke, but the mathematics for THAT get real funky – even before you try to remove frictional losses.

    What you’re trying to do, in effect, is akin to calculating the gas mileage of your car by taking into account the vehicle’s weight and the size of the gas tank.

  19. B.B.,
    I was so very pleased with the performance of the 850 that I bought a couple years ago that I bought a second one, 1.) hoping that it might be more accurate than the first, and 2.) anticipating that my first one would give up the ghost at some point, and I did not want to be without this air rifle for very long.

    I had tested the original 850 with about 18 different brands of pellets until I found that the best pellet for indoor 10 meter shooting was the RWS hollow point, about 14.4 grains. It reliably produces unweighted 8-shot groups of 4/16″ and when using weighted pellets produced 3/16″ groups. The other 17 types of pellets, including all the popular types that are mentioned on this blog, produced unweighted 8-shot groups of 5/16-9/16, and this is with shooting at least 3 sets of 8 shots (and often more) for each type of pellet.

    I was very curious whether the 2nd 850 (also in .22) would similarly shoot best with the RWS H.P. or would it do better with a different pellet. I was also curious regarding the accuracy of the two air rifles compared to each other using whatever pellet turned out to be best.

    The first interesting thing that I learned was that it took at least 300 (but not many more than that) shots to get the accuracy stabilized and maximized. Then, I shot all 18 types of pellets, at least 3 sets of 8-shot groups each. I made all my measurements to be rounded off to the nearest 1/16th of an inch, and the findings turned out to be reliable.
    B.B., 1.) How close in accuracy do you think the two rifles were using the best pellets for each, and 2.) Where do you think that the RWS H.P. pellets placed amongst the 18 tested pellets with the 2nd 850?
    P.S. There is no point in having the word verification hardware for this blog. There are no financial stakes involved, and it is simply annoying. – Dr. G.

  20. Dr. G.,

    From your viewpoint, word verification is pointless.

    From my viewpoint, it elimiates 10-20 spams and hijacks a day. Since I now answer 30-50 legitimate questions every 24 hours, the eliminatinoon of 1-2 additional hours of work is not insignificant.

    Verification will remain.

    As for the other question – how should I know? I will guess that the second rifle did not turn out exactly like the first. As for the best pellet, there is a greater likelihood that it is the same one.


  21. B.B.,
    You are correct on both counts! How did you know?

    The same pellet turned out to be best on both rifles, and yet the second rifle did not turn out exactly like the first in that the order of pellets (from 2nd best to #18 did not match up the same).

    If you want the results of the top 5 and worst 3 for each gun then let me know. – Dr. G.

  22. Dr. G.,

    Well, mine was just a guess, but here’s the rationale. The rifling equipment doesn’t change often at a manufacturer’s plant, so the bore size, muzzle choke and breech choke, if any, will stay the same. The twist rate and mean bore size will also stay the same. Those things favor the same pellet being the most accurate, gun to gun.

    But each barrel is still an individual, which is why I guessed the second rifle didn’t match the first. It was a lucky guess.

    Yes, please publish those results. Many of our readers will enjoy seeing what you discovered.


  23. Volvo,

    I agree with Vince that your formula is a technical mess:) if used to calculate efficiency, but it does appear to be a reasonable attempt to characterize usability or enjoyability… perhaps the “shutzvergnugen” index?

  24. Me,

    I have no plans to review those rifles. They are nothing but cosmetic cousins of the 34 Panther I have already reviewed. Also, I’m going to install the Pro Guide in the 34 Panther, which will give it another review.


  25. Bg – farmer

    Not everyone appreciated the Taylor Knock down formula at first either. I may have to wait until after my death for my genius to be valued. Perhaps if I include Pi?

    I should get a slight break, since I’m still using a slide rule for my calculations.

    When I have more time, I will make another feeble attempted to accredit my thought process. At the very least, entertain the more technically savvy readers, and affirm the money they spent on education was worth it.


  26. B.B.

    I will try and locate a copy of the “The Airgun From Trigger to Target” Thanks.
    Don’t feel obligated to reply to this.

    Bg farmer,

    I liked what you said about a way to factor enjoyability. I would be glad to credit you with that insight when it comes time to name the calculation.

    Using an automobile analogy, a 5-liter engine in a 1976 Camaro was good for 145hp. A 4.6 liter engine in a new Mustang makes 300 hp. So I think it is safe to say that the new lighter engine is more efficient. I want the air rifle equivalent of the Mustang engine.

    (BB -I know you’re not a fan of the horsepower wars from your R-1 book. Just makes for an easy example)

    In my quest to try and determine what the most enjoyable efficient springer design is currently, I added the Lightning XL to my collection. (I am running out of excuses to justify new purchases.) The HW35 is to the R-1 as the……………?

    I am guessing it would be more appropriate to assign points, 1 thru 10 based on each component of the rifle. But I dislike the subjectiveness of these systems and the “gotta have it factor” annoys me the most in auto rankings.

    My new Diana 25 that is 74 years old makes 5.8ft lbs with about a 15 lb cocking effort in a 5.2 lb rifle. Anyone want to figure the Volvofarmer Enjoyment Factor for it? (I know some of you calculated this for your rifles yesterday for the same reason we all do this, the fun of it)

    Let me know if you have a rifle that goes over 55%


  27. Vince

    Thank you for the expert feedback. I was not implying any of your data was faulty, just way more effort then I would be willing to expend.

    I had to smile at your last comment, as the worst gas mileage I ever had from any truck was a heavy Ford with dual gas tanks. One was 18 gallon and the other 16, if I recall correctly.

    So yes, I learned to look at the weight of a truck and size of the gas tank capacity to guest-a-mate gas mileage.


  28. Volvo,

    See I told you we are a lot a like… for some reason I get you loud and clear….
    In 1968 my dad had a new 142 volvo with the su carbs… I think it was 95cu in and 115 hp… and my 1966 fastback mustange only got 150 odd hp from it's 289 cu inches…

    Tighter machining, better fuel feeding, I don't know, I'm a wood worker…

    But I know the 142 could beat my mustange if any curves were involved and stay close in a straight away. whether it was me or my dad driving it…so it wasn't the driver.. (yes he was a bad influence on me sometimes… he was always a kid at heart.)

    And get 30 mpg when I wasn't racing it.. and 25 when I was.. while the mustang got 12mpg and was worn out after 125,000 miles and the volvo 142 went 500,000 on that engine and trans…

    The 142 of springers might be the one you have already, the BSA Lightning XL .25 cal… I doubt it will be beat..

    Aren't there some compound cocking guns with 1,200 fps in .177 or 1,000 in .22 with 27lb cocking effort, but it weighs 10 lbs.,, breaks scopes, and kicks like a mule.. is that the patriot?

    I think the weight of the gun is the factor that your loosing people on… but that is important to me..

    and the 142 or PCPs is the S410…

    Any way, at least there is one who speaks your language…..


  29. Wayne,

    I HAVE to comment! I heard all those bulletproof Volvo claims, so when I was living in Germany in the late 1970s, I let my 144 (or was it a 142?) out on the autobahn for just 20 minutes. It got up to 95 mph, indicated, and then threw a rod! I never drove it again.

    My BMW 2000 TI Lux, in contrast, got up to 128 mph, indicated, and ran out of autobahn at the Nuremberg autobahnkreutz, coming south from Grafenwoehr. I foolishly traded it for another car when it was still running perfectly.

    My one experience with a Volvo demonstrated that they are not all the supercars their owners would like them to be.


  30. B.B.

    Sorry about that.. you must not have told her “you loved her” often enough…or at all!!! I bet you talk to your guns…

    I’ve had about 25 other 140, 240, 740 and now 960s wagons, through the years…running them as little pick-up/mini vans, hauling lumber to small orders.. or bringing the bird feeders and bat houses I made to the stores I sold to…

    I got average 400,000 per engine and trans…not one blew up on the way..

    I haven’t gone fast again, like I did when I was a kid, but my dad and I drove that 142 he bought from southern cal to Joplin Mo. in 28 hours.. we held it between 90 and 100 for 3 hours racing a caddi through the desert..


  31. Cowboy dad here.
    In ’76 I got a great deal on a ’74 142 GL…a demo buy-back…got it for $3600 which was a 50% less that what would have been fair.
    At the time I was seeing a woman in Seattle (I live in Edmonton) a distance of about 1600kms (1000mi).
    Twice a month I’d leave on Friday after work, about 6PM and drive straight through, usually hitting Seattle about 9AM Saturday, averaging about 135kph (85mph) the entire distance.
    The thing never missed a beat in about 20 such trips.
    Best car I ever had. I sold it for $1000 with 700,000km (440,000mi) on the clock. Burned a bit of oil but the person who bought it drove it another year till they totalled it.

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