Crosman 38T Target revolver: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

38T
Crosman 38T.

Part 1
Part 2
Part 3
Grips & tips

History of airguns

This report covers:

  • Crosman ashcans
  • How did they do?
  • The test
  • RWS Superdome
  • Crosman ashcan pellets
  • RWS Superpoint
  • Discussion and summary

Today will be the last report on this .177-caliber Crosman 38T target revolver. Reader Billj commented to Part 2 that ashcan pellets were the most accurate in his 38T, but after some discussion he mentioned that they weren’t Crosman ashcan pellets. They were Ampell pellets.

Crosman ashcans

Ampells I can’t remark on, but Crosman ashcans I have. For the record, they aren’t called ashcans. Crosman called them Superpells. We call them ashcans because they look more like that than they do a conventional diabolo.

38T Ashcans
Crosman “ashcan” pellets are uniquely shaped. But are they accurate?

The first thing I did was weigh 10 of them for you. Here is what I saw.

Pellet….weight
1……………8.4
2……………8.3
3……………8.3
4……………8.4
5……………8.3
6……………8.3
7……………8.4
8……………8.3
9……………8.3
10..…………8.3

That’s pretty consistent. Most modern pellets don’t do any better.

How did they do?

Well, for starters ashcan pellets didn’t load into the rotating cylinder very well. The spring-loaded pellet loading tool wouldn’t push them all the way into the chamber unless I pressed down and pushed on it very firmly. It felt like they were much larger than average diabolos.

38T ashcans loading
Every ashcan pellet went into the rotating cylinder this far and then had to be pushed in the rest of the way by hand. They went in with a click.

Just for fun I measured the heads of a few of the ashcans. They were all larger than 4.56mm, which is as large as my Pelletgage goes. So they are large!

The test

I shot off a sandbag rest at 10 meters today with my hands resting on the bag. I shot 6-shot groups because that’s how many pellets fit into the 38T cylinder.

RWS Superdome

I started the test with RWS Superdome pellets. In Part 3 they grouped the best, with 6 going into 0.97-inches at 10 meters. Today these were the first pellets I tested, with the hope that they would groups similarly. And they did. Today 6 Superdome pellets made a 0.999-inch group between centers at 10 meters.

38T Superdomes
Six RWS Superdomes made a 0.999-inch group at 10 meters. 

That was close enough to the group shot on Day 3 that I feel this 38T really likes this pellet.

Next up were the ashcans.

Crosman ashcan pellets

I already mentioned the ashcan’s sluggish loading. That gave me hope that these Superpells might be wonderful because of how large they are. But alas, they turned in a 6-shot group that measured 1.455-inches between centers at 10 meters. 

38T ashcans
The 38T put six vintage Crosman “ashcan” pellets into this 1.455-inches at 10 meters.

RWS Superpoint

The last pellet I tried today was the RWS Superpoint. The 38T put six of them into 1.587-inches at 10 meters. This is the largest group of today’s test, and it’s also larger that all the groups in Part 3.

Superpoint
Six RWS Superpoints made a 1.455-inch group at 10 meters.

Discussion and summary

Well, that’s it for the .177-caliber Crosman 38T. I always wondered how this air pistol shot and now we all know. The airgun is powerful and accurate. It looks very realistic and functions quite well. For an airgun made no less than 36 years ago, I have to say it gives up nothing to an air pistol made today.

Now, the good news is, we are just half finished with this report. Yesterday’s guest blog by 45Bravo, Grips & Tips, was written about the left grip panel of my .22-caliber 38T that I sent to Ian for a reseal. I told him the left grip panel was wonky and he turned the repair  of that into a guest blog, with a second report on resealing the pistol that’s yet to come.

Then I will test that pistol for you and, because Ian sent me some .22-caliber ashcans, I’ll also test it with them. When this series is over you should have a very good understanding of the Crosman 38T!

79 thoughts on “Crosman 38T Target revolver: Part 4

  1. BB,

    Looking good. Looking forwards to the rest of the reports. Thanks for the weigh and head sort. I remember the “ash can” type pellets from the early ’70’s. As I recall, an 880 is all I had at the time.

    Chris


  2. BB,

    If those ashcans are overly large in .22, I would like to try them in the Webleys. On second thought, no. If they do real well, then I am going to have to scour the world for them and pay “collector” prices. They really did not do that bad. they were spitting out at minute of feral soda can.

    Brace yourself Ian. I used to have a Crosman CO2 pistol. It was the second airgun I had bought. It was absolutely horrible with bbs, but I could hit feral soda cans at 25 yards most of the time with pellets.

    Discussion and summary
    Well, that’s it for the .177-caliber Crosman 38T. I always wondered how this air pistol shot and know (now) we all know.


  3. I have something brand new at RRHFWA, a Wheeler Trigger Pull Scale. I have been really curious about some of these triggers around here and it was not very much at all. I have spent more for a tin of pellets and this should last longer.


    • BB,

      I really like the looks of those ashcans. I can see where they may be lacking in aerodynamics, but I have seen some really klunker airplanes that actually flew that were probably designed by the same engineer.



      • RidgeRunner,

        “…but I have seen some really klunker airplanes that actually flew…” I’ll bet you are referring to mostly radial engine powered fighters! Yea they don’t look near as sleek as Spitfires or P-51 Mustangs but the “Hosenoses” usually outperform their svelte contemporaries. Even this clunker T-28 Trojan: http://www.airbum.com/pireps/PirepT-28C.html
        I have about 1,500 hours logged in the T-28B and C’s 1,000 or so as an Instructor; this is the most fun airplane I have ever flown.

        It is faster than a Speeding Pellet!

        shootski


        • Shootski,

          I just knew I would get a rise out of you. 😉

          I was not referring to the radial engine planes, well mostly. The Wildcat was a dud. So was the Buffalo. The US learned how to build a fighter around those big radials.

          The MIG-23 was a real klunker. Too big and too complicated. The “Century” series were not that great either.

          Many think of the F-4 as a dud, though it really wasn’t. The one line from “Top Gun” that I liked was where the instructor said that the F-4 was the US’s proof to the world that with enough thrust, even a brick would fly. the Israelis took the F-4 and gave it new engines and new wing slats and it would outperform the F-15 in speed, maneuverability and rate of climb.


          • RidgeRunner,

            The IAI project on the Super Phantom was interesting. With the help of Boeing and Pratt & Whitney they got rid of the F-4s Achilles Heel; the J79 smoker. That engine cost us many American pilots in Nam and also saved a lot of Mig Pilots!
            That combination was awful. Whenever I went feet dry I did my best to loose my smoker armed escort!

            shootski

            PS: The Phantom II had a leading edge slat system at the expense of top speed.



              • RidgeRunner,

                F8F was something else i grabbed a few hours for my logbook in a civilian (Confederate Air Force in those days) owned Bearcat trading it for acrobatics instruction. The Bearcat was 100 Kts faster in level flight caused by new thin wing design, the use flush rivet/spotwelding and the R-2800’s two banks of 9 Cylinders created a Hugh POWER RESPONSE compaired to the one bank of 9 in the T-28; it was breathtaking to shove the throttle toward the Firewall! The taildragger Bearcat was a handful on the ground but pure JOY in the air.

                shootski


            • Interesting about the Phantom’s leading edge slat system; learned something new. The Me/Bf-109 series fighters used wing leading edge slats as well – possibly the first aircraft in aviation history to feature them?


              • FawltyManuel,

                Slots and Slats get confused by aviation writers from time to time. Slots came first and are a fixed in place feature.
                “…The Me/Bf-109 series fighters used wing leading edge slats…” The 109 was about two decades late! If it wasn’t the first it was the first leading edge slat system Patented 1919; Handley Page put them on a WWI bomber.
                That name should be familiar to an Aviation buff!
                Lockheed’s Bob Wiele had the first automatic leading edge slats Patent in 1958. The first A/C I flew with active slats was the A-4 Scooter also a fun airplane to fly.

                shootski


          • Israel’s upgraded F-4s were called Kurnass. They were retired in the mid 90s.
            In the late 90s Isreal upgraded Turkish F-4Es to an updated modernized variant of Kurnass. After the upgrade, Nato nicknamed them as Terminators; they’ve turned into air to ground modern marvels. I think F-4 was a great platform; anything could be done with them. They are still in service in a few air forces.
            In 60s, Australians decided to use Mirage III as fighters and F-111 as bombers. The delivery of Mirages were delayed, so they rented F-4s in the meantime. The Royal Australian Air Force generals quickly realized that they had made a big mistake. They wished they had bought F-4s instead of Mirages and F111s. F-4 would have been a better bomber than F-111 and a better fighter than Mirage III.
            The earlier F-4s didn’t have integrated machine guns. The engineers thought that the plane wouldn’t have needed one anymore. After the lessons learned in Vietnam, F-4s were attached a gunpod, which badly effected their performance. In late 60s, the issue was taken care of with the introduction of F-4E, which came with an integrated vulcan gun on it’s nose. In my opinion, despite their few issues, F-Es had been the rulers of the skies until F-15 was introduced.


        • Shootski,

          The T-28 was a popular plane here for COIN (Counter Insurgency) operations. Locally referred to as Tora-toras (because they resemble the Japanese Zero of WW2). Along with the OV-10 Bronco they were the last prop driven combat planes of our Air Force. The FA-50 now is our current jet fighter aircraft.

          Siraniko


          • Siraniko,

            The FA-50 is a really capable and cool looking aircraft. It will be interesting to see how it does over the long haul.
            As far as the PAF OV-10s I always considered the Bronco TOO vulnerable to man-portable SAM. I think the PAF pilots will be much happier in their Embraer A-29B Super Tucano; they are way better looking!

            shootski


            • Siraniko, FA50 is a great versatile aircraft…
              Shootski,
              I’d like to learn your opinions on F-35 as you are truly the expert on the subject.
              I think F-35B (STOVL) is an excellent replacement for the AV-8B; it is better than the Harriers at anything. On the other hand, I believe two new platforms have to be designed from scratch – one to replace the F-15 / 16 / 18, and the other to replace the A-10. They shall share the same computers, engines, and cockpit, and as many common parts as possible, but have totally different platforms. F-35 A, B, and C share only %30 of their parts anyhow. Two new platforms might take that percentage down to %20 worst case scenerio. What do you think about this?

              Thank you!


              • Fish,

                The F-35 when it works is a fine aircraft for overland missions. Remember I’m a retired Naval Aviator who has made actual one engine out landings on the Boat; those can’t be done with the Lightning II. The AV8B was retired before its time due (mostly) to a UK Labor Party induced budget disaster.
                Please no more designed from scratch Joint any aircraft! They have been, almost to the n-1, budget and performance disasters!
                The US Navy needs a two engine F/A-XX which will probably be the last human flown Naval Aviation platform.
                What the US Air Force does about the A-10 will be the usual…unless Space Force beats them to the money.
                Early (reliable) detection of launch capability. Submarine/stand off range Anti-Missile Missiles ( Nuc, KK or HE) are the way of the near term. After the initial exchange the tactical can be decided by whatever is left.

                shootski



              • RidgeRunner,

                Not even close even if it looks like a lot of throw weight ;^)

                The Spad, aka: AD, A1, Skyraider had a max load of 4 Tons. I had a student (Vietnamese) who went to max manifold presure on the ground during Run-Up in one! It compressed the Main Mount Oleos and the prop tore chunks out of the concrete ramp before it departed the airplane…it was his one and ONLY SOLO.

                shootski


  4. Have indeed learned a lot from these reports – think will print them and put them in a binder once the series is complete. The experience with the .22 “ashcans,” loading and shooting them has pretty much matched what you reported with the .177s, B.B. Will see about obtaining RWS Superdomes and see how they do in my 38T.


  5. BB, maybe consider trying the $200. bb revolver Pyramid sells. My hot rodded Gamo revolver is ok, but it is not made like a real gun. I hot rodded my .25 valve too far, now i am looking at guns I dont mod.
    One of my step dads passed after a long life yesterday. Ed Christensen was from San Angelo, Tx.
    He was a die hard Republican, and a gun guy, who had four daughters, all of whom are democrats. The lord works in mysterious ways. He was a fun guy and a great partier too. Thank you for Lizzie, my sister.
    Those ashcans look allot nicer than I remember them..
    Rob



    • Shootski,

      Caught wind of it on my 1 1/4 hr. drive home from seeing my elderly parents on the Rush Limbaugh radio show.

      They are hopeless,… as stuff like this (and I use “this” very broadly),… can’t/doesn’t happen in America.

      At 81 and 83,…. maybe I would not give a flying * either. Sad,… they do. They just see what they are fed in the usual media.

      Chris


  6. B.B. and SELECT Readership,

    I just pulled the trigger on a SIG ASP20 Synthetic .22 caliber with WHISKEY 3 bundle direct from SIG.
    If you are one of the folks that still want one call SIG and place your order on Monday morning early.
    The SIG IT folks are working on the web page because it is not functioning correctly. They do have bundled ASP20 in stock. This may be the last chance to get an ASP…but then again there are rumors that production could resume after the banning of firearms IN THE USA by Executive Order becomes a reality.

    shootski


    • We will see how far the Administration wants to dare go on this notion – and as we already know, the President does not seem to have a leg to stand on…but as long as “they” are willing to accept the consequences at the ballot box down the road, go for it man! Still have faith we are, at least not yet, hopefully never, a nation of Sheeple.

      FM is bad boy. What would the Sisters of St. Joseph say – or worse – do about his warped sense of humor?!


      • FawltyManuel,

        I hope and pray you are correct.
        The big difference I see in our US society compared to during the Clinton’s run on the 2nd Amendment is that these WOKE Cancel Culture types will also likely turn in anyone they think is harboring guns to the authorities. Little do they understand the heritage(s) whose game plan they are playing from!

        shootski


  7. Gamo modster report:
    Made a fore stock platform thingy. Feels good. It’s bolted and glued together, and screwed + bolted on. Easy ish to remove. Shooting off hand it’s very good height for left hand, sitting it will now lift everything up off my left kneee. For prone I have to adjust the but and the slots will be cut longer. Also some kind of wing nuts or knobs will be used. It won’t be super fast to reconfigure. Next stop is testing the two springs at 50m with the scope. Also cheek riser is longtitudianl at the same height ( unlike some combs…) so I can slide along it easily to get the right eye relief depending on stance/butt plate config. Robert.


    • RobertA,

      Did the hamster need to be that long? I don’t think you need a super fast method of reconfiguring. You need a secure and repeatable method of reconfiguring. Probably witness marks with labels as to what position it is used for, also besides the wing nuts or knobs.

      Siraniko


      • Well it’s like this: if I make it short and decide I need it long then….shucks, but if I start out long I can trim it off as I learn how much is too much… it’s not really a hamster… So all up today: a “hamster”, a grip shelf and a steel bar that the butt adjust screws together with. and I extended the butt vert and horiz adust range. AND I took out the weight in the piston. So the 3mm sproing is unpreloaded by 10mm. Seems less jar in the cycle. Might be psychosomatic…. Shoots nice, getting some nice groups in the garage at 6m. ( I am quite wobbly so any group is a good group…) AND it sits on the bench upright! Robert.
        PS the charging lever action is sooooooo smooth. It’s just awesome.

        PPS. I use about 3/4 of that hamster off hand. AND I can use all sorts of weird and wonderful left hand grips!


    • Robert,

      Wow! This thing is getting more and more bizarre looking. Nice job on coming up with a hamster for an under lever.

      Quick to adjust and solid? I do have a clue. For some reason my head goes to a scissor linkage/jack (type) system,… like a car scissor jack. Infinite adjustment. You lock one point and they all lock.

      At any rate,… keep us posted.

      Chris


      • Chris USA,
        This thing is insanely cool. It literally cost about $250 NZD/ $175 USD. and I can hunt cans at 50m … so thats good. ( for the great can cull…) It’s starting to feel more glove like as I get more carried away. Lever action is smoooooooth, the shot cycle is action starting to feel less jarring, the weight is going up so that helps soak up the jarring too. Really comfortable to shoulder. It’s cool. To shift the butt I undo two 6mm socket cap screws, fiddle then nip them up. I glue sand paper on all the friction matted surfaces and they stick like glue. It’s solid! The whole thng comes apart in minutes. I can have the spring out in very short order. and if I put the gas ram in it’s freaking nuts. It’s a great wee thing. I am so chuffed. Now I need a carry box for it…. two nuts and the whole stock assembly is off and one socket cap screw and the grip is off. The hamster has one nut and two wood screw holding it on but I may mod that so it comes off with one nut. Next pics I will do some details of the tricky bits. : – ) Thank you! Robert. PS It used to look like a plastic fantastic! Not any more. I wonder what Gamo would think… Ah those Kiwi’s…. they just have to pull everything to bits!
        Oh here is the trigger. It’s been modded to take the sliding trigger bar. That wooden bit brings the “trigger” fwd at a radial form the trigger pivot. Rather than the pulled back trigger you use with your finger. This changes the progression of the trigger. I have never understood the set back trigger. You are actually moving the trigger up and back.. where as with my set up the trigger slides back pushing against the vertical surface of the trigger. It’s set up single stage with “take up” . You can feel that. Once I get to that point I just pull straight back. No break, no feed back. All mush. But hey It’s as Theoben. There is no way to make it break like glass… Actually you might but that would mean lots of experimental cam profiles… and it might wear out pretty fast. Oh well!


        • RobertA,

          Agree that it is easier to remove wood than adding wood. For a grip I would consider modeling one after the H&K PSG1. It’s good that the 3mm wire responded well to decreasing the preload. Springs just need a minimal preload to minimize their movement after they expand. Without the preload the spring runs a chance of breaking in the long run as it bounces back and forth in the chamber.

          Siraniko


          • Siraniko,
            I have been considering the Anshutz ONE grip. I am very aware now of where I want things to sit and line up, I am thinking that I would like to touch the trigger lower now. I scalloped it out but now… maybe make it flat till I really know where I want my finger. It’s not exactly a four stance grip …. I think the piston weight was the issue. ??? If I preload from the trigger end with packers I can bring the preload up but not disturb the piston weight. Thankyou! Robert.


        • Robert,

          Looking good. Pretty creative on changing the trigger curve and LOP. I think with a conventional stock, the finger movement is more upwards (or wants to be). With a more vertical grip, a straight pull back is more natural.

          Your adjustments seem like they are working for you. The sandpaper was a good idea.

          I am not sure about the 10 mm (non)-preload. It should not hurt. Glad you nipped it and got a smoother shot cycle. You can always add washers or a spacer later to take up the 10 mm.

          Looking good,……….. Chris


          • Chris USA,
            Ah, yes, well conventional stock the hand is higher than the trigger so up and back makes sense. With my vert grip I do want to pull straight back and push the trigger in the vertical plane, hence the mod on the trigger. The sand paper between mated surfaces is Really GOOD !The grip has one screw holding it on and no locating pins etc, it is the sand paper that stops it from rotating. and it is solid. If I loosen the grip I can adjust to any angle, then nip it up. and I do not have to over tighten to stop it moving. It wont slip. Brilliant! So all mated surfaces get this now. The spring still has preload but much less and the piston is now lighter. I am only pushing 8.6gr FT pellets. More shooting and A/B testing the tow springs I have. Thank you! Robert.


          • Chris USA,

            Chris USA,

            I don’t see that in the attached image! Looks to me like a straight back trigger pull to me…it also feels like straight back when i hold the real thing…how you be holdin’ your rifle son?
            Can’t get too much more conventional:

            shootski


  8. It’s BB’s fault

    My day off. I was supposed to trim a lemon and fig tree. Was looking for a stone to sharpen a pair of shears and found a Diana 34 breech seal. Wait, my Winchester 427 leaks a bit and this seal fits. Went and changed the seal and no leaks. The trigger had a long mushy first stage and a hard second stage. Found instructions on how to adjusted it ( here on the blog). Now, I have a short first stage with a predictable and crisp second stage. Instead of prunning the trees, I have gone through two tins of pellets just to make sure I am not dreaming. Have not done laundry or dinner. Ubber Eats tonight.

    Thanks BB


  9. Gamo Modster last update before I call it for the night.
    This is why is charges so well. Custom nylon bearing. Cut and filed to fit a notch I filed in the lever connector bar. I polished the main tube. and grease it with some random RED synthetic wheel bearing grease. ( no idea if red grease is better…). and I get this really cute sharp little “click” when the sear over rides the piston and clicks into place. Every time. Actually you can feel the resistance go down slightly as you move over the hump of the lever progress. It’s that smooth. Glorious. I racked over a 100 shots last range night and it was a pleasure every darn time. : – ) Robert. PS. I think the next mod will be a really really special grip. Will think long and hard about it before I set to work. May look at other bolt on grips for inspiration. : -)



  10. To whom it may concern,

    SIG has shipped my SSG ASP20, .22cal., Synthetic WHISKEY 3 bundle.

    If you want one; SIG opens at 0830 EDT on Monday morning. I’m not buying mine for a collection it is going to hunt!

    I think NIB collecting should be banished! It should be discounted not valued, JMHO.

    shootski



      • RobertA,

        There are folks out there that buy things and when they arrive at their caves they take them still in the never opened box and put them into their deepest and darkest Lagers for storage!
        Then at some point in the future, most likely many years later, they take them out of storage and sell as: NIB (New In Box) for ridiculous price mark-ups. Can you believe such a thing?
        Of course there are worse creatures! Those are the ones that buy items up in quantities that are in small production runs and then FLIP them for way more than they cost from the maker.

        shootski


        • ShootSki,
          Oh I see. The cads. We call that something else over here. or at least we call them something… oh well. Jerks will be jerks. Like this one. I stopped for an amber light on a 80kph road. then it turned red. A car then shot past me doing over 80 through the red light. This was on the way back from Sunday shooting. Holy cow. I was very happy to arrive back at headquarters in one piece. We can put them with the NIB collectors… Glad to still be alive! Robert.

          PS. Scope was so far out ( took off then back on…) that I had to faf about getting back to shoot at 20m. And the rabbits were at 80m this evening…. need to get a scope with mil dots and practice various ranges… more work! : – )


          • RobertA,

            THE ULTIMATE OPTICS GUIDE TO RIFLE SHOOTING by CPL. Reginald J.G. Wales (CAF RET.)
            https://www.amazon.com/Ultimate-Optics-Guide-Rifle-Shooting-ebook/dp/B01974WENK
            This 180 page book walks you through each step of using your riflescope to its maximum potential. It is intended for shooters of all levels of experience and designed to bring your shooting skills to a new level. Complete with illustrations and full descriptions, this book uses real world examples and speaks in a language every shooter will understand and appreciate.
            This is an outstanding book that is a big help with one of our favorite topics.

            shootski


            • Shootski,

              Roger that! My 4×32 scope is not good enough to eyeball rabbits in the evening light when they are “ears back” on the deck. I had to keep swapping to binox to work out where to shoot!

              Will track down the book! Thank you! Robert.


              • Robert,

                You will like a mil-dot scope for hold over. Try to get something with windage hold off (aka: Christmas Tree”) marks in the bottom. You will be way ahead. I don’t know what you got down your way,… but UTG’s are very good quality budget priced scopes here in the U.S..

                Chris


                • Chris USA ,

                  Nikko Stirling Air King 3-9×42 Half Mildot With 3/8 mounts is $180 NZD.

                  http://www.nikkostirling.com/content/Products/AirKing/NGRA3942.html

                  I won’t be shooting further than 100m, I think the reticle will be fine. We have shortages of stuff at the moment for obvious reasons. If I can get this one before it’s sold I will be doing ok. I really do like my old Tasco 4×30 but I will keep that for 10m on my other sproingers . The extra magnification on the Nikko will help a lot with ID’ing clumps of grass and fluffy grey smudges. And range finding with the focus. : – ) That will make hold overs a thing! I don’t have a range finder and one more thing to carry is not welcome! Robert.


  11. PA chat said, “HW50 comes with delrin insert, and R9 has some other solution for the galling issue.”
    Another airgun vendor told that the HW galling issue was fixed in 2015.
    Has anyone here recently purchased either?


  12. Gamo bizzare-o-sproinger update.
    I decided to to some thunking over the trigger connector bar. 1911’s do the same thing essentially. The interesting thing is what happens when “because engineering”. For instance circles to strange things. You push on the edge of a circle with a stick and the stick moves way more at 90 and 270 than it does at 180 and 360. Sine waves. Reciprocating motion etc. In the diagram below you see the trigger bar moves from L to R. May as well be an engine con rod. The trigger itself is at 90deg to the Trig bar and may as well be an engine crank shaft. But the bar is captured in a slot and is not attached to the trigger itself. It merely is pushing it out of the way. So what so special? If you think carefully you will note that as the bar pushes the trigger it is slowly pushing at a longer radius. ( a crank pin revolution on a crank shaft has a constant radius ) this means the torque needed to push the trigger drops, it is being slowly turned into rotation. Ie. a short crank is very hard to push , a longer crank is easier to push BUT to get the same angle of rotation on the long longer you need to push it much further ).
    Hands up who has a very sensitive trigger finger? You can tell very quickly how hard or what kind of progress is being made when you trigger. If you are Olympic grade you could talk all day about triggers. So the question: do you want a changing rate? and this is where we get into exponents and coefficients. Then it’s turtles all the ways down. ( My Dad lived on them in St Helena back in the 60’s until he got “rescued”…. ) My point here is do not be put off by bits of wood, thread, glue, aluminum etc. Thought was applied here, it may not be looker but it does actually work very well under the circumstances. Frankly I would like to take the whole group out and frame it and stick in on my wall as a warning to others. “Engineers are not all looking in the same direction!”. A falling rate means feed back to the finger will be much less. Why? because torque goes down real fast the longer the crank is IF you are driving from the crank shaft. Engineering is very very interesting , may compromises have to be made at times. The balance is what is acceptable. Do you want a Tommy gun or a Grease gun? How many do you want and at what unit price? When do you want them? etc. : – ) Robert.


    • Robert,

      Interesting train of thought there.

      ” A falling rate means feed back to the finger will be much less. Why? because torque goes down real fast the longer the crank is IF you are driving from the crank shaft.” Mmmm? I would think the easier something is to pull (more leverage),.. the (more) feedback you would have, not less. I am not sure it matters much in your application though (with the linkage).

      I must correct myself too. For some reason,.. I thought the wood you added to the trigger was at your finger point of contact. I see now it is to improve the contact between your linkage and the trigger face.

      It is a bit hard to keep up with you at times,… with all of your out-of-the-box thinking and constants tweaks. 😉 The pics are a huge help in order to visualize things better! 🙂

      As for (changing) pressure/feedback/leverage,… I think? that is the way triggers are intended to work. I am no trigger expert by any stretch,.. but you want a trigger that is sensitive/predictable and not something you have to fight with. Leverage,… and even (changes) in leverage should help with that.

      Of course, nothing can make up for a bad design or a “lawyer” trigger. My Maximus trigger was much improved though with simple spring swaps/tweaks. Nothing changed on the parts/profiles. Again, no expert, but I would say a lot of airgun triggers could be drastically improved by simply using lighter springs.

      Chris


      • Chris USA,

        ” ” A falling rate means feed back to the finger will be much less. Why? because torque goes down real fast the longer the crank is IF you are driving from the crank shaft.”

        Mmmm? I would think the easier something is to pull (more leverage),.. the (more) feedback you would have, not less. I am not sure it matters much in your application though (with the linkage). ”

        Well it’s like this, if you make your lever too long it’s very easy to pull ( and you will pull a lot of it ) and the feedback will be significantly reduced. Think about a really long lever and even a block and tackle to pull it. will you feel the changes? Not really. It will be super easy to pull though !!! .

        Imagine a rod. with a spring on the end, you push the rod and it compresses the spring. You have a directly proportional feedback system.
        It’s 1:1. if you had two springs, a hard one and a soft one , you will feel the soft one compress, coil bind, then the hard one will start to compress. Springs also get harder to compress as they compress. Is it linear ???

        Now put a lever on the end of the rod. Change lever lengths etc. Your feedback is not 1:1 anymore. it’s a random division of it. Add a lever to the other end. maybe with a cam ( with an egg shape profile) Now things are getting out of hand! What kind feed back will you get at the trigger end? and this is essentially what trigger groups, clocks, winches, block and tackle, vices, etc all the same. They divorce the user form the actual work being done! Try a bow and arrow with your fingers, it’s as direct as you can get! but holding 200 pound bow string with your fingers ? No way ! Enter the “mechanism”.

        Sorry to harp on.

        If you have a long crank if you push it against a small load it will have a perceived fraction of that load at the end of the crank, you will have to push a certain way to push that load a fraction of the crank travel.
        This is the crank trade off: Less force but more travel. Pull out a nail. The nail travels n mm the crank end travels much more than n mm.

        Oh my gosh I am frustrated science teacher.

        The best triggers I understand are ones that use the “dead fall trap” type of idea: yank the small stick out and the trap load collapses ( using gravity ) – taking the sear with it – letting the piston go. The work needed to yank out the small stick is very small. It all has to happen very fast and not be too complicated. The yanking work can be a small compressed spring. If I was to design a trigger this would be my design starting point.

        The really tricky part is , not too sensitive to shock, has safety bits built in, resets itself, and wont; wear out too fast ( if ever ) . Holding back a strong spring is always going to involve at least two levels of mechanism , a heavy one and a light one. How they work together is the magic sauce.

        My biggest regret with my gamo is the trigger group. It’s just 100% mashed potatoes…

        oops A book! Robert.


        • Robert,

          Well, you sound like you have a good handle on the matter.

          Hey,… I like mashed taters!,……… but not for a trigger. 😉 I bet there is a way to get that trigger group better,.. but I will leave that to you. I would start by looking at the springs first.

          Chris


          • Chris USA.
            I was raised on mashed spuds , beef stew with peas, carrots etc and rhubarb crumble with custard. !!! woohoo!
            And I did good yesterday with some ok 10m groups. Was sitting in my camping chair though…. I reckon that could be a whole new discipline.
            50m camp chair shooting. ??? One camp chair, sit in it how you like. you may have a towel to use how you see fit ( roll it up as a rest etc ) Recliner deck chairs are OK , you can shoot prone on them. Using the chair solely as a rest is OK as long as you are using peeps sights.
            I am looking at amalgamating the theoben trigger group with a hammer. so the hammer kicks the bar which lets the sear drop. The trigger is literally only working the hammer. How the hammer is reset during cycle I am not sure, maybe the charging lever can reset it. OR have a pull back knob. It’s making a test jig to set it all up on to test and refine. That is the tricky part. and heat treating the parts. and getting CroMo steel… there is no rest for the wicked! ha. Robert.



            • Chris USA, Shootski,
              what I need is a really good springer trigger group to copy.
              Record ( Spigot ), Quatro ( Piston notch) .. any others ???

              That document will take a bit of digesting! Robert.


  13. Gamo sproinger news flash:
    Just found the target I shot at yesterday when taking back seats out of my car to make an urban hillbilly ute. Just got the scope under control after refitting it.Note the camp chair. No there is no berm or backstop, this is true, it’s sketchy but I keep things under control. Those Fig trees are quite a ways back. Robert. PS the 10 is a 15mm Dot at 20m shooting from the camp chair.


    • RobertA,

      You have a good shooting position. I recall one of the old blog members Wacky Wayne who BB got into field target shooting started out using his Wazy Boy as his shooting seat.

      Siraniko


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