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Weihrauch’s HW55SF: Part 6

by Tom Gaylord
Writing as B.B. Pelletier

HW 55SF.

Part 1
Part 2
Part 3
Part 4
Part 5

A history of airguns

This report covers:

  • Rob velocity?
  • H&N Finale Match Light
  • Sig Match Ballistic Alloy
  • Qiang Yuan Olympic
  • RWS R10 Match Pistol
  • Discussion
  • So, what?
  • Cocking effort
  • Firing cycle
  • Summary

Today we look at the velocity of the HW 55SF target rifle I tuned back in November. If you read Part 4 you’ll see that I just applied Tune in a Tube grease (TIAT) to the mainspring and got great results. Some readers ask me to use TIAT over and over again on different airguns, apparently not convinced that it works as well as it does. But when they break down and try it, they see for themselves. This stuff really works!

Rob velocity?

But what does it do to the velocity? This is a low-powered spring rifle and we know that thick grease can rob velocity. We have the baseline velocity data I gathered in Part 2 to compare to, so today I will re-test the rifle with the same pellets. Let’s get right to it.

H&N Finale Match Light

First up were H&N Finale Match Light pellets. Before the tune they averaged 613 f.p.s. and had a 31 f.p.s. spread from 594 to 625 f.p.s. This time 10 pellets average 608 f.p.s. and the spread was 17 f.p.s. — from 601 to 618 f.p.s. That’s not much of a decrease, but the spread was almost cut in half — a good start!

Sig Match Ballistic Alloy

Next up were Sig Match Ballistic Alloy pellets. These lightweight lead-free pellets are the speed demons in the 55SF. Before the tune they averaged 811 f.p.s. with a 16 f.p.s. spread that went from 801 to 817 f.p.s. After the tune they average 730 f.p.s. with a 31 f.p.s. spread than goes from 715 to 746 f.p.s. That is a significant change from before — a decrease of 81 f.p.s. and double the velocity spread. I will save the discussion for the end.

Qiang Yuan Olympic

I tested the Qiang Yuan Olympic pellet next. When I tested them before the tuneup they averaged 626 f.p.s. with a 17 f.p.s. spread from 621 to 638 f.p.s. After the lube they averaged 581 f.p.s. with an 8 f.p.s. spread from 576 to 584 f.p.s. The average was 45 f.p.s. slower and the spread was less than half as much as before. Hmmmm?

RWS R10 Match Pistol

The final pellet I tested was the RWS R10 Match Pistol pellet. This was the fastest of the lead pellets in the test before the tune, averaging 624 f.p.s. The spread at that time was 22 f.p.s., from 612 to 634 f.p.s. After the tune this pellet averaged 641 f.p.s. with a 20 f.p.s. spread that went from 629 to 649 f.p.s.


Let’s talk. The first pellet went almost the same speed after the lube as before. The difference was only 5 f.p.s., which is trivial. The velocity spread tightened up considerably though.

Both the Sig Match Ballistic Ally pellet and the Qiang Yuan Olympic pellet shot considerable slower after the lube tune — 81 and 45 f.p.s., respectively. And here is something curious — the Sigs doubled their velocity spread after the tune, while the Chinese pellets’ spread was cut in half! I can’t wait to hear what something thinks is going on there, because I have no idea!

Finally, the RWS R10 Match Pistol pellets were the only pellets that got faster after the tune. They increased by an average of 17 f.p.s. which is small but significant. The velocity spread remained about the same — 20 f.p.s. compared to 22 f.p.s. before the tuneup.

So, what?

I have a saying I have used several times in this blog. It goes, “Define the universe. Now, give three examples.” It’s a scholastic joke I heard in college. If you think about it, it can’t be done. It’s like an Escher print put into words. I’m saying this because I don’t think this data means as much as some people might try to explain. The rifle is now slower with some pellets and the same or faster with others. So what? As long as it is shooting fast enough to be a reasonable 10-meter target rifle, who cares whether it’s above or below 600 f.p.s.? You can pay $3,000 and get a target rifle that shoots nearly the same as this one.

If we were talking about a hunting rifle the discussion would be different. Then the focus would be in accuracy first, followed closely by power. But a target rifle only has to be accurate and pleasant to shoot, which this one now is. The TIAT has smoothed the shot cycle to near-perfection.

Cocking effort

There is one more thing to look at. In Part two I measured the cocking effort and told you it was 18 lbs. for most of the cocking stroke with a spike to 22 lbs. near the end of the stroke. In Part four I showed you what I thought was the problem (the broken flat spring that puts tension on the cocking linkage). This time I measured the effort as 19 lbs. though the stroke, and there was still a spike to 22 lbs. right at the end of the stroke. I’m now quite sure that it is the piston rod cocking the trigger. It came right at the point where the leverage is the greatest, and I doubt any adult will even notice it. I didn’t notice it in Part 4 after I test-fired the rifle several times to see if I’d put it back together correctly. In short, there is no difference in cocking from last time.

Firing cycle

On the other hand, this rifle is now a dream to shoot! It is almost dead-calm now, where is had an annoying buzz before. That is always felt the most during the accuracy test, which went well in Part 5.


This tune is great, and the rifle is still in the zone for 10 meter target rifles. I got off lucky this time because new parts were not required. Tune in a Tube, plus a little cleaning were all that was required.

57 thoughts on “Weihrauch’s HW55SF: Part 6”

  1. B.B.,

    A question: Did you fix the spring between the velocity tests?

    I agree that the affect of TIAT defies easy explanation. My first instinct was to look up their weights, but the two that were slowed were the heaviest and the lightest. Might the TIAT distribute more or less evenly after a few dozen shots? Some pellets might have been shot over your chrony with the TIAT distributed differently on the mainspring.

    For that matter. might the TIAT become a bit less “grippy” as it warms during a shooting session?


  2. I’m kind of thinking like DryCreekRob.

    And another question. Was the temperature different when you was testing the velocity verses this time?

    I know my air guns perform different on a cold day verses a warm day. And I’m talking feeling the temperature of the barrel.

    I can shoot a 10 shot group with the barrel and gun at room temperature still. Then shoot another 10 shot group after the barrel and gun has been exsposed to a 30° temperature for say a half hour or more.

    The colder temperature gun groups better.

    So maybe the metal of the barrel contracts and the pellet seals different to the bore?

    • Gunfun1,

      My FWB 300s will chrony perhaps 605 the first shot, and by the tenth shot, it’s shooting near 640. If it’s outside and a warm day, the temp increase from the basement where I store it (about 65 degrees in the summer), the difference is even greater. Shoot it 20 times and do not wait too long between shots, and it will send Hobbys out of the muzzle over 650.

      If it is an unusually hot day, however, I leave the springers alone. I get out my C)2 air guns and switch off from one to another. When I let each one rest after shooting it a couple dozen times, I set it on a folding table in the sun. That’s one more reason to favor blued and black air guns over nickel. :^)


      • Michael
        I use to see that in my 300 when I had the factory cast iron sealing ring on the piston.

        Now with the o-ring I have on it I don’t see that now like with the cast iron ring.

        My 300 is my most repeatable gun to just grab and shoot besides the Maximus.

        But I do notice a change with the HW30s and the QB79 going from room temperature to outside when it’s cold.

        And when I shoot from the breezeway the barrel is exsposed to the outside temperature. When I shoot numerous shots and set the gun down the barrel is definitely a different temperature than the rest of the gun. But my guns do tend to group better when the barrels colder.

  3. B.B.,

    That is tuff to explain. I do not think that ambient temp. played in as you were probably shooting in your office both times. I would be hesitant to say the grease is heating up due to firing. The distribution theory might hold up IF you had applied the grease the grease through the cocking slot. Instead, unless mistaken, you made sure the spring had a nice even coat of grease since you had the gun apart already. So yea,… in the end, no answers. Very interesting though.

    Good Day to you and to all,…. Chris

  4. B.B.,

    You mentioned at the end of yesterdays report that this is “the largest and most active blog in the shooting sports”, as you have mentioned before.

    Question: How exactly does one go about quantifying that? Can it show how many exactly from day to day? Can it determine where in the World the “hits” are coming from? East U.S, U.K, India?

    I am curious, as I suppose others might be,.. that are not as tech./web/internet smart as some here.

    Thanks, Chris

  5. BB,

    It sounds like everyone is going to overthink this, while I am just glad that the old girl still has it in her to take on the newer rifles. With all other possible variables being equal I am certain that the new PCP 10 meter rifles with all of their bells and whistles would outperform this old sproinger, but at the price those other rifles cost they had better. Also, the fun is gone out of shooting those. Those are way too serious to shoot, while this old gal is a joy to pull out and plink with for a bit.

  6. B.B.,

    The H&N Finale Match Light .177 Cal weigh in at 7.87 Grains. This behaved as expected with slight velocity decrease and tighter SD. The Qiang Yuan Olympic Pellets .177 Cal weighing in at 8.2 Grains went even slower and also had a tighter SD. The Sig Sauer Match Ballistic Alloy .177 Cal which weighed in at 5.25 Grains probably was just too light for this powerplant (possibility of being shot out of the barrel before the piston stops not getting the full push of air). Will be waiting for the accuracy test to see if the they will behave as predicted. Then again I could be wrong and the Sig Sauer Match Ballistic Alloy might be a good fit for this rifle.


    • Decksniper,

      My thinking is mirroring yours. One would almost be required to shoot multiple strings of each pellet before the
      the tune, then the same number in the same order after the tune. I ,for one, wouldn’t even have a guess at how many shots each would be required to make it statistically significant and there would always be someone who would say you needed 5 more.That’s a lot of work and if the gun is shooting well it would only amount to mental gymnastics in the end, anyway.

      • GF1,

        I filled my SCBA tank to 225 bar and hooked it to my Gamo Urban like I told you I was going to do. I’ll post a pic of the results so you can see what you think, but to me it looks like a good way to simulate how a gun would work on a regulator.

        I took photos of the gun’s gauge after every 5 shots to see when the pressure started dropping. ( I can blow the pics up on my phone and see really small movements of the needle.) The Crosman Ultra Magnum pellets were sorted by size and weight and I ran out after 90 shots. I thought maybe I saw a little lower pressure after shot 85 but I’m not sure.

        At any rate, if you compare these results with the Premier 5.48mm 14.5 gr group I posted over the weekend this group is tighter. That’s why I say it simulates a regulator. I’m going to try it at different fill pressures and I’m also going to try it with my Stormrider, which has a much, much worse power curve than the Urban does to start with.

        Tell me what you think.

        • Halfstep
          Cool. Looks like it worked out.

          I thought about that more over the weekend but wasn’t sure if it would work that way with out a regulator in line.

          I guess you have a pretty big air tank then. I imagine the bigger the tank the longer it would take to see the gauge drop at the end of a shot string.

          Just think what it would be like if you tryed a regulator in line on your big tank. It would take forever to see the gauge move if I’m thinking right.

          • Idaho,

            Look at the comments on Friday’s blog. About 2/5 of the way down the comments I posted a long, completely off topic comment about my impressions of my Gamo Urban vs. the two Diana storemriders that I’ve had. I think the velocity results for the 5.48 mm Premiers is the 4th or 5th photo I posted. It was a 40 shot string from a 230 bar fill of the gun’s reservoir.

            • Halfstep,

              I do have to say,… thank you once again for your real life comparison of the Urban and the Stormrider. The Diana name alone would have most people leaning towards a Stormrider. Your actual testing and (excellent) data representation have clearly showed differently. Pros and Cons aside, you did illustrate a valuable lesson. Things are not always as they may seem or what you would expect. Sometimes what would appear to be the underdog may just very well come out on top in the end. Nice work,… and I (do) realize that it has been work.

                • Mike
                  Thanks for the link.

                  I had looked at the data, but wasn’t paying attention to the group sizes.
                  Quite impressive with the right pellets. Nice to have that assortment.
                  That gun is a bargain.

                  • Idaho,

                    I do a pretty good “old and slow” myself so don’t worry about that.

                    If you are looking for the previous day’s blog ( which in this case, is what I was referring you back to) simple click on the blue highlighted link in the upper left corner at the top of today’s blog. It will have an arrow pointing to the left next to it.

                    If you are trying to go back a little farther than that, say 4 days, or Weds. post, look at the right hand edge of today’s blog and you should see a list titled ” Recent Posts” That is a list of the last 7 days worth of posts, including today. Click on the fourth one down and “BOOM” you’re back at last Wed.

                    If you need to go back farther still, keep your eye on that right hand edge as you scroll down. You will go past some Ads then a section called ” New to Pyramyd Air ?” then another section called “Categories” . If you stop here and click on a subject you will be given a list of blogs to choose from about that subject, but that’s not what you’re going for right now. For now keep scrolling down and you will come to “Archives”. Now just decide how far back you want to go. It goes all the way back to 2005, I believe.

                    Now, as for my groups, they are only 12 yard groups so they aren’t as impressive as they would be if they were 50 yarders, but they do represent the best groups that I’ve ever gotten from any of my guns, most of which are low cost entry level PCPs,Walmart guns, and a few German springers that I got in the late 80’s. I’m hoping that starting with holes that size at 12 yards will result in some close to 1″ at 50 yards. I won’t have regular opportunities to shoot at much longer distances than that.

              • Idaho,

                On the navigation part there is an archives section up near the top broken down by year and month and goes back to March of 2005, there is also a breakdown by category above that.

                Finding something specific can be daunting, but if you have the link to the comment it makes it so much easier.

                How do I get the link? Just click on the date stamp of the comment and your browser address bar will give you the link to that comment.


        • Halfstep,

          Very nice. I think your bigger tank is what you are seeing. The pressure in your tank dropped much slower than the on board tank would. Very nice test though. No regulator needed with results like that as long as you are willing to put up with a tethered tank.

          • Chris USA,

            Yeah, I’m sure it was the tank size ( 74 CuFt , I think). It was something that I proposed to GunFun1 over the weekend to test whether a regulator would be a worthwhile addition to the Urban. ( or any gun, for that matter) My feelings, now that I see my idea worked, is that although I got a more stable velocity it wasn’t enough better over the normal performance of the stock gun to worry about putting a reg in it. The stormrider has terrible air management so I want to try it next. I never intended to use either gun tethered all the time. Just saw this as a way to test before buying a regulator. Can also let you play around with what pressure to get the best result with different pellets. Don’t have to take reg in and out to adjust.

            • Halfstep,

              Yeah, taking one in and out to adjust is no fun, but not bad either as I found with the Maximus. 27 shots stock had a 100 spread and 27 regulated had a 12 spread. I’ll take that. For just using your on-board tank, I will say that it is worth it. Just do a bit of good research and see what other people are getting to reduce experimentation.

              The 100 was a bit of an up at the start, topped and then down. I think some of the nicer rifles have a regulator that is externally adjustable. Some of the power knobs that you see reduce the opening in the transfer port. Different, but another way to regulate air and power.

              Fun stuff and interesting stuff, but I really have little experience with regulators. I will say that I think that do like them overall. At the very least, it removes, or at least reduces another variable which is always a good thing.

              Another option to regulators is know what your gun does as it shoots down. Maybe hold a bit low as the fps rises, hold a bit high as the fps drops. Nail that and you have the same thing.

              • Gunfun1,

                I’m going to experiment with putting it on the bottle first, then we’ll see from there. You may remember me saying that I thought it might be shooting better as the air ran out and the pellets started flying in the 800 fps range. I think I’m going to try hooking the tank to it with just enough air pressure to give that speed and see how it does. Still got a lot of Winter ahead of me to experiment in.

                • Halfstep
                  Definitely would be a good thing to try the Diana that way. Especially since you have some info from the Urban on the big tank.

                  And yep I believe that makes a difference when you get the velocity right for a paticular gun and pellet.

              • Gunfun1,

                After talking to you this weekend I think I’m going to have a look at the crown also. Problem is that the silencer is held on with 3 set screws and they won’t come loose. It’s almost like they made it that way so you couldn’t take it off and use it on a firearm. The one on the stormrider I returned was the same way.

                • Halfstep
                  Yep you need to get that silencer off for sure.

                  Definitely check out the crown. Maybe even burrs down the entire length of the rifling.

                  Could make all the difference in that Diana.

                • Halfstep,

                  I tried to remove the muzzle adapter on the Hunter version of the Maximus. The set screw came out fine, but the adapter would not come off. I even used a strong heat gun thinking that perhaps some red Loc-Tite had been used. Keep us posted if you find something that works.

  7. The HW55SF looks to be a real nice shooter. Low cocking force, moderate velocity and pleasant to shoot would make it an ideal plinker.

    About TIAT…

    From all I have read, this TIAT grease warrants a close look. I checked last week but the local hardware store was out of stock and should be getting a shipment in soon.

    I commonly use Molybdenum disulphide (Moly-Slip, Heavy Tar, Velocity Tar) for metal to metal high pressure applications.

    I would appreciate comments as to how the TIAT grease compares to the Heavy Tar and Velocity Tar that I would use on more powerful springers (700 fps +) and the smoother, lighter Moly-Slip that I prefer for lower power springers. Thanks!

    Happy Monday all!!


  8. I also have a question about this TIAT grease. My sons have Red Ryders (4 of them) and I still have my first ever 1976 Red Ryder. I know these are low powered plinkers but I hate the “buzz” they produce when fired. Could this grease be used on even these low powered guns as well? Assuming I could get to the main springs. I know it’s possible to change one out, I just don’t see how since they look “pressed” fit together.


  9. BB

    I’m just commenting to ensure the title of most active blog is retained. Kidding 🙂
    I do think that’s an impressive thing indicating airgunning is taking off,and rightly so.
    There are so many reasons. Of course the quality of your articles plays no small part.

    So what is the typical effect of temperature on springers (velocity and spread)?
    And for PCPs – I’ll be breaking my PCP in around 32 F.

    • Idaho,

      Ouch! That is cold to be testing out and playing with a new gun. Cut yourself some slack on results,…. no one could shoot very seriously for very long in that temp. Looking forwards to hearing all about it though.

    • I’m starting to figure out how to find stuff in the archives so I thought I’d post the answer to my question.
      It does not expected velocity and spread, but at least I know PCPs are least temperature sensitive, followed by gas rams, springers being most affected. So it comes down to what my body can handle.


      I did aircraft maintenance in a former career, up on the Alaska highway. Forty below was not uncommon and we were flying DC3s that did not fit in our hangars. I really found out why all mammals that live in the cold have a layer of blubber. I would be dressed in layers looking like the Michelin man and still shivering
      uncontrollably, teeth chattering, hating every minute.

      Every one of the guys who had been there for a while had a “significant insulating layer” and could work in the cold, sometimes with just an insulated shirt, jeans, no long underwear, and often a bare butt crack hanging out.

      I have not acquired the insulating layer, so while 32F is not that cold my shooting will be limited.

      • Idaho,

        You are better off health wise without an “insulating layer”. I did see one fellow who went about 350# in just a quilted flannel give 5 people a battery jump in a 10 degree blizzard. No problem. That still sticks in my mind to this day, some 35 years later. Best wishes on doing the best you can. Hopefully that “warm and fuzzy” feeling you get when getting a new toy will keep you all warm and toasty! 😉

  10. I’ve owned a few vintage 10 meter guns and velocity/fps spread is irrelevant.

    The only thing that counts with these guns is accuracy. Extensive pellet testing with good form.

    I think B.B. threw the attractive airgunner bait today and got lots of bites!


    Seems Doug Phillips, stock restorer extraordinaire, has retired because of health reasons.

    A gifted woodworker and perfectionist whose work will be greatly missed.

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