Weihrauch’s HW55SF: Part 3

by Tom Gaylord
Writing as B.B. Pelletier

HW 55SF.

Part 1
Part 2

A history of airguns

This report covers:

  • Readers impact
  • The test
  • H&N Finale Match Light
  • Now, I zeroed the rifle
  • Sig Match Ballistic Alloy
  • Qiang Yuan Olympic match pellets
  • RWS R10 Match Pistol
  • But wait —
  • Summary

Today we look at accuracy. Because several readers have asked for it, I will re-test the rifle after I have tuned it. I have not decided yet whether I will do a full parts replacement tune, so there may be nothing to compare a Tune in a Tube tune to (say that quickly three times), but I will at least return and re-test the accuracy with the same pellets after I have quieted the action.

Readers impact

Several readers believe that making a spring gun’s action smoother will improve accuracy. It certainly won’t hurt it, but I have never found it to improve. However, I did an extra test today to see if I am doing all the things I can to get all the accuracy this rifle has to offer. We will get to that after the main test.

I am just an airgunner like the rest of you. I may have been doing this a little longer than some, but that doesn’t give me any special knowledge. From time to time I find it helpful to test the things I hold to be true. Today was one such time.

The test

I shot the HW 55SF off a sandbag at 10 meters. For the main test the rifle was rested directly on the bag. I used the same 4 pellets that were used in last Friday’s velocity test. This time I had my 1.25 diopter reading glasses and eye drops, so all was as good as it could be. Let’s begin.

H&N Finale Match Light

First up were the H&N Finale Match Light pellets. I didn’t know where the rifle was sighted, but since I don’t shoot it much I figured it would be pretty much on, so I shot this group without a sight-in.

Ten Finale Match Lights went into 0.378-inches at 10 meters. That number sounds small, but the group looks large when you compare it to other 10-meter target rifle groups I have shot. It wasn’t until the entire test as over that I remembered I usually shoot 5-shot groups with these rifles. A group of 5 of the same pellet from this rifle would be around 0.227-inches — if we consider that a 10-shot group is about 40 percent larger.

Finale Light group
Ten H&N Finale Light pellets went into 0.378-inches at 10 meters. Some paper tearing on the right side of the group makes it appear larger than it is.

Now, I zeroed the rifle

As you can see, these pellets landed to the right of, and slightly higher than the center of the bullseye. After this first group I adjusted the sights until the Finale Match pellets hit the center of the bull. I left the sights set that way for the remainder of this test.

Sig Match Ballistic Alloy

Next to be tested were the Sig Match Ballistic Alloy pellets. Ten of them went into a vertical group that measures 0.461-inches between centers. This target pellet is often one of the best, but not this time. I guess the 1968 Weihrauch barrel just wasn’t made for it.

Sig Match Alloy group
Ten Sig Match Ballistic Alloy pellets went into 0.461-inches at 10 meters.

Qiang Yuan Olympic match pellets

Next up were the Qiang Yuan Olympic match pellets. These have also done really well in other 10-meter rifles. The HW 55SF put 10 of them into a group measuring 0.267-inches between centers at 10 meters. Notice this group is also nice and round. This is a good 10-shot group for a spring-piston target rifle from the 1960s.

Qiang Yuan Olympic group
Ten Qiang Yuan Olympic target pellets went into 0.267 inches at 10 meters. Now, we’re talking!

RWS R10 Match Pistol

The final pellet I tested was the RWS R10 Match Pistol pellet. If you remember, these fit the rifle’s bore the loosest, and indeed, one of them fell out as I was shooting this group. I loaded a fresh pellet, even though it dropped on the carpet. Ten R10 Match Pistol pellets went into 0.195-inches at 10 meters. They are the clear winners in this test. But I did not stop there.

R10 Pistol group
Ten RWS R10 Match Pistol pellets made this 0.195-inch group at 10 meters. That white patch on the right of the group is just a paper tear. This group is as small as many 5-shot groups I have shot with 10-meter target rifles!

But wait —

There is more. Remember what I said in the beginning of this report? Several of you think that a rifle’s tune affects its accuracy. I am going to test that for you with this rifle, but I obviously can’t do it today. But, what if I have also been wrong about resting the rifle directly on the sandbag? I have learned over the years that lower-powered spring rifles often do their best when they are rested directly on a sandbag, but since we have the tiny group from the R10 pellets, we have the perfect baseline to test against. Would this rifle do any better if I used the artillery hold? That’s where I rest the rifle on the flat of my open palm and hold the rifle as loosely as possible.

The most stable artillery hold is one in which my off hand is held out near the front of the forearm, so that’s what I did. I wanted to give the hold every chance to excel. This time 10 pellets went into 0.686-inches, but one of those shots appears to be a flyer. It wasn’t a flyer that I called, but perhaps it was a bad pellet. The other 9 pellets are in a nice round group that measures 0.307-inches between centers. It’s small, but it’s much larger than the one from the sandbag-rested gun.

R10 Pistol group artillery hold
When I used the artillery hold I put 10 R10 pellets into 0.686-inches at 10 meters. Nine of those are in 0.307-inches. Nope — the artillery hold is not the best way to hold the HW 55SF.


We now know what the rifle is doing as far as power, trigger pull, smoothness and accuracy are concerned. The next step is to disassemble it to examine the powerplant parts, look more closely at the trigger and give the rifle a Tune in a Tube tune. Then I will report velocity again and then accuracy again with these same pellets.

We are spending some time with this rifle — mostly because you readers seem interested, but also to show you the innards of a 1960’s target air rifle.

60 thoughts on “Weihrauch’s HW55SF: Part 3

  1. BB
    I’m glad to see your different approach with this gun.

    Definitely see some difference even at the 10 meters.

    But when it comes to tune time it still could be hard to see the full potential of that paticular tune for that gun.

    From what I seen with tuning spring guns or any gun for that fact that it usually takes more than one disassembly to get the tune dead on. Some guns you got to dig deeper than others. Look at what Chris went through to get what he wanted out of his Maximus.

    So saying that. Even when you do tune this gun we are talking about today. You might hit the tune and make it more accurate or not. That’s what makes a tuning hard. Just doing something to a gun don’t always mean you done the best for it.

    • GF1,

      I really do not consider putting a regulator in the Maximus a “tune”. It just made it do what it already does, but just made it do it more consistently. Had I chose the 96 and did a 3000 fill out of the gate, then work would have been minimal.

      In fact, I did do a 120 bar. 110 bar is in between, but did not try that. Both may have been just fine with a 3000 fill. I would consider a tune to be more like adjustable hammer w/striker, different hammer spring, adjustable hammer spring/striker, de-bounce, bore out transfer port, etc..

      • Chris
        100% putting the regulator in your Maximus was tuning.

        You didn’t just put it in and it worked as you wanted did it.

        Just like finding the correct fill pressure and ending pressure on a PCP gun. That’s tuning.

        Of course you can just throw something in and fill it up and shoot. But with out trying different settings your not knowing what the full potential is. Once you adjust something be it a screw or a pressure and make it perform better you just tuned.

        • GF1,

          I suppose so. Really, it just seems like a no brainer cheat. You wanted one thing and I wanted another. At least we have some good data that will help anyone wanting to put a reg. in a .22 Maximus. If you can eliminate inconsistencies,.. that is always good. Evening out the fps is good. (of course, that leaves less and less “excuses” when do not go “as planned”.) 😉

          Send me the details on that new pump. Not that I need it, but it does have my interest. Yours is a whole bunch quicker, for sure. Hats off to you and the Buldawg for pushing limits,.. yet once again.

  2. B.B.

    When should one pick-up a pellet that has fallen on the ground and when should one use another pellet?
    I usually just pick them up and blow off whatever dirt may have stuck to the pellet.


  3. B.B.,

    As for tuning/smoothness/accuracy,.. I guess that a smoother shot cycle will just make it (easier) to shoot well.

    Examples would be PCP vs Springers, mild springers vs powerful cheek slapping springers. Smoother is just easier to do well with,.. without experimenting with special rests or hold set ups.

    Fine shooting by the way.

    Good Day to you and to all,…. Chris

  4. B.B.,

    No pellets with large skirts of the older classic RWS designs–Meisterkugeln, Superdome, Hobby, Superpoint, Super H-Point, etc.?

    I do agree that the tuning might not improve the accuracy, but it will most likely make it easier to shoot accurately.


  5. B.B.,

    Off-topic — you might remember the brand-new Walther LGV of mine that straight out of the box made a goose-like honk when it fired and also vibrated badly. I sent it to Umarex USA under its lifetime warranty. They sent it back with a note that it was working normally, that my LGV “is a 21 Joule [15.49 foot-pounds] model shooting 1200 fps. It is going to vibrate.”

    Yesterday I shot the LGV for the first time since it got back. Two 7.9 Premier Lights chronied 930 and 907 fps., an average of 14.8 ft. lbs. / 20.07 joules, but still twangy and vibrating. I cocked it for a third shot, but then it failed. It cocked normally, and the sear engaged, but the safety did not set, and the trigger will not pull past the first stage. I opened the breech and carefully removed the pellet with a wooden dowel rod. The spring is still compressed (!).

    I thought I’d seek your educated guesses before I call Umarex yet again. These shipping costs are adding up for something which is their fault first for poor factory QC and then for sending it back to me without really looking at it.

    Any ideas?


  6. BB

    This test really has my interest. My question about TIAT correlation to accuracy was the result of my experience with a Diana 34. When TIAT first was reported on this blog I ordered it and put it on my already accurate Diana 34. I reported here that the buzz almost disappeared and the sound dwell time cut in half. I was amazed. But the story gets better. Accuracy has improved using the same pellets from the same lots. It has always preferred two pellets; Premiers in the brown box, the first being 7.9 grain and measuring 4.53 mm head diameter, the second being 10.5 grain and measuring 4.50 mm head diameter. My rifle is balanced directly on a sand bag and I squeeze the trigger with a two finger squeeze (not pull). No part of me touches the rifle except those two fingers. I use a clear scope and there is no movement of the reticle during shots. Yesterday with no wind I got a 10 shot group at 25 yards measuring .259″ center to center with the 7.9 grain and just under 1/2″ with the 10.5 grain. Before TIAT I could expect groups between 1/2″ and 1″. The only difference is TIAT and the rifle aging.

    I hope you get similar results. I doubt that will happen with the R10 pellets because that group will be hard to beat or even to confirm. But the other pellet groups will be something I want to see also.

    Thanks for this fine report.


          • Yogi

            I replied much earlier but cyber space beamed it somewhere else.

            My shoulder does not contact the stock. Rifle sits balanced on bag and thats it for stability. Two fingers squeeze trigger/trigger guard. I look through scope but don’t touch it. Rifle and scope are heavy which helps to prevent wiggle.


            • Decksniper,

              I laid awake last night trying to figure out what your hold looks like. Still confused, nothing new there….

              Where do you place your thumb? How can you place your head in the same spot if your cheek is not touching the rifle. Don’t you get a crick in your neck after awhile?


              • Yogi

                I have been logged out with no password while travelling. Sorry for this late reply.

                I am very comfortably sitting in a chair of just the right height to look through my scope. The right thumb is behind the trigger guard. The trigger finger is on the trigger. These two fingers squeeze toward each other and enables good follow through for me after each shot. I did not invent this method. I picked it up from someone on this forum. I do suffer sometimes from familial tremor and arthritis in the hands. I can use the fingers of either hand for squeezing to help overcome this. Rifle is perched on my deck railing in the manner already described.

                You do raise a good point about not having a cheek weld. I am careful to set the reticle first before adjusting objective lens. I move my eyes up, down, right and left making sure parallax is gone or hardly detectable. Still it could be a variable I need to be mindful of.


              • Yogi

                I use this method for only the Diana 34 and sometimes my HW30s and Hatsun 95 Vortex. My only objective is getting the best accuracy possible. My CO2, multi pumps and single stroke pnuematics don’t care how I hold them. My other metal and gas spring guns prefer various artillery holds.


  7. Hi B.B.

    You were saying that there could be a 40% difference in size between a 5 and a 10 shot group.

    Are you shooting pellets sorted pellets or straight from the can?

    Just wondering how much of that percentage could be variance in the pellets. With a 10 shot group the chance of picking up bad pellet doubles.

    Happy Monday all!


      • BB,

        Was that 40% figure arrived at by personal observation or is it from a airgun/firearm study of some kind?

        Do you know of a similar number that can describe how one can expect the group size to increase as distance increases?

        P.S. Under READERS IMPACT did you want “readers” to be possessive? And in the 2nd sentence,same paragraph I believe you meant either, “…to get all of the accuracy…” or ” …to get the most accuracy…”

  8. Off topic question on HPA compressor filters…

    I recently got a AirVenturi 4500 air compressor as a retirement gift 🙂 and have a question about secondary air filtering (scrubbing).

    The compressor has a simple foam air filter built in and it removes a surprising amount of moisture and oil from the air.

    Do you thing that this filtration is adequate or should I be considering adding an aftermarket filter?

    I am looking at the Diablo ($200 USD) and the Alpha ($400 USD) and I am researching to see it there are other models available. Considering that the cost of the filter will almost double (exchange, shipping, brokerage, taxes) before I could get one in my hands, this is a pretty substantial investment.

    I just want to get an idea if I really need one or not. Any thoughts, comments are appreciated!


        • Hank,

          My Maximus was spotless on the reg. install. Check out the weekend report for details. I have the Shoebox 10 and post LP (5 micron) filter/pre-Shoebox which I have yet to drain a drop from. I have heard people say the drain a bunch with the Diablo. If that is true, then it deems some thought. I wonder like you, but so far, so good. It would be a piece of mind and if I ever drained a bunch of moisture out of it, I would be swearing by it.

          NICE! retirement gift by the way!

          • Hey Chris,

            I’ll check out your report on the Maximus regulator – I’m pretty interested in one myself. Thanks for the heads-up!

            I’m looking at a couple of filters and found a simple one that has a drain. Think I will get one of these as a 2nd level of filtration on the HP side to see if the built in filter is missing anything.


    • Hank,

      As you know, I added the Diablo to mine. Maybe I am being anal, but I am not concerned with water, oil or any particulates getting into my tank or my rifles. When I look at what I spent on my compressor, tank and HM1000X, the Diablo was cheap compared to possible issues down the road.

      • RR,

        Yeah, it was looking at your rig that put the stone in my boot – thanks buddy… but then, I’m bit anal as well 🙂

        Home HPA compressors are still a relatively new thing and a bit of caution might be prudent. Still trying to make sense of all that I have read.


        • Hank,

          That filter you were discussing with Chris may work. Providing a volume for the air to expand in and condensate form is a help and the drain will help you determine if more filtration is needed. A friend of mine added a small filter to each of his Shoebox compressors. Also, I was talking with Joe Brancato and he strongly recommends filtration. Now is the one on our compressors sufficient? Maybe, but I do not want to take a chance of ruining a two grand air rifle to find out.

          • RR,

            I have done some research on the Alpha from Joe Brancato and it looks to be a well designed, well thought out unit.

            Would love to have an Alpha but it would cost me about $750 Cndn/ $588 USD to get one. The replacement filters are $40 + shipping so that would put them at $90 Cndn / $70 USD. Its a Lamborghini class filter but too expensive for me. I am not surprised that Joe strongly recommends additional filtering 🙂

            I am looking at another solution that should work well. I’ll post pictures when I get all the bits together.


    • Hank,

      I also have this compressor and haven’t felt the need for additional filtration. My thinking , for what it’s worth, is that if it needed more it would have more, as shipped. Of course, if water and oil would damage the compressor some how, resulting in an earlier death and a shorter replacement cycle, they may have been tempted to cheap out on filtration. 🙂

      • Uh, Thanks HalfStep… I think 🙂

        Love the compressor – so convenient to have around, especially since the FX takes a 500cc gulp of 220 bar air out of my scuba tank. I really need to get a carbon fiber tank.


        • Hank,

          500cc at 220 is a lot of air! All my guns use 215 cc or less at lower pressures and I use a 85? cf fiber tank, and it’s great to have. The compressor is in an unattached garage and I wouldn’t want to travel back and forth anymore than necessary in the winter to refill each gun straight from the compressor or to refill something as small as a pony bottle. I would have gone bigger on the tank, but it was the largest PA sold at the time. Also, if you are interested, I have a 50% mix of antifreeze in mine and it cools fine. I’ve read some reviews that said antifreeze was too thick for the pump and the temp went up because of lack of circulation. I think they probably had a weak pump to start with.

          • HalfStep,

            My FX is a .25 caliber Royale 500 – hence the large bottle. Seems like a lot of air but I can drive over 60 JSB 25.4 grain pellets down range at 899 fps. The FX with its appetite and my 4500 psi Dominator were strong motivators in getting a compressor.

            My Weihrauchs are running off of 200 bar with a regular reservoir (250cc?) so there are no special needs there.

            My compressor is in an unheated garage and I am also running with a 50% mix of antifreeze. Like yours, the compressor runs fine with it.


  9. Charlie Da Tuna gave me a definitive answer on whether tuning will increase the accuracy of spring guns: Nope. Still, after, getting my rifles tuned, I can say it’s worth it.

    Having some difficulty on the knife sharpening front. I haven’t even been able to get to the chopstick and tape technique because I’ve gotten bogged down with my dressing stones. There is a pencil line on the edge of the stone that just will not disappear after hours of dressing! Unbelievable. Maybe it is in some kind of fissure, although the surface feels smooth. Unbelievable and time consuming. But I’m taking this personally and will grind away until it disappears.

    BIL, I believe you’re right about how good old boys would hunt tigers if they were introduced to control the feral pig population. In that case, the good old boys can load up for pig Ragnarok because the numbers say that the pigs will win without some radical intervention.


    • Matt61,

      I would imagine that the pig hunting might decrease as well, after a few hunters become tiger dinner. The hunter, becoming the hunted. Maybe a fun thought to entertain, but maybe not so much in real world application.


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