Webley Mark II Service: Part 4

by Tom Gaylord
Writing as B.B. Pelletier

Webley Mark II Service
Webley Mark II Service air rifle.

Part 1
Part 2
Part 3

A history of airguns

This report covers:

  • Eley Wasps
  • JSB Exact RS
  • RWS Hobby
  • Observations

Today we see how successful my redneck breech seal fix was. I’m hoping for success, but even if it comes I won’t leave the gun this way. I will size the new seal and install it, or I will accept reader Komitadjie’s kind offer to make me a new seal of the correct size. Either way I will fix the rifle properly. This is just a chance to demonstrate a field fix that can be used in a pinch.

Eley Wasps

Let’s get right to it. First up were the 5.6mm Eley Wasps. Ten of them averaged 371 f.p.s. That is an increase from 308 f.p.s. in Part 2, so the redneck breech seal appears to work.

The spread went from a low of 355 to a high of 395 f.p.s. That’s a spread of 40 f.p.s. which is pretty broad. Based on that I think that, while the rifle may be doing better, it is perhaps not as good as it should be. Before we make up our minds, though, let’s see what some other pellets do.

JSB Exact RS

JSB Exact RS pellets averaged 325 f.p.s. in the first test. Their spread was 24 f.p.s., from 315 to 329 f.p.s. Today 10 of them averaged 373 f.p.s., but there was one anomalous shot that only went 199 f.p.s. The other 9 pellets averaged 392 f.p.s. with a 18 f.p.s. spread that ranged from 382 to 400 f.p.s. That anomaly bothers me, because even at 10 meters I think that one pellet would not go where the others go. The redneck seal may be experiencing an intermittent problem. So, there is more to consider today.

RWS Hobby

RWS Hobbys were the last pellets I tested. I didn’t test them before, but today they averaged 434 f.p.s. with a tight 13 f.p.s. spread from 427 to 440 f.p.s. That is very uniform performance. I think Hobbys may be a good pellet for this rifle.


First, there is now no detectable air loss at the breech upon firing like there was before. So the field fix seal I’m using at least works that well. You can put this fix into your airgunner’s tool chest for the future.

Next, I had forgotten how nice this rifle’s trigger pull is! This will be enjoyable to shoot, which I plan to do next.

Then there is the powerplant. I have no idea what it looks like inside, but when I ordered the breech seals I also ordered a piston ring. So I plan to open her up and take a look inside, after shooting for accuracy.

Webley Mark II Service piston ring
The Webley Mark II Service piston ring looks like any piston ring. The powerplant in my rifle may need a new one!

It occurs to me that closing the breech tightly against the seal is what flattens it. So I now store the rifle with the breech bolt rotated open, so there is no pressure on the seal.

I also discovered how the bolt works. I thought that the part that catches the rear of the barrel was somehow cut on an incline, and cammed the barrel back tight against the breech seal. But it doesn’t work that way. Instead, the bolt is threaded and when you close it, the threads draw it back against the breech, bringing the captive barrel with it.

Finally, I must observe that the Mark II Service powerplant is really a large pistol powerplant instead of a rifle powerplant. The piston is small and its movement is short. That means the swept volume of the rifle is very low. So, it will never be a magnum. I had no idea of what to expect before this test, but we may already be at the rifle’s peak performance.

We shall see.

48 thoughts on “Webley Mark II Service: Part 4

  1. BB,

    As you have observed, I also believe you have achieved close to peak performance without modifications. Polishing and crosshatching the cylinder and putting on a new ring may help a little. I believe GunFun1 was able to boost the power of his FWB300 some by using an o ring instead of the metal piston ring, but in your case I think I would keep this old girl original, most especially since you will not be shooting it much.

    I am curious as to whether the piston has a “rubber baby buggy bumper” on the end of it as the FWB300 does?

      • Funny, I did a redneck breech seal fix as well 🙂

        I had my “new” old Diana LP5 apart because the piston seal finally broke. So I fixed that and installed a new spring as well.

        As before, the gun was shooting high. So high in fact that I couldn’t adjust the rear sight low enough.

        The barrel is straight so that didn’t seem to be the problem. I figured the breech seal was probably flatter than it used to be so I flattened some solder wire and shimmed the seal with it. That was enough to get the pistol zeroed in, but the rear sight was still at the bottom of its range.

        Then I took a part of the hollow shaft of a q-tip, put it over the front post and painted it black. This seems to work fairly well. I am now nicely in the middle of the adjustment range. It also hides the pointy end of the front post which I don’t like very much anyway. The q-tip shaft might be a better match for the rear sight notch than the original 🙂

        I suppose I *could* order a new breech seal and an LP6 front sight. But redneck solutions are fun as well 🙂

        The non-magnum LP5 is amazing by the way.. I guess it deserves a full report 🙂

  2. I am wanting to go off subject here for a bit.

    I have a Hatsan showing up tomorrow and I am pretty sure I am going to want to replace the trigger adjustment screws. Can anyone tell me what thread and length I am going to need?

  3. I have had Mk2’s on the club chrony at over 500fps, so something is definitely amiss, I would imagine 430 to 470 dependent on pellet weight as in fine fettle, beautifully made but I could never get one to hit a barn door so that part of the test should be intriguing

  4. Since it has a metal ring a few drops of tranny fluid will help seal the ring. It will break the glaze off the ring and cylinder as you shoot. And not much tranny fluid. Maybe 3-4 drops at the most.

    Give it about 50 shots and then Chrony and see if the velocity comes up. It worked on the FWB 300 I had. Then of course as RidgeRunner said above the correct fit o-ring in place of the steel ring definitely improved velocity also. Just thought I would mention it.

    • GF1,

      Would a full synthetic be the ticket, or an old school type of tranny fluid? On the bi-pod, I got it converted back over from a pivot (to) a fixed. Been busy with other things,… so a day off from air gunning. Still killer hot and humid too. Will try to hit it hard tomorrow. Just a quick up-date.

      • Chris USA
        I would say the old school tranny fluid. We used it to hone out the engine cylinders when we rebuilt them. Put a little in the bores before putting the cylinder heads on too. And used it to hone out brake cylinders on the old drum brakes.

        And ok let me know how the bi-pod works out locked up.

  5. I’m glad someone is having success. I finished one of my roughest range trips ever. It never seems to get easier. But as a prelude, I really enjoyed reloading more perfect M1 ammo. My ogive lengths were within .005 inches! This is as satisfying as hitting a bullseye. The range was as crowded as I’ve ever seen it. It took me two hours just to get signed in. The staff couldn’t figure it out and believe that everyone is in a panic about the new California gun laws. Once I started, I realized that I had forgotten my arrows for archery and my .38 special ammo for my SW 686. The shooting itself went okay. My pistol groups are coalescing. I also managed to hit the paper with the .357 magnum at 50 yards including one pinwheel! One shot doesn’t mean a thing but it’s nice to see. Then it was on to the rifles at 100 yards.

    Here I found out that $200 worth of surplus .303 ammo that I bought is all useless! I never had a failure to fire but almost every single one had a slight hangfire. That made accuracy impossible, and it also raised the specter of my biggest nightmare which is a squib load that lodges a bullet in the barrel without my knowing. Then the next bullet I fire blows up the gun and me too. I figured if something was wrong with the primers, then something might be wrong with the powder as well. As a final desperate measure, I figured that I could shoot the rifle as a blackpowder gun, removing the bolt and checking the barrel for every single hangfire. But then I noticed some weird deposit in the barrel that altered the bore from being perfectly round. That was it. I had no alternative to dumping the whole load of ammo. Dressed up in my British web gear, I had nothing to shoot and was ready to howl with frustration, I can tell you.

    I think the problem is that the rounds came loose. I’m now done with any surplus that isn’t sealed in airtight containers and probably anything before the 1970s. As a final bitter pill, the surplus wasn’t even that cheap. I’m taking the advice about shooting with newly manufactured factory ammo more seriously. My re-enactment fell kind of flat. But I believe that in the Battle of the Somme, the British suffered because a lot of their artillery was of a substandard quality so their initial barrage did not do the damage that it should have. Maybe my re-enactment was authentic in the larger sense of disaster.

    I was consoled a little bit by shooting 7 clips flawlessly from my M1. Now that the follower spring is working properly, the rifle’s accuracy is pretty good. But the main joy is that functioning M1. Commentators have said that the action is like a symphony with all the different parts working together. And the boom of that recoil through the body is a positive joy. After 8 years of suffering with a malfunctioning rifle, I believe that I have set myself up for a lifetime of joy now that it works.


    • Matt61,

      Wow,.. I thought that I had frustrations. That day would put me over the top. I admire the lengths that you will go to on something,… even down to authentic period gear. Don’t think I will be going that far,.. but I still admire it. 🙂 What is appropriate “period gear” for a .25 M-rod anyways? 😉


    • Sorry to hear about your travails in the firing range. Two hours to sign in? How long after that to get to the firing line? Sad to hear about the .303 misfires and corrosive ammunition. Glad to hear that your M1 Garand has finally started to work properly. How is your accuracy with it?

    • Matt61
      Dempsey book best i’ve read on boxing! As he said most boxers (and other athletes, martial arts etc) don’t think about what they do, they just do. If they do think about it they often take their secrets to their graves. And the “teachers” so often don’t know what they’re talking about.

  6. B.B.,

    My inbox just had two comments posted by CptKlotz and Matt61,… and I had not even replied to either of them. It was their first comments. It just says that there is a new comment and shows part of it and then gives a link to click on that will take you directly back to the blog, in a new window, that then shows the comment as posted.

    Weird,…. just thought that I would give you some input from the user end of things. Let me guess?,…. they are still working on it? 😉 It’s all good.


    • RR,

      My laptop always flags miss-spelled words with a red under-line. Not sure if we even need a spell check. I right click and then it will pull up spelling options. It will even flag a word that is used twice in a row,.. the the.

      • It seems they have it set up right now so everyone receives a email notification for all responses made.

        On my phone at the very bottom of all the replies made there is the last spot to make a new reply. Right under the post comment box I have this. And hit has a box before it that you can check if you want it or not. I don’t want to receive all email notifications. Only the ones that are replies to me. So it’s unchecked until they get that part figured out. But here’s what I’m talking about.

        “Notify me when new comments are added.”

      • Chris USA
        I made a order today with Pyramyd Air. Guess what I forgot. Yep the Grizzlys. I just realized it when I was checking back to see if they got the blog correct.

        But ended up getting one of the Colt Pythons. The one that uses the same clips as the Brodax. So that means the clips I have for the Brodax will be extras for the Python. Plus the Python is supposed to have a rifled barrel. So interested in how it will shoot. But should have it before the weekend. I hope.

        And how did you lock up the bi-pod mount so the legs won’t swivel?

        • GF1

          Haha go figure. (Thats how my luck plays out)

          I made an order and forgot the h&n snipers I thought might be good fair for my new testing material.

          It all started out as a typical run for more falcons… next thing you know I had splurged…

          Let us know how that python works out for ya. I’m very curious about a comparison. Hopefully it lives up to, and maybe beyond the brodax. Although, I too, am disappointed about the lack of parts for your brodax.

          • PH
            Parts would be nice. But Umarex did say they would honor the 90 day limited warranty if I send the gun in.

            I think the Python should be pretty good. The rear sight is adjustable on it if I remember right where the Brodax has fixed sights. Plus I think the barrel on the Python is longer than the Brodax and it’s rifled instead of a smooth bore.

            I’m anxious to get it. And I still want to order the Grizzlys. I’m sure I’ll be making another order soon though.

            • GF1

              Yeah those grizzlies sound interesting. I am going to order some h&n snipers and a tin of piledrivers in a couple weeks. I’m interested in the way pellets will evolve into an almost different projectile as we increase power and push for distance.

              I would think the brodax is only a mere taste of what the python can offer. And all those extra clips… good thing you been exploring the cheaper crosman pointed pellets. That gun may develop an appetite. 🙂

              • pH
                Oh I know it will. Between the Python and the 1077 I’m going to be pellet pour.

                But still way cheaper than shooting my old Winchester 190 semi-auto rimfire .22.

                And the air guns are just as fun.

        • GF1,

          I just used a shorter bolt. There is the clamp and the pod. There is an O-ring in between the 2 mating surfaces. It works. The original set-up was a bit hokey. Pan was limited as well. The way I had with the bearing was very nice, very smooth and gave a full 360 degree capability.

          Bummer on the Grizzly’s. Cool on the Python. I really like the SW line. I looked real hard at (all) of them at one time.

          • Chris USA
            I will get the Grizzlys. I just plain forgot.

            So the bi-pod is locked up tight now. Remember if you happen to bump the legs it will probably change your shooting results.

            Interested to know how it goes when you shoot. Let me know.

      • Do knot uze spool checkering, knot shure who envyway. Pulse I grdumated furst in mie 3d graded klass in spooling. Evenly wun a spooling bee contesticle. Sew eye do knot reely kneed it. Shoot/rude save,

  7. Anyone interested in the big heavy Black Ops Tactical pellet rifle? Well there is a stable mate out called the Valken Infiltrator. It’s big, heavy, tight and chunky with the side mounted bibod. Evidently PA and many others are not planning to offer it. A side line offer from an Airsoft company. Same quality build material.

      • Yes they extend some and lock too but the pads appear to be plastic. There are no visible markings as to the actual manufacturer of the rifle but the instructions were printed in China.

        • A follow up … one web site selling the .177 Valken Infiltrator says it comes with a variable power scope, it does not ! Comes with a 4×32 fixed as pictured in the add.
          Also I found that Valken seems to be a ‘paintball’ company moving into the Airsoft and Airgun market. ( Hard Air Mag )

      • The rifle is a take-off of an existing bolt action L96A1 sniper rifle. It serves the same purpose as the mag, Just for looks !
        Airsoft people are into realistic copies of real firearms and this is just one item they included to capture the look. It is removable or reversible if desired. The bluing is outstanding, gas piston operation and the rails are metal. Not a folding stock but fully adjustable. A joy to shoot, very stable, very light recoil because of the rock solid stock weight. You either like it or not, but at least you know it exists now. Scope and rings are cheap standard issue items. It’s too heavy for a kids gun.

        • Err-umm…Tom, yes I agree with you regarding the operation of the bolt of the Webley Mark II Service rifle. But I was remarking on the faux bolt handle on the Black Ops Tactical pellet rifle which is patterned after the bolt action L96A1 sniper rifle.

          From the comment of Dom above it would seem a proper investigation of the internals is in order after your accuracy test. Will you be retesting the accuracy after doing the internal investigation/work?

    • Siraniko,

      Thank you for linking that. I think you (win the award) for posting the most relevant link related to the MSP discussion. Well worth the read, nice text and nice picture with shooting and chrony data mixed in.

  8. Matt61– When I get a lot of old millitary ammo, like yours, I pull the bullets (collet bullet puller) and salvage the bullets for reloading. Sometimes I have to put the bullets in my tumbler to clean them up. If the cases have Berdan primers, I discard them. If they are Boxer primed, I deactivate the primers by putting a drop of penetrating oil in the primer. One weerk later, it is safe to deprime the old primers and salvage the cases. In WW1, the British troops in mesopotamia were issued ammo that was labeled condemed, for practice only. Since they won, it could not have been too bad. Ed

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