Canadian Airgun Forum

Unfortunately the plastic OEM spring guide is prone to breakage. Too bad they didn't make it from solid material rather than the a fluted design.

Another interesting tidbit about the rifle is the trigger sear movement. The sear slides back in the elongated hole and is pushed down by the piston movement when cocking. When the cocking motion is completed the piston moves forward slightly and pushes the sear forward and into contact with the trigger engagement (holding piston back). Pulling the trigger removes this engagement and the piston forces the sear down but against the sear spring tension. Once the piston travels beyond the sear, the sear then snaps upwards because of the upward tension from the sear spring. This causes the sear to smash into the bottom of the spring guide. When you disassemble a B3/WF600 that has been shot a while you will see dents/damage to two spots on the spring guide. One spot is from the end of the sear and the other from one of the points on the sear bump. I would think a plastic guide would dent easily. Rick made me one from solid machined steel and it developed divots (see pic). Rick has some made from aluminum and they got beat up too but they are still very functional. I can't figure out how to prevent the sear abuse. A movement limiter pin might be possible but it would still have to allow the sear to reach the bottom of the piston slope.

Please correct me if my understanding is wrong on the B3 sear movement. I find this rifle very fascinating. Apparently it's been in production since the early 70s. It's sweet, quiet and almost recoilless to shoot so I seem to paper punch with it a bit every day (in basement). With 645fps (8.18gr) it's not exactly a wimp so 30-50 yard outdoor plinking is very possible.

I wonder if someone will ever manufacture a Super Deluxe B3. A Gamo copy trigger unit like in the B18 (Optimus/Phantom) should be possible with a simple Gamo style piston with sear notch. An upgraded stock style like the Optimus is also possible. The velocity on these rifles can already be tuned to non-PAL or made to shoot over 700fps. Accuracy is usually quite good and the rifle weight is only about 7.5 lbs with a light scope mounted. Even with the mentioned upgrades the rifle should still be $150ish and a great deal. Until then I'll keep enjoying my mildly modified WF-600.

CC_3 shows the somewhat rough entry of the chamber. To ease the passage of the seal when re-installing the piston I lightly polished the entry with 400 grit sandpaper, see CC_4 picture. I didn't removed all the machining marks, but I made sure to polish all rough edges. As I said earlier, the inside finish on the chamber walls is very smooth, with no machining marks left. The front chamber wall has a raw sawn-off finish, and I found another burr to remove around the TP. I used a 13 mm drill bit held by hand to remove the burr, I just needed to twist the drill bit 1/4 of a turn using light pressure to cut the burr off (no pics of that, sorry).

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

Rick and I once discussed the spring guide damage from the sear movement. Neither of us have tried it yet but the detailed senior's discussion resulted in the idea of using a chunk of hockey puck inserted into the machined guide. A hole could be hogged in the guide and the puck pushed into place and glued if needed. This hard rubber would cushion the sear blow.

In the pic you can see where the puck would be inserted (circled area). I also indicated the two spots on the sear that smash into the guide during every shot.

Interesting indeed! I'll keep an eye open for unusual wear on the guide and sear .



In the past I did graft a Crosman Phantom trigger unit on another Chinese rifle I have, that was relatively easy and well worth the work. I do have a complete brand new spare Optimus trigger unit, I'll check the feasability of installing it on the WF600. Thanks again for the great idea Todd!

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

Now I'll show you a mod I started to mess with a while ago, and so far it gave me very good results regarding the firing behavior of the airguns on which I did it. The original size of the transfer port in my WF600 rifle was a nominal 4 mm (same as on many Diana rifles), which I always found too big for my other non-PAL airguns. By experience I knew it could be downsized to 3 mm, so I machined a brass insert, threaded M5 x 0.8 on the outside and drilled to a 3 mm ID, 3mm in length, see picture CC_5.

Matching threads were made in the existing TP hole in the chamber, which was already of the right drill size for the 5 mm threads, I actually just had to run my tap through the hole without re-drilling. I installed the TP insert using red Loctite, @ 3 mm in length it sits flush inside and out of the chamber, see picture CC_6.

This TP mod moderates the added power that the new top hat brought, and smoothens the felt recoil. On the 3 or 4 rifles I already did that mod, it always yielded a better shot cycle. Many factors have to be taken into account when ''playing'' with TP size, everything must be balanced well together, but this is no rocket science either. I gathered much infos on the UK forums, but also here and there on the net.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

Last but not least in this section of the build, here's the work done on the piston and seal assembly.

In the picture PS_1 you see the piston as removed from the chamber the first time. Note the metal shaving embedded in the seal, probably from the TP. In PS_2 you see the piston and breech seal all cleaned-up, and both in excellent condition, I'll re-use both.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

PS_3 shows you the rolled-sheetmetal piston that seems standard in many a Chinese airgun. This particular one is well made, but dirty, I had to thoroughly clean the inside with coarse steel wool to remove the stuck-in grit. In PS_4 you see the piston head, you can see the nicely machined and finished spotwelds. In PS_5 you see the stamped-into-shape piston skirt, also well finished. I only had to gently polish the sear catch edge with 400 grit sandpaper, to have a better defined edge.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

Picture PS_6 shows you the original seal post with its screw on the left, and the new seal post I made on the right. Big thanks to TCooper for his reporting on the possible seal failure due to flexing of the seal when using the OEM seal post. Please read this for details, scroll down to the second reply by TCooper: topic92326-15.html .

In PS_7 you see the new retainer, its 82° conical head machine screw (M5 x 0.8, 12 mm in length), and the OEM seal. I carefully ground the moulding seam that was inside the seal (not easy to see in the pic), for a snug fit on the new retainer post.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

PS_8 shows the installed seal post with its blue-Loctited screw.

PS_9 is a hand drawing of the retainer post with dimensions. I didn't draw the screw hole as it may be made for a different type of screw, on my own part I drilled a 5 mm hole and chamfered with a 82° countersink bit until the screw head was flush with the retainer top.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

In PS_10 you see the seal installed on the piston, it fits tight and you can't feel any flex when pushing down hard on the seal face. PS_11 and PS_12 show the piston skirt burnished with tungsten-disulphide dry powder, you can see the grey-greenish shade it gives to the steel.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

In PS_13 you see the rear edge of the piston skirt, again polished with 400 grit sandpaper and burnished with tungsten. The sides of the piston seal and head were also burnished with tungsten (PS_14) and a light coat of tungsten paste was applied to the cocking slot in the piston, then the piston was installed in the compression chamber and the skirt was ''painted'' with a light coat of tungsten paste (PS_15).

Tungsten and molybdenum lubricants are so effective that you really don't need to apply much for excellent results. IIRC the manufacturer of the WS2 dry powder I bought mentionned an ''active'' lubricant thickness of only 0.0005'' is needed to protect the surface (when correctly applied). Less is better, and goes a long way .

More to come.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

I can no longer edit my post, there's a correction that needed to be made here:

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

In this part I'll be showing the work done on the cocking lever and cocking links, and also partly on the receiver. A nice fellow brought to my attention that he found the cocking arm to have a somewhat weak design on these airguns. Indeed there were a few minor issues to address in order to get a good and reliable functionning of the cocking lever.

To start with, I found that the primary link (the short one) was bent to the left, causing some damages on the side of the link yoke, as it rubbed against the end of the stock screw, see CA_1. Also the top of the secondary link (the long one) was rubbing and hanging on the front and rear edges of the arm bracket, causing some already serious galling, see CA_2 and CA_3.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

I solved this by first bending the link back to square, then I made some little ''ramps'' out of delrin, see CA_4, and some 0,050'' thick guide plates in MDS for inside the cocking lever bracket (CA_5). The bottom of the ramps is the same radius as the receiver. After that I sanded smooth the area where the link rubbed, see CA_6.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?

Next I JB-Welded the two small ramps in place and let cured for 24 hrs, picture CA_7. I then sanded the ramps so they follow the round profile of the bracket, see CA_8. Then I glued the side plates using 3M spray-on adhesive (super-strong stuff), in picture CA_9.

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If everything's so lovely yeah, then why don't I, why don't I, why don't I, why don't I feel lovely?