Canadian Airgun Forum

Following that a little polishing was in order, I started by polishing the sides (CA_10) and top (CA_11) of the links.

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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?

Then I gave some needed cares to the cocking shoe, it was pretty rough, see picture CA_12. All the edges were smoothened and polished (CA_13), and I filed and polished a radius on top of the shoe (CA_14).

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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?

There was noticeable flexing of the lever when cocking the gun at first, so I reinforced it by first tack-welding together the two stamped halves of the long link, about 1'' from the cocking shoe, see pictures CA_15 and CA_16.

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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?

Then the pivot hole in the lever was bored out to 3/8'', and a tight-fitting mild steel bushing was made (3/8'' OD, 6 mm ID), see picture CA_17. The bushing was then nickel/silver soldered in the bored-out hole, and the lever was cleaned-up and cold-blued where there was sanding done, see CA_18.

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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 first installed the lever and tried to close it. It would hardly go to the closed position and wouldn't stay clipped. The re-inforcing of the lever don't allow any binding now, so much so that I had to shave the back of the breech seal to get the lever to close normally again lol!

The lever was re-installed with tungsten paste on the pivot screw, and I used some Permatex synthetic light grease on the polymer parts, see picture CA_19. The yoke of the short lever is a snug fit between the MDS side plates (CA_20), and now you can't feel the steps of the lever bracket when cocking the gun, the small delrin ramps do their job! The red arrows show the stroke of the link yoke, it'll stay aligned all along its course now thanks to the plates going further backward than the bracket. Also the repair on the lever doesn't show much with the action back in the stock (CA_21). Cocking is now very smooth but very firm at the same time, there's no more side-play in the links and you can't feel any flex.

Will be back with more.

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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?

good stuff...
yeah the cocking linkage on the B3-4 was always the down fall of that rifle
good to see you improved it

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"A candle loses nothing by lighting another candle"

Thanks!

My goal was to make the rifle safe and functionnal, but there's stil room for improvements. I'd love to build a sturdier latching mechanism for the lever, I'm guessing the plastic front sight/lever catch won't last forever . I'm foreseeing something with a hidden latch.

Also the sights and trigger could be better, as well as a few other details.The gun has so much potential for improvement, it's amazing lol! Right now, the next step is to check accuracy with different pellets, and go from there.

Cheers!

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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?

That plastic lever latch is a weakness. We read about lots of people having them break. The plastic will only flex for so long and cold weather might stiffen up the plastic and set it up for breakage. Mine has seen about 4-5000 shots and still functioning for now. When it breaks I might try the small magnet approach to hold up the lever. The older B3 variants had a spring steel band that did the job but the latching bands are not easy to find as an aftermarket item. I'm looking forward to seeing what you come up with for a substitute. A hidden latch like the TX-200 or HW97 would be nice.

My WF-600 example has a good cocking linkage so all I did was apply some moly paste and all was well. The linkage is straight and tight and the cocking motion smooth. The older B3-1 variant had a one piece cocking arm that required a longer cocking slot in the stock. The 2-pc linkage gives a nicer stock but can create a flexing/binding if things are not aligned.

The main problem I had was in the bore. There was a tight spot right in front of the receiver and another a little further down the bore. Some careful lapping with fine sandpaper removed the tight spots. A pellet now pushes smoothly down the bore without hanging up on snug sections. Accuracy greatly improved. This problem can also be common in the Chinese B18 variants. Hopefully you have an example with a good bore without needing bore tweaks.

Be sure to try some H&N wadcutters when testing accuracy. Mine also likes the JSB RS and Express with 4.52mm heads.

While I was shooting my WF-600 last night I got to thinking about the cocking linkage strength. I only have the one .177cal WF-600 (B3-4) but I have four .177cal Crosman B18 break-barrel rifles. Three of the B18s are wire spring tuned to various power levels (600-875fps) and one is a full power nitro-piston shooting .177cal at over 900fps.

The cocking linkage design on the B3 is somewhat similar to the B18 with both being 2-pc hinged linkages and each linkage section being made from a pair of flat bars. The B3 cocking foot slips into the sliding compression chamber while the B18 foot slips directly into the piston.

At first glance the B3 linkage appeared to be made of thicker metal. When I took the measurements the WF-600/B3 definitely came out thicker. I measured all four of my B18 rifles and they were all very close in linkage metal thickness. The B18 linkage is not only thinner but also longer in length for each of the sections. More length would increase the possibility of flexing. With that said, I have shot tens of thousands of shots through my B18 rifles and never had a problem. The nitro piston B18 Fury has a very stiff cocking effort from beginning to end but the linkage has done fine. I'm wondering if complaints about weak or wobbly WF-600/B3 linkages could be from loose/worn fitting rivets rather than being related to the metal thickness and design strength. As mentioned earlier, my WF600 has seen close to 5000 shots without a linkage problem. It cocks smoothly without grinding or wobble. Maybe the rivets are fitting properly on this example. The example airmec is reviewing seemed to have missed the welding stage on the long linkage section. I think my long B3 linkage was factory welded at the cocking foot/shoe. The long linkage acted as one solid unit when I had it removed last year. It's currently installed in the rifle so I can't inspect for other welds along the linkage length.

Here are some comparison measurements between the B3 and B18 cocking linkages.

Thickness across upper linkage (2 thicknesses of metal)
WF-600 = .248-.253"
B18 = .196-.201"

Front to back thickness of top linkage
WF-600 = .400"
B18 = .400-.407"

Short linkage length (pin-to-pin centers)
WF-600 = 2.70" (close estimate)
B18 = 3.04"

NOTES: The B3 linkage is still in the rifle so I had to measure as best I could for the short linkage length. The stock interfered with this measurement but I got it very close. I'm guessing the length for the long linkage sections would be greater for the B18 due to the much longer stroke length.

The actual cocking arm on the WF-600 is a hollow tube with reasonable metal thickness. My rifle has been tuned to 645fps with 8.18gr pellets and I have not detected any bending in the hollow handle. Rick has one tuned to over 700fps with no complaints. Hollow cocking arms seem to be the norm. I wouldn't be installing a .128" wire spring but my .118" is doing fine and I think Rick might be using a short .122" Crosman spring in one of his.

As has been mentioned many times, the WF-600 (B3-4) is a project rifle that can be made to shoot quite well. You might get lucky but it's usually not flawless out-of-the-box.

Here is a pic of the two different cocking lever systems used in B3s.
The B3-1 on the right on the first pic shows the single rod lever used in the B3-1 model. The fore end cut out is considerably longer than the WF600 in the pic.
In the second pic, note that the WF600 has considerable travel of the cocking arm before it engages the compression chamber/piston assembly as compared to the B3-1. The cocked position of the two guns reflect the starting difference.
My B3-3 has the two piece cocking arm identical to the WF600.

While I have filed and stoned the large lumps off of the lever sliding area in the compression tube on my B3-3 and WF600, there was no need to with the B3-1 as the lever of the B3-1 does not touch the compression tube. I have read that some custom B3 builders (we're not the only ones!) prefer the B3-1 cocking assemblies since they are so smooth.

As to the issue regarding the strength of the cocking arms, I have had no trouble with any of my B3s.
My B3-1 in .177 and my WF600 in .22 have "rebuild kit" springs in them. (36 coils of .118" wire). B3-1 shoots 730fps (800 with 7gr!), WF shoots 530. Both have about the same lever force. My B3-3 has a broken B18 full power (36 coils of .122" wire) spring with about 30 coils left. I flattened the spring end and dropped it in the B3-3. It shoots at 610fps. Cocking force is noticeably softer than the other two guns. Very nice shot cycle.

While my B3-1 shoots well with a full power spring, the WF isn't exhibiting the same shot cycle and feels "harsh". I may try a softer (Crosman) spring.

Btw -Great thread Francois!

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Theory is when you know how something works, but it doesn't.
Practice is when something works, but you don't know why.
In my shop, Theory and Practice are combined!
Nothing works and I don't know why.

Two lathes and too many projects

Thanks Rick and Todd!

It's nice to see experienced airgunners add to the thread!

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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 the next paragraphs I’ll speak about some improvements I did on the stock and barrel.

I noticed some rubbing marks into the forestock (picture S_1), on the bottom where the cocking link rides. This Chinese wood is not the hardest and I didn’t want to risk undue wear, so I drilled a shallow hole with a 3/4'' Forstner bit in the bottom inside of the forestock (S_2), made an MDS disc with a slope on one face (S_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?

Then the disc was glued in place with 3M spray-on adhesive (S_4). It sits about 0.010'' over the bottom and shall protect the stock from wear. Thanks to Tim aka lefteyeshot on the GTA for telling me he saw plastic discs factory-installed in older B3s.

Also, the front stock screws had a tendency to ''dig'' into their pockets, so I added thick steel flat washers that sit between the star washers and wood (S_5). These are sold as 1/8’’ steel pop-rivet backing washers, you’ll find them in any good hardware store, just need to re-drill the 1/8’’ hole @ 5 mm. You don't notice them when the screws are installed (S_6), and now the screws don’t go too deep anymore and rub on the cocking link.

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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?

The barrel needed some cares as well. At first I cleaned the bore with a degreaser detergent (Hertel) and a lot of patches, then pushed a few pellets through it. The pellets were hard to insert, and didn’t like the factory crown at all (B_1), they actually got out of the barrel with their heads and skirts ’’shaved’’. I felt no tight spots in the bore though, and the lands and grooves are pretty well defined, so there’s hope.

To do a good re-crowning job (B_2) I had to remove quite a lot of metal from the muzzle. I used a 120° chamfering bit to remove the bulk of the material, and then used a 3/8’’ lead round ball wrapped in progressively finer sandpaper to finish the crown (B_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?

In picture B_4 you see the barrel leade-in as it was from the factory. There was a burr on the upper half, and the lower half looked as if there was something that hit it. I used a Dremel HSS cone bit (B_5) chucked in a small hobby chuck on the end of a 12’’ extension (B_6), to re-cut a clean leade-in, turning the tool by hand. I finished with 220 and 400 grit sandpaper rolled in a cone held in my fingers.

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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?