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PostPosted: Sat Aug 06, 2016 2:26 pm 
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Joined: Mon Jan 20, 2014 10:32 pm
Posts: 758
Location: Burlington ON
I have a new HW80K that is quite nice but pretty jumpy, twangy and loud, and all of these things contribute to inconsistency before we even start about whether or not I am just a rubbish shot anyway.

A couple of the guys have dropped Vortek kits into their TX200’s with good results so I started looking into “tuning kits” and researched TBT, V-mach and Vortek. I was planning to get a cheap and simple TBT drop-in kit, which is basically just replacement plastic spring guides. To order this, I would need to measure the spring ID to get the right set but even with a caliper there was no way I was going to be able to measure a difference of 0.3 mm as needed to order the correct size as once I got the rifle apart, I found the original Weihrauch spring wasn’t even straight, let alone measurable to this sort of accuracy (it wouldn’t even stand up on its own on one end). I therefore decided to go the Vortek route instead so I would get a complete new spring and guides assembly which I ordered from AGS. It’s the full power one so should be +20 ft lb, more than the 18 ft lb it was running originally. I didn’t particularly want more power but didn’t want to drop to 12 ft lb either with their lower output kit.

As well as the crooked spring, the insides of the rifle were pretty rough too so while I was waiting for the kit to arrive, I filed and sanded any burr and degreased the whole thing to wash out any swarf. I used citrus degreaser from Tire followed by an alcohol rinse to remove the degreaser and dry it faster. I thought this might be a bit better than just using paint thinner which often leaves a bit of an oily taint to everything. By the way, one of those small painting rollers pushed on a dowel and soaked in solvents is ideal for cleaning inside the piston chamber without risk of scratches.

The Vortek parts dropped in nicely but I made a mistake with the piston. There was a thin metal guide stuck to the inside that I did not see (or think was removable when I did notice it). This had to come out and although the Vortek instructions highlight this, it only eventually dawned on me just before I managed to completely wreck the Vortek guide trying to force it in. Getting that sleeve out was a challenge, I read the piston could be tapped on a block of would and it would eventually shift until a pliers could be used to grab it. That didn’t work so instead I sprayed it with WD-40 and used a box knife to lift it and loosen it from the piston wall. It then came free and I could grab it with the pliers. Incidentally, to remove the original piston seal, I ran it under the hot tap to soften it then wrapped a rubber glove over it and pulled it off quite easily. This seemed a better option to try than taking a screwdriver to it to try and pry it off (and risk scratching something important).

Everything was definitely now set for reassembly but after about an hour of sweating, swearing and cutting my hands to shreds I decided I was going to have to rig up some sort of spring compressor as there was no way I was going to get the end cap back on. I did a bit of research and came up with the contraption in the photo in about an hour using the jack out of the car and an old piece of 2x4 cut up and screwed to a larger plank. (I know this has been done before but anyway, this was the main purpose of this post – to pass on how to rig up a simple compressor but I digressed in the meantime…). Surprisingly, it worked perfectly. I didn’t even need the handle to operate the jack and could just turn it by hand to push the end cap back into place and turn it to pick up the threads. I have attached a photo of it all ready to go (you can see I am kneeling - to take the pic or praying...? You can decide).

The cap needed quite a bit of tightening and I used the same thing as I did to get it off: a wrench wrapped in shop paper pushed in the slot where the trigger assembly goes that I then whacked with a hammer. It took a lot of force to get it off to start with and a fair bit to tighten it back on and get the dovetails lined up. As it is, one seems perfect but I can still feel a tiny edge on the other side. I don’t want to overdo it so that will have to do; hopefully it won’t matter too much.

I then put the trigger assembly back on, this was not easy as the pins did not want to line up and I began wondering if I had damaged the cap. Getting the safety back on was also a bit fiddly but eventually it all went back together.

Next came putting the barrel back on which was a bit of an ordeal as you need 3 hands to do it, one to hold the arm and cocking shoe in place and one on each side of the pivot to push in the shims. Eventually I got the bolt in one side but couldn’t get it all the way through. A mallet didn’t help much and when I took it apart again I found I had damaged one of the shims by trying to force the bold over its edge. I took the shim out and whacked it with a hammer to flatten it (not the best idea as it was now dented too) and then used a large drill bit to chew off the burr that I had made. I thought I would hit a real issue here with having to source a new shim (reported to be hard to get hold of) but eventually I managed to get the barrel bolt all the way through, put the nut on and it does not seem any worse for the ordeal.

It was then a matter of putting the stock back on, which was slightly worrying as I found that the rear trigger screw had nothing to go into. I then found that there is a nut that is just pushed into place to receive it on the trigger assembly which had shifted so that was soon fixed and I had the rifle all back together.

Next, the moment of truth: it cocked, held the spring and fired. A big relief, I can tell you. It is seems to be a lot better, noticeably less jumpy and no twang at all. It is not easy to cock, that Vortek spring is a beast but it’s pushing pellets a long way into some spring compressor off-cuts in the garage. The big test will be when I can try it properly at the range next week. Meanwhile, I need to put the scope back on (and hope for the best on those dovetails) and then Loctite and torque the stock screws.

I can’t say I enjoyed the experience and hope not to have to do it again any time soon so it had better work out okay!

Anyway, the point of this was as I said to pass on the “how to make an easy spring compressor” bit, but I thought I may as well relate the whole story in case anyone gets anything else useful out of it.

Finally, I must say I am not particularly impressed with Weihrauch. Their OEM spring was a lot of rubbish and I resent having to pay another $100+ for parts to replace theirs in order to tame this thing and smooth things out. Maybe the pain will be worth the gain, don’t know yet but right now (and having thought I was a diehard Weihrauch fan), I am not sure I would recommend them all that much. I do love my HW45 though.


Attachments:
160806 - Spring compressor1.jpg
160806 - Spring compressor1.jpg [ 347.2 KiB | Viewed 786 times ]
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PostPosted: Sat Aug 06, 2016 2:40 pm 
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Joined: Mon Jan 20, 2014 10:32 pm
Posts: 758
Location: Burlington ON
Here is the "higher instructional value" pic of the spring compressor...


Attachments:
160806 - Spring compressor1-details.jpg
160806 - Spring compressor1-details.jpg [ 186.29 KiB | Viewed 781 times ]
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PostPosted: Wed Aug 10, 2016 6:24 pm 
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Joined: Mon Aug 13, 2007 9:04 pm
Posts: 712
I had the PG2 Votek kit put in my full power HW80K/.22 and it smoothed everything out real nice. JSB domes /Predators routinely go into the same hole when I do my part.If I recall I got 745fps or so.Grouse fold and drop even hit in the wingbutts........the new factory spring was bone dry and the seal had signs of dieseling burns.....Harold


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