re-sealing and re-springing an HW30

[HOSPassassin]

Now that my hunting season is over it's time to do gun maintenance. One of my projects is to get my HW30 back into service.

The only work I have ever done on an airgun is to re-seal a Daisy 880 and replace an o-ring on a PR900. I have never worked on a springer before and I have heard that there are safety issues with the mainspring so I want to hear from people who do it.

I know I will need to buy a spring replacement kit. Do such things usually come with seals as well, or do I have to buy those separately? I'm assuming that everything ought to be replaced while I'm in there since I have had the gun for 5.5 years, shot it a lot, and have done absolutely nothing to it. It clearly needs work done because the velocity was found to be low when I finally got a chrono last spring, it got lower throughout the year, and now it has crazy 50-100 fps variations from shot to shot. That's unhealthy for any gun, let alone a Weihrauch.

What kind of lubricants will I need and where do I put them?

Will I have to buy special tools for any purpose? I have basic sets of screwdrivers and Allen keys in metric and SAE. I have heard that there is a thing out there called a "spring compressor" that smiths use on springers for the task of safely decompressing and removing the spring. Is that an essential tool or a helpful tool whose job can be done by something less specialized, like a vise?

Finally, is there a good video out there for this project? That's how I learned how to disassemble and repair my 880. Videos vary in quality, however. I want to watch somebody who does things safely and knows how to describe procedures clearly for a noob.

My goal is to restore it to a similar state as it was when new. I'm not trying to tune or improve it since I think it was practically perfect for a long time until this happened.

TIA,
HA

[Deerstalker]

My suggestion is a kit from these folks. https://www.airrifleheadquarters.com/page/page/251488.htm
and a piston seal from here.  http://vortekproducts.com/ourstore/Airgun_piston_breech-seals

This video should help you also. 

Good luck and be sure and take pictures.  Go slow and should be easy peasy.

I forgot to add that after a through clean/polish that you may want to use Krytox, GPL-205 for lube.

[TXKmike]

You can get by without a spring compressor but there is some stored energy there. You may have to search several videos to glean several points. I learned the most from 2lbstrigrpull channel but I don't think he has an HW30 video. Also it seems the European guns on youtube have about half the preload spring pressure making it easier to work on. My best tool is a brass pin punch, 1/8" I think. The HW30 has a small screw holding the trigger block / housing in, which holds back the spring pressure. I like to take out the cross pins first and replace one with a tapered punch, then take out the screw. Hold back some pressure on the trigger block to not damage threads on the small screw.

I used the same kit and seal that Deerstalker recommended. My guns velocity did not change from it's original kit parts but it got smoother and quiter. I think the aftermarket parts are a lot higher quality. The moly lube alternative is a thing to consider. You should definitely have a lubrication plan going in. I'm personally still learning and experimenting.

 

[EMrider]

A bit old, but I found these resources very helpful when I first tore into my R7s.

http://www.airguninfo.com/tuningther7.mht

https://www.tapatalk.com/groups/weihrauchowners/the-hw30-mk-ii-stripdown-t3865.html

Either an ARH or a Vortek kit (or a combo per DS's suggestion) should get your gun shooting better then new.  I personally use a sash clamp when working on my spring guns, but the R7/hw30 may be doable without one. 

Good luck
R

[byhsu]

for the HW30s you will be OK without a spring compressor, i opened mine up and it was easy just following some videos on youtube.  For  Piston Seal i like the Vortek, supposed to be made of a self lubricating material so will last long time.  Springs, I like the ones from ARH, a lot of customers report that they are long lasting and high quality.  For Lube, I use the Honda M77 moly paste, which supposed to be very good for lubricating the inside of springers, and you don't need much, will last you a long time.

[pgritty]

Maybe just a breech seal first. Might be as simple as that.
Pat

[sicumj]

I have to agree.  IMO you can't beat Vortek seals and ARH spring.   To check breach seal fire the gun with a tissue over seal and see if it blows off.

[Yogi]

I would strongly suggest getting a set of "hollow ground" screw drivers.  Normal screwdrivers do not fit the screw slots of the stock screws very well.  Thus it is easy to mess them up.
All other recommendations are spot on!

-Y

[HOSPassassin]

Update:

After much trial and frustration, my HW30 has been taken apart and put back together with a new Vortek piston seal. I inspected the breech seal and the original spring and did not see anything wrong with them so they were re-used.

This morning I did a chrony test to see if the erratic velocities had straightened out. 7 grain Basics shot at about 640-650 in 17 F weather. Is this about right? I'm thinking it could sniff 700 in warm conditions.

I tip my cap to all you tuners out there. It is a PAIN IN THE NECK to put the trigger block and the trigger unit back in so that all the screw and pin holes line up!