CR600w Mods

Yeah, I bought this used at around 5 years old I believe, so there has been a fair bit of wear and tear on it. I hadn't done any mods on the gun at the time I fixed the magazine slop above, but have since:
1) Bored all transfer ports to 4.5mm and sanded with P400(wet, and may re-do this) 
2) Drilled valve cavity to slightly increase shot volume. Around 3-5mm deeper (did not widen) and added washers to valve spring to keep valve preload the same as it was. This is to try and avoid worsening the already leaking poppet valve. (washers to be removed once leak is remedied and hopefully uncork it further) 
3) Mirror finished hammer and hammer tube, polished starting with wet and dry, starting at P400 and ending at P1000. Applied a 'very' small amount of graphite lube here.
4) Added 4x washers to increase hammer spring preload (approx 4mm)
5) Re-packed silencer using the 2x plastic spacers from my Hatsan 135QE + some woollen (?) blanket between spacer & can. Kept 2 of the factory "washers" in place.  
6) Removed trigger and pinched trigger housing together a few fractions of a mm. No shims needed! Lazy but free and gave an 80% improvement with 2 minutes of trial and error. 

Chrono readings from my android app are low and inconsistent versus what I'd hope for after these mods (9-12fpe, hoped for 15-18 based on Minty's experience) Waiting for arrival real chrono arriving next week from ali before I really dig into this but keen to hear anyone's thoughts. 

Next mods:
#Bulk fill of some type.
#Re-finish stock including a Co2 removal tool to stow in/under butt plate



Edited by Loud_Whisper - 11 Jan 2025 at 2:12pm

Good work. Have you opened up the poppet valve yet? I had one of these guns I'd bought as faulty and swarf had scratched the valve faces. It polished out, or I made a new one, can't remember, but it was an easy fix.

It would have been autosol. I think I used a wooden dowel that I shaped to match and used that with autosol.
I'll try and look up photos of the valve from when I did it.

Good evening,

No My bulk filled cr600 hasn't been for sale and probably wont as my kids have started to use it as its a perfect rifle to teach shooting and gun safety.

First you will want to make a dummy c02 cartridge out of aluminum with a 4mm hole drilled down the centre, fit this into the rifle (alot of marking and rechecking) then drill through the pressure tube into the dummy cartridge. Widen the hole in the pressure tube to accept a 1/8 bsp gass fitting.

Pull the dummy cartridge out then drill amd tapp to a 1/8 bsp thread for the fittings.
Re assemble and then fit you c02 bulk fill using paintball fittings, either with a remote line or fitted like mine.

Mine is a little front heavy but you can get different sized bottle or positions etc to get what you want.

This is it in a quick nutshell, I hope this helps.

Get yourself either thread tape or loctight rated for gas for all your joins.