CR600w Mods

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   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 - 10 Jan 2025 at 7:12pm

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Loud_Whisper Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 28 Sep 2024 Location: Auckland Status: Offline Posts: 9	Post Options Post Reply Quote Loud_Whisper Report Post Thanks(0) Quote Reply Posted: 10 Jan 2025 at 7:10pm
	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 - 10 Jan 2025 at 7:12pm

kruzaroad Members Profile Send Private Message Find Members Posts Add to Buddy List Senior Member Joined: 02 Jul 2022 Location: Hastings 4 now Status: Offline Posts: 2426	Post Options Post Reply Quote kruzaroad Report Post Thanks(0) Quote Reply Posted: 11 Jan 2025 at 8:54am
	From my basic understanding, and ive not looked to deep into co2. Its got a limit of pressure. Heat effects it. The push of co2 gives a higher fpe with larger cal. But i am assuming you need to increase volume for this.would also assume that being the case a heavier pellet of same cal increases fpe The bigger the bottle the more consistent the shot. The faster you shoot the more it cools itself and drops pressure. A longer barrel helps. As say i dont really know squat about co2 and thats just stuff that seems to be in the grey matter. Also rember a video where a guy sujested using special cylinders that had some sort of additive that helped to maintain the seals and lubricate the valves every half dozen cylinders. Walther made them I think. Though my tube of pellgun oil states its for co2 as well and does the same thing. You seem pretty onto it on the tinkering side. 👍

Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Forum Moderator Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1464	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 11 Jan 2025 at 9:42am
	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.

Loud_Whisper Members Profile Send Private Message Find Members Posts Add to Buddy List Member Joined: 28 Sep 2024 Location: Auckland Status: Offline Posts: 9	Post Options Post Reply Quote Loud_Whisper Report Post Thanks(0) Quote Reply Posted: 11 Jan 2025 at 10:28am
	Yep I've opened it up maybe 3 or 4x now. Last night I lapped it with sensodyne toothpaste while assembled and using the spring's tension. No change. At the same time I did remove those washers and shim the hammer spring differently, so it's now getting 13-15fpe. It just can't be left for more than an hour or 3, which makes casual bird shooting hard. What did you polish yours with?

Pauly5 Members Profile Send Private Message Find Members Posts Add to Buddy List Forum Moderator Joined: 10 Mar 2013 Location: Titahi Bay Status: Offline Posts: 1464	Post Options Post Reply Quote Pauly5 Report Post Thanks(0) Quote Reply Posted: 11 Jan 2025 at 2:34pm
	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.