Pft tuning question on a Prophet?

[igolfat8]

Aha. The one I'm having issues with is my compact. It’s always been very reliable and I have several thousand pellets down the pipe. Today I finished on 115 bar, 880 fps with 18s and 2.0 SD after 50 shots

I think the reg may need rebuilding this winter. I adjust the pressure up 10 bar, shoot a shot and it falls back 10. Increase it 20 bar, take a shot and it falls back 20. It creeps up about 10 bar when filled but after first shot it comes back and holds steady. Then when I am close to 50 - 75 bar before coming off the reg the reg pressure falls off 5-10 bar. I’ve never experienced these problems before or noticed them. My full size LR is as steady as a rock and never moves like this one. The reg holds pretty steady over night but I do see it creeping up just a few bar.

 

[Vetmx]

I had that exact problem with a RTI reg. As I was reading your post I started having flashbacks of anger and frustrations. Glad you caught it.

 

[igolfat8]

I had that exact problem with a RTI reg. As I was reading your post I started having flashbacks of anger and frustrations. Glad you caught it.

What did you do to solve your problem Vetmx? My full size Prophet's reg has none of these issues

 

[Vetmx]

I quit using their regs.

 

[Scotty1]

Vetmx, my Huma reg is back in its box here. I found it way too fussy. Just when I thought I had it settled in, I come back to an empty bottle. I like the original much more now…and it is pretty easy to service. My reg will creep overnight about 5 bar, but only with a fill above 200 or so bars, below that, no creep.

 

[Joedirt199]

I added a huma bottle reg after my RTI reg and run it higher than the RTI, ala FX double regged. It works well and did well for ZX10wall running a similar setup. It was an extra reg I had when I decided not to use it on a Kral Jumbo.

 

[igolfat8]

I’ve had my reg apart 3x over the last few days. First two times the reg still creeped up over night. Today I lapped the sealing surface with 1200 on a granite plate. Did the same to the Bellville washers and spring ends. Honed the bore of the spring as well as chamfered and polished both ends of the spring bore because the spring ID was scratching the piston shaft. Replaced the O-rings and assembled with silicone oil instead of silicone grease.

Shot a few hundred over the Chrono today with various reg adjustments and it seems to be holding much better but will verify again tomorrow to see how it holds over night. Phew this has been a frustrating few days.

If this doesn’t pan out then I will likely replace it with a Huma reg but don’t want to give up quite yet.