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Panthera 22 reg issue (fixed)

weevil

Member
Dec 19, 2022
1,298
2,097
Utah
I posted a thread on my new Panthera 22, which morphed into a discussion on slugs:


Before it morphed, I mentioned that I was noticing some reg creep the night after I had tuned it to 133bar. Over the next few nights I observed that it was creeping up to 140. I decided to give the reg time to settle before getting too concerned but it was still creeping after 3-400 shots. Moreover, I noticed during shooting that the creep was actually taking place pretty quickly (45 min) and that the reg refresh rate was really slow. For example, taking a shot at 133bar would drop the plenum pressure to ~129 and then it would take 30-40 seconds to recover to 133. I’ve observed a few regs needing to settle in other guns but this was extreme, so I decided to dive in. Turns out that was the right call. Here’s what I did to fix it:

1. Removed the bottle and dry fired a few shots until the plenum degassed.

2. Removed the grip and then the trigger guard (3 exposed bolts plus one under the grip)

3. Screwed the reg adjuster in (CW) counting the turns so that I could get close to the set point easily upon reassembly. Careful to note the stopping point and not induce further damage by screwing CW past the stop. Reg was at 2.25 turns out.

4. Removed the reg adjuster screw by turning CCW until it popped out. Then removed the reg body also by turning CCW. That popped out with the piston and Belleville washers still inside the reg body, so no need to use the piston removal tool. Nice break!

5. Photographed the piston and washers and inspected the arrangement for reassembly:

3E06BFDC-C053-4B61-9579-88F1A35871B3.jpeg


From the base there are four pairs of darker, thicker washers in the arrangement ()()()()

On top of those, moving upwards, we have three lighter washers in the arrangement ())

6. Inspected all orings and found no issues. Wasn’t expecting any given that gun is new.

7. However, the delrin face on the piston was dimpled (sorry couldn’t take a good pic, really hard to see). That’s totally consistent with the problem.

8. Broke out the 3M Tri-M-ITE polishing papers (800-8000 grit) and proceeded to polish piston face, reg screw outlet and the mating surfaces of all bellvilles, going from the course to finest paper. Inspected all other contact surfaces (piston rod, etc) and found no issues.

9. Replaced bellvilles in orig. configuration, lubed all orings with silicon oil and reinstalled reg, setting reg screw at 2 turns out from the CW stop such that the pressure would be a bit lower than it was originally and could be adjusted up without incurring damage.

10. Replaced trigger guard, grip, bottle and gassed up to full 250bar. Plenum pressure/reg set point was 125 bar. Because this was a full 1/4 turn lower, I suspect that I actually had the reg set at 140bar originally and that it was taking 45min to refresh!

Results: Reg was subsequently adjusted to 132 in small increments made right after dry firing shots, to prevent damage. I then tested the refresh after shots and it is much snappier (4-5 seconds). It’s 1 hour sitting now and the reg/plenum pressure is exactly here it was before.

What’s the cause? Well, definitely not me! I’m super careful adjusting regs! Maybe the store and their insistence on setting it up and taking a few shots before I left? Asked em not to!!!! Or maybe the factory. Anyway, I love to tinker, so whatever.
 
Hi Scott. Mine would do that if I shot quickly enough. It was much better after the cleaning, but before I had decided to clean it, I had ordered a Huma reg. So, I tried it out when it arrived and it was even better than the cleaned reg so I left it in. It has bedded in very well after a little overnight creep, which is now down to 2bar after a few hundred slugs. The refresh is better but I still wait 5 seconds between shots. It’s inevitable with a 150cc plenum that refresh won’t be as fast. Bottom line is that performance is great with the Huma - see my post on Altaros slugs for validation!
 
Scott - also, I’m still wondering if the washer stack on the stock reg is correct (ie. installed correctly at the factory), since it’s a little odd. So, it would be useful if you could let us know how yours is configured - anyone else too. Seems like there are many users without this issue, so I’m wondering if there’s a few rogue stacks out there!
 
Funny, I just ordered a Huma reg as well, I will put it in when I work on the AMP reg. I'm a little upset I'm not getting the kind of consistency all the u tubers are bragging about. I have two Impacts and a crown that are heads and tails above the Panthera in shot consistency. I think I like the Panthera a bit more than the Impacts overall (especially if I can get this issue sorted)
Here is a picture of my reg stack as stock, not sure on what it's supposed to be.
20230420_202101.jpg
 
Thanks for this. I did this to miy Dynamic after reading this post and it seems to have gotten rid of my reg creep entirely.I also had a small dimple in my piston. I only had up to 5000 grit, so I wet sanded it to that as I didn't have anything handy that was finer. It seems to have worked perfectly though. This is how my Bellevilles were...

IMG20230903163434.jpg
 
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