To regulate, or not...

[MarkF]

I have a Gladius .25 caliber and I have a HUMA Regulator. My 10 shot group without the regulator is 5/8" at 25 yards using JSB King 25.4 gn. pellets. When I installed the regulator (set at 150 BAR) my shot group expanded 1.5" using the same pellets. This really annoyed me. I adjusted the regulator both up to 170 BAR, and down to 130 BAR and everything in between with very little improvement. (Yes the regulator is properly installed & vented, before you ask...) I tried several different pellet weights and brands and 35.8 gn. En Jin pellets worked best (1" group) but not as good as my original group. So, I thoroughly cleaned the barrel, valve, regulator and air cylinder. My chronograph is showing 734 FPS at 165 BAR with those heavy pellets. When the sun comes up I will see how she does at 25 yards.

Thanks for letting me vent on this annoying issue!

MarkF

 

[Birdo]

In mechanical equipment, sometimes less is best. I would remove the regulator and chalk it up to experience. You may have a speck of debris lodged in the valve or regulator that is causing the inconsistency.

Car analogy: The new Camaros can be had with a turbo 4 or a V6. Both have similar power, in fact the turbo may make better low end torque. All things be equal, the turbo is more probable to fail and cost big money before 200,000 miles than the V6.

 

[Skip-in-WV]

What was the pellet velocity before installing the reg? Maybe the reg is set too high? You may have to sacrifice some speed for accuracy.

 

[Erik]

I can't help but notice you never mentioned hammer spring tention (HST) It is VERY important to have the HST tuned to your specific reg pressure, you can go from a 20 fps extreme spread (big group) to a 4 fps ES (small group)

Play with your HST until you find the peak of velocity and then turn it down slightly to get the best air usage and ES then tell us your results.

 

[Menttaliist]

ErikI can't help but notice you never mentioned hammer spring tention (HST) It is VERY important to have the HST tuned to your specific reg pressure, you can go from a 20 fps extreme spread (big group) to a 4 fps ES (small group)

Play with your HST until you find the peak of velocity and then turn it down slightly to get the best air usage and ES then tell us your results.

That's a big point to keep in mind, and i hope that's the issue you're having. I remember when i was setting my Royale, i was having 35fps across 30 shots. Once i turned down the hst the ES was reduced to 12fps and increase 30fps my average velocity tightening the groups notoriously. I recomend you (like Erik did) play with the hst and check the chrony numbers. If they are right and you continue with the same issue, then... well i don't know
I dont see the reason to open the groups by just installing a reg if the velocities are not going crazy.
Good luck!