Regulated PCP Tuning Question

[30harry]

Assuming you can reach the same velocities either way when tuning, is it better to have higher reg pressure with less hammer spring or lower reg pressure with more hammer spring??

I'm working with my new 22 Avenger now and when It arrived from the factory the reg was set at 3,000 and the hammer spring was at 2 1/4 turns in and the velocity with jsb 18.13 was 914fps. I dropped the reg down to 2,700 and with the hammer spring at 3 turns in, I'm now getting 907fps with the 18.13.

Which is better or does it make a difference???

 

[Yo]

No matter what anyone says I personally rather go low on the regulator setting for more regulated shot count and less cocking effort via weaker hammer spring and probably less stress on the reg as well. Matter of fact And be discreet as possible during FLATULENCE just like the low setting on the regulator.

 

[mmahoney]

I also prefer to tune to as low a reg pressure as possible. Shot count goes up because the gun is shooting on the regulator for longer.

 

[JungleShooter]

I'm certainly pretty new to the tuning game, so here's what I've found (and read from others):



With the end result (muzzle energy) the same, my PP700 gets quite a bit louder when I tune it with a low regulator (REG) and a low hammer spring tenstion (HST).

This is not the case when tuned with a higher REG and a higher (harder) hammer spring — in this case the barrel/projectile gets only the shortest sip of air (sufficient because it is at a higher pressure).

Sure, cocking is a bit harder, the trigger pull I think might be also a bit harder.





Now an airgun eminence (Bob Sterne @ GTA/ HardAir Magazine) said that the most efficient while powerful PCP tune is that HST that gives you about 5% less muzzle velocity (MV) than maximum velocity (to be determined for each pellet—REG combination!).

And Bob says that if you (via the HST) tune the MV a lot below the maximum velocity (10% below, or much more yet) — then likely the MV will start to vary a lot (the "MV extreme spread" will be rather large) — and this contributes to vertical stringing (pellets hit high or low of the POA, due to being launched at various MV).



Anyhow, those are just some thoughts that might help.

Matthias

 

[Yo]

I would personally experiment with a 22 Avenger (If I trust it's reliability enough after waiting out for enough leak free feedback) after I buy one starting with the reg at 1500-1700psi to shoot 14.3gr Crosman Premier Hollowpoints and 15.9gr JSBs and Hades then bump it to 1800-2000psi for 18.1gr JSB Heavies and 21gr Baracudas. I probably wouldn't try to go past 2200psi max even if I wanted to shoot even heavier pellets or slugs. That's what I have Hubens and Sumatras for.

I would also fill it to only 3000psi max as with all of my PCPs due to my leak phobia.

 

[30harry]

I would personally experiment with a 22 Avenger (If I trust it's reliability enough after waiting out for enough leak free feedback) after I buy one starting with the reg at 1500-1700psi to shoot 14.3gr Crosman Premier Hollowpoints and 15.9gr JSBs and Hades then bump it to 1800-2000psi for 18.1gr JSB Heavies and 21gr Baracudas. I probably wouldn't try to go past 2200psi max even if I wanted to shoot even heavier pellets or slugs. That's what I have Hubens and Sumatras for.

I would also fill it to only 3000psi max as with all of my PCPs due to my leak phobia.

My original plan was to go for jsb 18.13 pellets but now I'm thinking I'll back down to the 15.89s and tune for that. I wasn't originally thinking it was going to be a 100yd airgun but from reports, it sure seems to do well there. I know it isn't my crown or red wolf. It's more a 50-75 max yards light pesting airgun with a really high shot count to me. I haven't found any field target around here but maybe is would fit right in there too. More testing required.

 

[30harry]

I'm certainly pretty new to the tuning game, so here's what I've found (and read from others):



With the end result (muzzle energy) the same, my PP700 gets quite a bit louder when I tune it with a low regulator (REG) and a low hammer spring tenstion (HST).

This is not the case when tuned with a higher REG and a higher (harder) hammer spring — in this case the barrel/projectile gets only the shortest sip of air (sufficient because it is at a higher pressure).

Sure, cocking is a bit harder, the trigger pull I think might be also a bit harder.





Now an airgun eminence (Bob Sterne @ GTA/ HardAir Magazine) said that the most efficient while powerful PCP tune is that HST that gives you about 5% less muzzle velocity (MV) than maximum velocity (to be determined for each pellet—REG combination!).

And Bob says that if you (via the HST) tune the MV a lot below the maximum velocity (10% below, or much more yet) — then likely the MV will start to vary a lot (the "MV extreme spread" will be rather large) — and this contributes to vertical stringing (pellets hit high or low of the POA, due to being launched at various MV).



Anyhow, those are just some thoughts that might help.

Matthias

I have seen while tuning from low to high HS settings that when using less HS, the velocities do seem to be more erratic and start to smooth out as I got closer to max HS with a specific reg setting. It's all a learning experience for me. I've already gone through around 2K pellets and haven't even shot at a target yet. It's all been over the chronograph.

 

[idoc]

Have you watched Steve's tuning guide?

https://youtu.be/2D_Zml_2wd4

 

[30harry]

Have you watched Steve's tuning guide?



https://youtu.be/2D_Zml_2wd4

Yes, at least twice and now I'll be trying a couple of his tunes. If it proves to be reliable enough this airgun is a game changer. If someone starts making precision replacement parts for this looks like it could turn into a 4 or $500 crown. . It needs better gauges first. You just can't trust the gauges at all.