Gen II .25 Marauder Owners Please Post Your Tune Specs

[Alex818]

I just purchased my first pcp, a gen 2 synrod and was hoping I could get you guys to post your tune specs (HS, HT, VS turns) and the your shot string. Also post if you have changed your factory hammer spring. I just want some samples to go by when I start tuning it. I have a chrony.

I intend on using it for hunting and would like to achieve 16 strong shots. I'm only savvy enough to change out the hammer spring but that's about it. I can't do other mods by myself. Please tell me if I should go with a 10 or 12.5 spring.

[RayK]

I intend on using it for hunting and would like to achieve 16 strong shots. I'm only savvy enough to change out the hammer spring but that's about it. Please tell me if I should go with a 10 or 12.5 spring.

Hi Alex!

Without doing any other modifications to your gun, your stock hammer spring will push your hammer energy high enough that your good shot string will be at a very high fill pressure.

I would start with VMS 5.5 HT 0 and HS 6 then shoot a string over the chrony from a fill pressure of 3200 psi measured on your best guage (usually the one on your fill set-up).

You want to see a rise from your starting velocity, up to a peak, then back down where it goes below your starting velocity. If it is a strictly decreasing velocity string, your hammer energy is too high and you must lower it. You can lower it by decreasing hammer spring preload or by decreasing hammer throw. Shorter hammer throw tunes tend to be quieter.

Ray

[Alex818]

Thanks Ray! Good information

[Nickdizonc]

I currently am running a hill modified valve with exhaust port opened up to 3/16, using the stock hammer and a 13lb HS. The HS is maxed out (Fully CW) and my HT is set to 6 CW from fully CCW. With this tune, I am able to sling the 43.2gr Eun Jin pointed pellets at 840fps. More than enough for my purposes.

[Nickdizonc]

I currently am running a hill modified valve with exhaust port opened up to 3/16 (barrel inlet opened to the same, and TP is opened up to .166). I'm also using the stock hammer and a 13lb HS. The HS is maxed out (Fully CW) and my HT is set to 4 CW from fully CCW. With this tune, I am able to sling the 43.2gr Eun Jin pointed pellets at 840fps. More than enough for my purposes.

[BlackICE]

I currently am running a hill modified valve with exhaust port opened up to 3/16 (barrel inlet opened to the same, and TP is opened up to .166). I'm also using the stock hammer and a 13lb HS. The HS is maxed out (Fully CW) and my HT is set to 4 CW from fully CCW. With this tune, I am able to sling the 43.2gr Eun Jin pointed pellets at 840fps. More than enough for my purposes.

Sounds like an awesome high power tune. What is your shot count and ES look like?

[Nickdizonc]

I'm getting approximately 12 shots at this power and ES on average has been about about 21fps.