Tuning Help to Tune Dreamline .22

[fiestaman]

Hi, I'm looking for help to tune my Dreamline. 22 with 500mm barrel. It came stock with plenum and superier liner as standard. It shoots the JSB 18gr at 880fps with reg showing 100bar on the fx guage. There is some small play in the hammer spring tension, about 2-3mm when set to max. I added a 2nd plenum and gained 12fps, ive also waiting on the Huma TP and pellet probe to match. My plan is to tune for a slug like 21-25gr H&N and hopefully I can drop the hammer to min or so and shoot the 18gr. 

But my question is how do I know what reg pressure to start with and how do I know what the desired speed is for the slugs and the pellets. Is it a case of picking a pressure and maxing out the hammer until I get somewhere near my desired speed and then back off 3-5% from max speed and that should be my optimum and fine tune from there? Can anybody offer some advice.

 

[L.Leon]

Seems like you know what you want to do and how to get there. Experimenting is the way. Somebody else's numbers won't necessarily work for you. You say it shoots the JSB Exact Jumbo 18s at 880 FPS. How accurately and at what distances? I would shoot it in its "out the box" tune a while. Establish a baseline, then tune away to your desired goal.

 

[wimpanzee]

lucky for you, there is an externally adjustable regulator! just play with it and see! different guns shoot the same ammo differently. What works at 850fps for one gun, might need 880fps to get the same results for another. I would recommend doing 5-10bar adjustments, shoot a few groups, then adjust again until you find the sweetest spot.

it's entirely possible you won't be able to get a fully optimal tune that handles slugs and pellets (with different hammer tension) the very best, but you might be able to get "pretty good". That last 10% of results is 90% of the effort!