Morning ( again )
The DL Power plenum, yes, I have one here, it is the intention to make a video. 901 tuning has done a couple, will list them below. But an install video in my style may work with some numbers. This time I shall use chalk as apposed to Crayon, it washes away easier after mistakes. LOL.

Check out the 901 channel on 101 - Loads of tuning tips.

https://airgun101.com/index.php/channels/910-airgun-tuning-repairs

Thank you for the link. The video is helpful. I haven't adjusted the hammer spring tension yet, other than using the side wheel. I also shot some with the power wheel on "Low." The rifle shot well in this configuration too, so even though it definitely is not an Impact, it is still has quite a bit of tuning ability.

My next planned purchase is a .22cal conversion kit, and possibly a bottle & adapter.

Giles could you have a go at tuning a dreamline with a power plenum and keeping it sub 12 ft lbs. I would be very interested to see the shot string difference before and after power plenum. Also the amount of shots you can get.

I don't know that would work.....unsure.....maybe it would, maybe it wouldn't - have a PP here - my guess is not going to work....it should increase the amount of air in the plenum, but at a lower pressure.....science is a weird thing....my best guess is still no...but.........never know until you try....

I would love to try it just out of curiosity. Maybe there will be a better shot to shot consistency, maybe it will be inefficient. Only one way to find out. Not sure where I could get my hands on a PP here in the UK.

Will ask about PP for the UK, had someone else ask me to ask, so will chase the availability up.

Perfect thank for that Giles appreciate it ?

What I can contribute is that adding a PP to my DL .25 with the factory tune gave me an ave. 4% increase in FPS with both the JSB 25.39 and 33.95

I got mine from Huma air - I don't think its a an FX product though- the matt black finish is not the same as the Air Tube, but worse than that, when fixed the air tube no longer lines up underneath (6 o'clock) its more like half past 4 (looking from the stock end) and the manometer is no completely upside down!

I am not bothered about the finish not matching and as I have a air tube (Sureshot Aeron Dreamline) its doesn't really matter that it doesn't line up - but if you have a bottle dreamline - this would be a disaster as the bottle will be sticking out at an odd angle!

Presumably Huma are knocking these up somewhere without FX quality control standards?

Anyway I have a carbon bottle DreamLite arriving this week and 2 more plenums so I will be ranting here if my bottle prediction comes true.

With Regards to sub 12FPE - I have set my tube regulator to just under 50bar, added one 17cc plenum and wound my hammer out so that it is on 11.8FPE (very consistent on the Chrono).

I havent tested shot count yet - but with the tube off i had to dry fire it 7 times to empty the regulator, so that indicates good things.

I got mine from Huma air - I don't think its a an FX product though- the matt black finish is not the same as the Air Tube, but worse than that, when fixed the air tube no longer lines up underneath (6 o'clock) its more like half past 4 (looking from the stock end) and the manometer is no completely upside down!

I am not bothered about the finish not matching and as I have a air tube (Sureshot Aeron Dreamline) its doesn't really matter that it doesn't line up - but if you have a bottle dreamline - this would be a disaster as the bottle will be sticking out at an odd angle!

Presumably Huma are knocking these up somewhere without FX quality control standards?

Anyway I have a carbon bottle DreamLite arriving this week and 2 more plenums so I will be ranting here if my bottle prediction comes true.

With Regards to sub 12FPE - I have set my tube regulator to just under 50bar, added one 17cc plenum and wound my hammer out so that it is on 11.8FPE (very consistent on the Chrono).

I havent tested shot count yet - but with the tube off i had to dry fire it 7 times to empty the regulator, so that indicates good things.

What was the deviation like over a shot string? How many shots did you manage out of a fill?

My cheap Chromo only measures in whole meters but over 10 shots it did vary by 1MPS - so I don't thinks its its an issue,

I know have a Gen 2 DL (177) with 1 Plenum and a Gen1 with 2 Plenums (.25)