Hatsan Flashpup .25 60 FPE possible with Huma XXL plenum?

So I just recently purchased an airgun again after selling my Huma regulated Wildcat that I had years ago (I miss that gun, it was amazing...). Any who I really wanted to build something on a budget that could generate near my wildcat's powers to shoot some slugs out of it. My wildcat was tuned shooting 60 FPE with 33.95 JSBs for a ton of shots I don't remember exactly how many but close to 30 if I recall. Now I'm not looking for the wildcat's accuracy nor it's shot count as I know I won't get it. What I am looking for is to shoot these NSA 33.9g slugs that I bought @ near 60 FPE (58-60). If I can get even 10 shots with it with a low spread I'm happy and that's not a joke haha. So I purchased a huma regulator in the XXL plenum and I'm hoping to set it and forget it. Anyone with experience with this rifle want to let me know around what bar I should be setting it to? Hammer tension wise how many screws in? I know it's all relative every gun is different but a set point would be nice, I heard a guy reached 80 FPE so I know it's probably possible. Probably.. haha. Thanks everyone! 
 
Probably not. Really small tank in it. You'll need a big plenum. I had a Gladius regulated, I gave up a lot of power for accuracy. Was shooting 38fpe, went down to 25fpe with a reg.

huh... well that would be dissapointing.. I got the XXL plenum which is what he says is the power maker I guess but wow I would not be happy shooting a slug @ 25 FPE I got my marauder pistol shooting a .22 @ 30 FPE lol. 
 
I did what all great airgunners who can't figure out stuff do, return the gun and buy an Air Venturi Avenger...! Thanks all :)

I will be putting a 25cc plenum on my .22 avenger on monday when I have some free time.(stock is 10cc). In .25 I have no doubt that you can get over 60fpe. I am pretty sure it is possible with the 22 as well. I will post some results on here soon though. I think you will like the avenger more than the flashpup aside from the crap stock. I just made my own wood stock for mine.