Hw100 .177 with jsb monster 13.4gr

i was looking at the US version, ~24inch barrel is more like 22fpe max. Are you talking about the .22?

regarding Eds youtube video the 'Take 2', he should have detuned his .177 it to 17-18fpe and it would have been a lot better performer.
In my opinion- if you could get such where you are, I would prefer the 40cm barreled version instead.
shotcount will be a bit low, but nothing else to criticize really. Built like a tank differrent league to the most of the junk on the market

regarding heavy pellets, now you have another heavy .177 out ther the H&N sniper magnum 14.97grain!!
i can confirm both fit into the magazine, sorry i cant shoot at higher power where i am so someone else needs to chip in.
 
Thank you for your reply, the 60cm barrel is the one I have chosen, 30j is 22fpe, the same as Tes reviewed some time ago (in fact 4cm longer and heavier barrel, not the fsb version). I ordered a short barrel also to see which one suits me well but I think I will stick to the longest one because I could shoot faster without compromising autonomy. 

I don't want to tune it down, except some little adjustments to find the best speed 
 
That's great to hear, I want them to shoot has fast as I can under 990 that's the limit of the category that I shoot in ft here. I know that generally they don't group well at that speed but there are some exceptions, my steyr lg110 high power shoots very very well jsb 14.3gr even at 980fps but I would be pleased even if they group well at around 880-900