hi chaps -- Bit confused regarding my HW80 in .177...

I chron'd it the other day several times just to check .. not bore you with the numbers but it is super consistant for an untuned gun , in my opinion anyways .
getting readings bang on power 11.8 ftlbs with only 10 fps variation over 20 shots over my F1 chrony.

Any ways that's great , so wondering way the heck is it so loud and why does it recoil and twang ?? if putting out such god numbers ... its very accurate too if I really do my part , in fact I was surprised but I do have to bench rest it and really get my game on as it is very hold sensitive.

Any ideas , should I just leave it as is , seems a shame to mess , thinking the piston and spring must be all good or it would,nt read so well

Thanks