What is a good pellet weight for a Benjamin NP rifle?

[Mort Canard]

I have recently purchased a Benjamin Titan XS in .177 cal.  I have seen some arguments around the forum about not using too light or heavy a pellet and am wondering about the safe range of pellet weights for optimum performance of the nitro-piston.  I have a bunch of pellets around 8 grains and have ordered some Crosman ultra-magnum pellets at 10.5 grains.  Which of these are more in line for what the rifle was designed for? 

I am leaning toward the heavier pellets for the reason of keeping the ballistics sub-sonic and therefore less noisy. 

Thanks in advance!

[Motorhead]

8.5 - 10.5 range IMO

[OleTomCat]

^^ What he said....

[Mort Canard]

Sounds good! The Crosman ultra-magnum pellets at 10.5 grains should just fill the bill then.  Am looking forward to getting this thing sighted in and beginning the persecution of the critters.