like the others mentioned - the pressure limits on this caliber are lawyer written more than anything else, however like reloading any caliber, you should still do a proper load developement. Start low and work your way up in small increments - i use 3 round test groups at 0.5gr increments and then make my decisions based on that.
lil gun will get you there, and its been very forgiving in anything i've used it in, but until you do the proper testing in your firearm - there's no sense heading right to the top and risking something silly happening. You likely wont find anything funny going on, but its always better to be safe than sorry. anyway - its an excuse to get to the range and pull the trigger a bunch of times, i mean that alone makes it worth the excersize