Mike is very close with the accessories IMO........I don't know what the arrow weight is for a 2315 !

I have chrono'd a loss of 6 fps for an Ultra nock and maybe 1 fps with a string loop (and they don't hurt nearly as bad if you clip your arm ) ! I have gotten a 2 fps loss on two different kisser buttons !

WV , My Outback is hitting around 272-274 on 70# 30" draw with 450 grain Axis 340's , with a WB rest , string loop , and a tru peep !
I generally see a 1 fps loss for every 3 grains with any of my last 4 Mathews ! So I would guess(like Mike) at about 240-245 fps for a 504 grain arrow with your accessories !
I'm currently shooting mine maxed on 75# and getting 282-285 fps w/ the Axis' (80 #KE ) !
I just didn't think string silencers made a difference so there's an extra 5 fps IMO !! And you can pick up a tremendous amount of speed with an arrow change..........my PSE CF arrows @ 350 grains shoot 298 fps on 69 # out of the Outback with a WB rest .......303 fps with a prong rest ! So the skies the limit.......however I am liking the heavier arrows and the trajectory difference between 300 fps and 280fps has been so minimal ......it's not worth mentioning !!