I went on my first elk hunt this year and got a nice 6x6 at 25 yds...using a Sarrels 3 piece Longbow... shooting 50@28, I pull about 30.5" so around 57#?? I used homemade Doug fir arrows from Surewood, Grizzly broadheads(140). Had great penetration, basically pass through, found the arrow on the trail.... went about 100 yds or so... I was impressed with the penetration with the DF arrows and the Grizzlies. My arrow weight using the 80-85 spine was around 670 grains... the heavy arrow I feel was the key..Good luck