I picked up a 2013 bear grizzly that is 45 pounds at 28 inches.  My draw is 27 inches.  I have a dozen easton gamegetter 50 shafts that I got in a trade.  These shafts are full length.  I'm thinking of adding 100 grain brass inserts and using 125 grain heads so that I can use these with my grizzly.  Any suggestions on what length I should cut the shafts to get the correct spine for about 42 pounds at 27 inches?
			
			
			
				this could help you
   web pagehttp://www.youtube.com/watch?v=9cwWKJHFVPM (http://www.youtube.com/watch?v=9cwWKJHFVPM)