Nice arrows. I have been making arrows from boards and sitka spruce is a light arrow wood. The boards I have, I can't get much more than 35 to 40 pounds at 11/32nds. Now the Hickory arrows I made from boards spined at 75 to 80 pounds at 11/32nds.. The poplar spined at about 45 pounds at 11/32nds. Have some Maple I want to try and some Dogulas Fir. Your hooked Snag, LOL just have fun..
If you are buying your raw shafts, and you need more spine weight, then buy 23/64th shafts if you can get them. Then taper and sand them down to what you need. I make the spruce shafts at 23/64th, then I taper the end 9 inches on both ends down to 11/32nds. The 23/64th in the center adds a little more spine weight.