For a loopie, even 1/2 inch is strong, 5/8 or 9/16th of course is better. I can get the stuff uncoated for amazingly cheap...Just ask me, I'll get prices for ya. I'm getting some more soon myself, but I may be getting the stronger spectra. Coated is nice, but no big deal for a sling...as well, i'm gonna find out if I can buy some of it and coat it by hand...which wouldn't be as good as a factory coat, but should be fine.
If the sling is for use aloft, with 5/8 rope, a 3/4 inch Tenex eye sling would be better than a loopie. Or 1/2 inch if Plasma/Amsteel blue. The Plasma is very slippery and may need a more elaborate splice.. Nick?
If I find the time, I could send stuff to a couple of ya guys...
1/2 inch coated db is .53 a foot, for reference. But I think to get coated Puget Sounds Ropes, I have to get 600 feet.
What a nice day. We pulled over a 100 foot doug fir, in two pieces, branches and all, got 750 board feet of rough stuff...and a small 350 bf cedar...woulda been 250 bf more, but the specs called for a 12 foot habitat snag. Under 4 hours, $900 plus maybe $350 profit on the logs. Then we did a bit of of pruning for another client and neighbor, 1.5 hours for $375. Paid my guys each $240 for the 6.5 hour day, made 'em happy!