Might try a 1" Montana sling, best there is!!
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^THIS!^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
PM Scenarshooter here on the 'fire, they even done a bit of custom work for me, you see, I have this old pre-64 super-grade in 300 H&H, the original leather sling was getting very untrustworthy and NO ONE wants to drop their rifle.
I sent my sling swivels up to Scenarshooter, he sewed a nice new Montana sling around one swivel and tied their famous dog-knot? around the other swivel and mailed it all right back to me.
I couldn't be more pleased, and that rifle ain't gonna be dropped due to a faulty sling at anytime I may have left in my hunting career.
