how does the ar-10 in 300 wsm hold up and mag troubles?
The factory version is actually a .300 Remington Short Action Ultra Mag {RSAUM}.
Apparently, the mags and feeding geometry are a little tricky with the SP hunting ammo. Though a little fiddling gets it worked out – so I hear.
Ill let you know in about 3 months when mine is ready for a range report… 
From everything I know the neck angle on the 300wsm is not condusive to good feeding in auto loading rifles thats why you dont see any.
some calibers should be not used /tried in ar designs …thxs