The March issue of Rifle has articles onthe Nosler Custom48 and the Weatherby Vanguard Custom . It is obvious that the 48 is a Howa action. A few things that stand out are the integral recoil lug, the flat bottom receiver,the bolt is nearly identical with the groove cut in one of the 2 locking lugs, the bolt sleeve is different but the bolt handle looks just like the howa.
Nothing to really complain about here as Nosler has hit a home run with this one. The Howa action is outstanding. I'm a big fan of the Vanguards and to me the 48 is just a little too pricey so I won't be getting one.

I understand that Howa (back in the late 60's early 70's)copied the action for their sporter rifle from the Sako Finnbear. Some refinements have been made over the years and we have ended up with the Howa 1500, Weatherby Vanguard and now Nosler 48.