I built a 416 Taylor several years ago...Midway A&B Savage threaded barrel and used Hornady dies.

Never had any trouble using Rem and Win 375 H&H, 416 Rem and 458 cases, sized and fireformed. Had to watch the belt thickness as it ran 0.205" to 0.218" between the different sizes and brands. And the case capacities also varied quite a bit.

The specs between the chamber and the Hornady sizer were very close also...about 0.002"-0.003" sizing just above the belt. Depending on the length of the belt and which one I used to set the barrel headspace, I had to use a Redding Custom shell holder of various thickness to get the 0.002" shoulder setback I like.

I rethreaded the barrel and installed it on an old Ruger Tang LA receiver, made a nut and matched it to the Ruger flat after headspacing it. There is sits today.

I shoot 20-60 rounds a year and it seems to just keep putt'm' right where I point...3 rounds usually touching...350 gr bullet about 1.5" below the 400 gr at 125 yds. Can't squawk about that performance...if only I could hold that well offhand.

For those interested there is a 416 Taylor site, http://www.geocities.com/bw_99835/, full of good information.

My 350gr Speer GS load exceeds the data for RL15 a bit, but the 400 Gr load is right on for C.Davids data(his page has now been moved/removed).

Luck with your projects.