D-a,
Not to be a snit about it but I can not tell my shoulder angle, keeping it secret. Will say that body taper is very min, roughly 0.012" over the length of the case body. Can be tricky to chamber with such min taper, lots of time, lots of oil and mostly lots of patients to get perfect chambers.
Manson will make you a fine quality reamer, as will any of the other top name reamer makers, I use JGS exclusively and have never been disappointed.
I would highly recommend them.
Also, a live pilot reamer is the only way to go for extreme accuracy in a rifle. Also get a full set of pilot bushings or at least the ones you will need for your barrels bore diameter. Use as large a pilot bushing as possible while still allowing an easy slip fit into the bore.
Good Shooting!!
Kirby Allen(50)