Pick one that meets your price and go for it. You are using them for gravers,,not their intended use as lathe tool bits.
As the latter they may get so-so reviews from a pro machinest, but I've yet to find any that didn't do a decent job as a chaser being wacked w/a 1oz hammer.
I like the 3/32 sq bits,,just a personal preference. Less material to remove in making/shaping a point. The slight difference in size makes a big difference to me when working with them too, not so bulky for lack of a better word.
With what you will encounter while cutting on most muzzle loaders you build, just about any HS Steel or Cobalt alloy bit will do, prefering the latter. Stays sharp longer and sharpens just as easy as HSS.
Lots of proprietary names for the different tool steels, but you are cutting mainly brass, CRS and 12L14 so it doesn't take much to conquer them.
I'd stay away from the carbide tool bits. Though they'll cut much harder steel than any HS tool bit will, they take special sharpening wheels and hones. They aren't the answer to all problems though.
If a gun or gun part needs carbide gravers to be cut,,then it's a miserable piece of steel for engraving to begin with IMHO. That from some one who has cut more Win21 receivers than I care to remember.
