That is really great I have never seen this before and honestly never thought Potterfield would put something like that out for consumption. Makes you really appreciate class people like the Brownell's.
So you just buy this barrel, a reamer and just chuck it up, drill it, screw the barrel back on and you have made your 223 'whatever' into a Donaldson Wasp sub MOA grouping machine — it's just that easy.
I have to agree with you. In general it is quite easy to change and fit an oversized hand but Mr. Potterfield is giving us a simplified version, while usually fixing the problem, there are a lot of little details that need to be known to do the job really right when the interaction of the ratchet and hand needs attention.