Does anyone have the patent for the Henderson Trimmer, or the Hornady?
Is it a single patent or a conglomeration of detail patents?
10 or so "Claims" and rough sketches.
What are the stated "Claims" of either.
Patent suits can be won or lost when "claims" are modified so the products are legally different; or when overly broad and already in the "public domain".
Guide rods would probably be in the "public domain" for machine tools.
Adjustment methods like a Locking nut vs a micrometer also.
I would, just for the fun of it like to read the patents as approved.
I argued with a patent attorney and the patent office over two patents.
The officials countered with ridiculous existing patent art and claims (some not possible without space aliens

). "My" attorney wanted loose, broad "claims" sort of daring others to challenge it.
Product went nowhere.
For years I used the Hornady hand crank
OAL trimmer. Even with a new cutter it left O.D. burrs.
A little extra time deburring the O.D. and of course the I.D.
I recently moved to the Lyman Case Trim Express
Neck Trimmer (Made in China

), about 150 bucks.
For some reason it does not leave burrs on the O.D.
I use a hand held I.D. tool that adds a couple seconds to each case.
Would take me a lifetime of seconds

to make up the price.