Hornady's is a license built version of the RCBS unit so they are virtually identical. I prefer the Hornady unit and have my Uniflow mated to one. Others like the RCBS unit. There is a tube that screws into the bottom of the powder measure replacing the plastic piece the contacts the case when manually operating the powder measure. I forget whether the Hornady unit screws into the Uniflow. PM me and I'll check if you are interested.
It does. I use both company's case activated lowers....they both work fine.
BTW, both companies are mum about who licensed what, but here's what I think ...... based on more than a little obvious evidence....
The Uniflow predates the Hornady P.M. by many years......so the Hornady P.M. is probably a licensed build of the Uniflow.
RCBS did make a case-activated powder drop for their early progressive, but it sucked big time!
Hornady then made a very successful case activation unit for their AP, before RCBS even created the Pro 2000. RCBS added the Hornady version to their later Piggy-Back Rock Chucker Progressives. So when the Pro 2K came out, both companies were using it. So, my guess is Hornady licensed the case activated powder drop
to RCBS.....probably negating any payments to RCBS for using the Uniflow design......so I'm guessing they are now, "even Steven"!
Hornady also came up with a pistol case neck expander (PTX) for their AP, that drops in the P.M. Of course it also worked just as well in the Uniflow on my Pro 2000. Then RCBS finally came out with their own PTX that included an "M" style, 1/16" vertical bullet pocket, which was a huge improvement over the Hornady PTX. And....of course not surprising, the RCBS PTX works great in the Hornady......
Mr. Bullet feeder also used that pocket on their PTX's for pistol bullets on the Dillon Powder Measure.
Lest one thinks all these Hornady/RCBS parts are straight exact replacements.....you do have to change the linkage mounting locations on the P.M. to change RCBS to Hornady parts and vice versa. But it isn't hard.