Finally have enough time pulling the handle to raise my first complaint. I love the press, but I now see why some were critical of the decision to bring the 550 priming system over to the new 750.
Being a rookie, it seemed genius to me, a marked improvement over having the 'ring of fire' spinning around in close proximity to the primer being seated. With the 'new' (old 550) system, it shuttles the primer over in isolation and mitigates damage in the event of a whoopsie....until it doesn't.
The damn plastic roller on the side of primer slide kept getting hung up on the assembly body for some reason related to the primer slide operating rod. As a result of hanging up, no primer is being transported to the plate because the primer slide isn't returned forward by the rod.
I tried all the operating rod adjustments, making sure the rod bracket was 5.625" in height, etc, etc...but every now and then, boom—the plastic guide wheel hands up and no primer is transported.
I read a lot of people bend the rod just right to push the guide wheel ("large roller") out away from the assembly toward the end of the pin it sits on, but didn't seem like a good fix...could see me jacking it up and having to put a call into the mothership from bending it too much/bad angle/etc.
Long story short, I think the whole operating rod idea is asinine and poorly implemented (I could see a track system/guide rod that doesn't bend and require constant alignments/tweaking.
So I tried taking a spare index ball spring and used it to push the wheel out so it cleared the assembly. Seemed genius...but the spring is a couple thou too big and gets hung up/binds in the little track on the primer slide...same result.
I then looked around for a narrower spring...only had a couple of 4.5# firing pin springs in my benchstock and didn't want to cannibalize one...but perfect diameter, if someone runs into this and has a spare around...
...finally settled on a spring from an old ball-point pen and enlarged it enough to get it on the slide rod/pin. Not my best work, but will grab a couple springs this weekend to have on hand, but this definitely fixed the issue.
However, I suspect me the operating rod will do battle later down the road. Just not a fan of it whatsoever.
Check out HF springs. One of the many reasons why some of us prefer the 650 priming system.