All those are .73” muzzle thickness. So thick enough to thread….they are already threaded 5/8s.
The barrels aren’t slow. The chambers are long. Results in lower than normal pressure with factory loads, which makes them a bit slow. If you hand load it’s an advantage. You can load out closer to the lands and pick up some bonus velocity over a standard throat and handloads loaded to close to SAAMI specs.
The factory magazine and BM offering is by far the lightest on the market of any gun type. I’ve seen minimal reports of issues with them. It is plastic and that bothers some.
To each their own.
I’ve had 2 clients lose tikka mags over the years on hunts in the field.