Im looking at getting a new Ruger Safari Mag in either .458 Lott, or .416 Rigby. (I'm kinda leaning towards the 416 cuz I'm kinda nostalgic) The 416 holds I believe 3 and the 458 is 4 I think? Is there a way to increase the capacity of these? Maybe someone makes an aftermarket floorplate?

Note the ejection problem that the Rugers have.

The RSM is an excellent package for a factory rifle. Check it for function like any other rifle you buy before taking it afield. No factory or even custom rifle is 100% ready for the field when you first buy it. All have little bugs to be worked out and massaged.

Like anything else, the ejection problem can be fixed no worries. Just address it if it does happen to have that issue.

As of this moment, there're no sources for a deeper floor-plates for any RSM. Any rifle-smith will make one for you as a "one-off" custom floorplate. It's just going to cost you for his R&D. I almost had someone getting into fabricating some for all calibers in an RSM but he got side-tracked with a whole bunch of "black guns."

If someone comes up with a solution to more ammo in the magazine of a Ruger, it will probably require a new stock, or your going to have a hunk of magazine hanging out there and thats ugly on any gun IMO....If I wanted and extra round then I would opt for the 458 Lott and get an extra round and a more powerful cartridge, and I could load it down a good deal and still have a more powerfull round that a 416 in all probability...Don't they make that Ruger in a 416 Remington, that would be my choice....