Thanks guys, good suggestions all.
The Browning does ondeed come in the WSM chamberings, .270WSM, 300WSM and the .325WSM so the action will handle those pressures.
This is the easiest conversion I think going up to .358 or .375 with the .325WSM as the parent cartridge. It appears that some gunsmith/s in Oz already have access to reamers and dies for the two options above. I expect with the short action I will sacrifice the ability to take FULL advantage of the longest and heaviest bullets in these calibres.
The Browning at this stage does not come in the .376 Steyr and is more likely (I've made three wishes
) to come out in the .375 Ruger down the track than the Steyr but there is no guarantee of that...it's just conjecture due to a resurgence of interest I have noticed in the BLR; maybe due to the growing interest in lever guns in general. Don't get me wrong the .376 is a strong and respectable cartridge.
The .350 Remington has a lot going for it as well as an option except one (personal) gripe. It's belted. And while issues with belted cartridges may be exagerated, I can't help think that where there is smoke there is fire. And I need to simplify the reloading process and the cost factor (ie case life) as much as possible.