.455 Webley is pretty expensive. And .45 ACP pressures may be too much for it. Personally, I would only shoot it with reloads. If he doesn't reload, here is a perfect opportunity to start.

He could get some .45 Auto Rim cases and start at the beginning load, and he shouldn't go a whole lot higher. I haven't checked it in a while, but I think most reloading manuals keep their .45 AR loads pretty tame due to conversions like your friend has.

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