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This might be relevant

https://castboolits.gunloads.com/showthread.php?107590-Payload-Substituting

and another useful discussion
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you can definitely load slugs into used hulls. Again, there is lots of info on the internet including Youtube how-to's. Google is your friend

Yeah Nah don't do that mate, a roll crimp is required, plenty of YouTube vids on how to and what it should look like. Go have a dig around and stay safe