I'm loading for a S&W 500 and am using Hodgons data for loading the 370gr Cast Performance bullet using H4227 powder. Their data used Winchester LR primers and all I'm finding in my area are the CCI LR primers. I'm new to reloading (but not my 500) and will be staying towards starting loads for at least the first go around so pressure doesn't appear to be an issue. Is that a rookie mistake or is there a general rule of thumb about substituing primers?

Thanks,

Bryan

I think you'd be ok, from my understanding are the Winchester primers are a little hotter than the CCI and I don't think primers affect pressure all that much. As long as you work your loads up and watch for pressure signs you should be ok.

As long as you stick with the standard LR primers and don't switch to magnum primers, you will be OK when using the starting to midrange loads published in the reloading manuals. When bumping into the maximum loadings, switching primer types need to be gauged carefully in increment loading to assure things are kept within pressure boundries.

I have loaded both the 370 and the 440 Cast Performance Bullits in my BFR 500 and have used both WLR and CCI large rifle primers. I haven't done "extensive" testing but I haven't noticed any huge differences in any of the loads I have loaded and shot. I have shot them out of my BFR and my nephews S&W 500 and again, we have not noticed any great differences in accuracy, cleaning etc. Like kdub says, with LR primers (not magnum) you should be OK. Greg

Thanks guys. I'll get started.

Bryan