Magnum small pistol primers help.

[gunslinger15]

I just ran out of small pistol primers so I am about to break open a case of magnum small pistol. I am currently loading 9mm and my load is a 115gr lrn with 4.6gr w231 and a 1.1 OAL. Thats about mid range for this loading min is 4.3 max is 4.8. So my question is how much difference if any will the magnum primers cause on my pressure? Can I just keep loading as usual or am I going to need stop and work a load up?

Thanks
Gunslinger

 

[Starter52]

Keep loading as usual.

 

[Walkalong]

For a midrange load you can load the same, but will likely get a small velocity increase. You could always back off .1 Gr if you want and see if the velocity matches.

 

[Steve C]

Most magnum primers are only a little warmer and won't bring pressures up much BUT if you have Winchester Small Pistol Magnum you should drop to the start level of 4.3gr as they are probably the hottest magnum primer made. Some manuals, specifically the Accurate, says to only use start loads with WSPM primers and consider that the max load.

Regardless, it is SOP in reloading to reduce charges to start level (-10% of max.) and work back up whenever one changes components.