I've got a friend who has come on hard times and is trying to sell off some small pistol magnum primers. I've got them listed here in the classified so that part of this thread is a shameless plug for the ad.
That said, I'm thinking about buying them and substituting them for a load I've worked up using regular non-magnum primers. I realize I'll need to start over working up that load if I do that. I'm trying to figure out the actual "hotness" difference between them and regular small pistol primers. I've seen posted chronograph results between the two using the same amounts of powder. About all I can get from that is it seems that, when using faster burning powders, the chronograph results show an almost negligible difference in fps, usually in the 10 to 15 fps increase. I'd be using VV N320 in 9MM pushing a 124 gr. bullet and I know that powder is a relatively fast burning powder. Currently for that bullet I use 4.1 grains and get an average fps of about 1038 fps. Using regular small pistol primers I've gone as high as using 4.3 grains with no over pressure signs. If I use the magnum primers, I'd start at 3.8, maybe 3.9 grains of N320.
Anybody on this board have any experience switching between small pistol primers and small pistol magnum primers? If so I'd sure appreciate your experience with doing that.
That said, I'm thinking about buying them and substituting them for a load I've worked up using regular non-magnum primers. I realize I'll need to start over working up that load if I do that. I'm trying to figure out the actual "hotness" difference between them and regular small pistol primers. I've seen posted chronograph results between the two using the same amounts of powder. About all I can get from that is it seems that, when using faster burning powders, the chronograph results show an almost negligible difference in fps, usually in the 10 to 15 fps increase. I'd be using VV N320 in 9MM pushing a 124 gr. bullet and I know that powder is a relatively fast burning powder. Currently for that bullet I use 4.1 grains and get an average fps of about 1038 fps. Using regular small pistol primers I've gone as high as using 4.3 grains with no over pressure signs. If I use the magnum primers, I'd start at 3.8, maybe 3.9 grains of N320.
Anybody on this board have any experience switching between small pistol primers and small pistol magnum primers? If so I'd sure appreciate your experience with doing that.
