I saw a review for
Remington magnum small pistol primers (midwayusa.com) on Midway (if you click on reviews, it's the second one down) and it made me wonder.
First, I'm not using these exact primers, (I use Federal #100 aka non-magnum small pistol) but I was wondering how many people use a magnum primer for the 40 S&W cartridge? And could the non-magnum primers cause me any troubles?