What's wrong with this photo? Do you see it? This 357 Magnum cartridge is a reload using Remington 5-½ primers. The 5-½ is a small pistol primer, but so is the Remington 1-½. I have read that the 5-½ is a magnum primer while the 1-½ is not. So what's the difference? I have also read that Remington's 5-½ has a thicker metal case than the 1-½. That would explain why I couldn't get this cartridge to fire after at least five tries, even though my S&W model 327 TRR8 has an extra long firing pin from Cylinder & Slide.
To be fair, my S&W has also had a trigger job that brings my trigger pull down close to 1 lb. To do this, my gunsmith replaced the hammer spring. I suspect that spring is a lighter one, which means the hammer strikes the firing pin with a little less energy. Experts reading this can verify if that is true or not for trigger jobs.
So why am I using Remington 5-½ primers? Because at the time, that was all I could get. It was that or nothing, so I took it. Now I am paying for that with multiple light strikes from these loads. But that's OK because I'm just using these for target practice. My loads that I am saving for serious shooting—IYKWIM—are using Federal #100 primers (and Hornady FP/XTP bullets). And I have NEVER had a light strike from my Federal primers. I have stopped using CCI #500 for that very reason.
So, my question to all who are reading this, is: Do most magnum primers have thicker cases? Or is this just a Remington thing? What is the difference between a magnum primer and a non-magnum primer anyway? Why would I ever want to use a magnum primer?

Confession: I once used magnum primers for 10mm loads. They were very noticeably sharper and louder than they should have been, though the cases didn't show signs of overpressure. My guess is that they have a larger ignition load: more spark with more force.

I inherited a bunch of Remington 1-1/2 primers. They are intended for low pressure, low performance pistol ammunition I have been using them in loading low velocity .32 S&W-Long ammunition. I am getting a lot of primer failures, where a big crack opens in the face of the primer, centered on the firing pin indent. This is not good, in that it releases a lot of gas in directions I do not want it to go, and the flame may damage the firing pin. Imagine how much worse it could be if I used such primers in high performance, high pressure loadings such as the .357.

Usually, a manufacturer's lower pressure primers have thinner cups and less explosive. I believe the performance I am getting from the above Remington primers is simply defective, they should be able to handle .32 S&W-L, but are not.