Remington primers

[Froogal]

I've never used any Remington primers, but I am a bit confused. What is the difference between 1 1/2 small pistol and 5 1/2 small pistol? I assume one of those is for standard loads and the other for magnum loads, but which is which?

[Abilene]

A little Googling showed:

Remington's recommended use of the 1½ primer implies a difference in cup thickness or cup strength such that the 1½ won't handle the same amount of pressure as the 5½, or other brands of small pistol primers that don't have warnings about using them in particular cartridges.

and, from a Smith and Wesson forum:

rem 1&1/2 vs rem 5&1/2, being disatisfied with all forum answers about a year ago, i call rem factory, and got this answer. NO change in power, just cup thickness. they use 5&1/2 for factory loaded 357 sig and 40 S&W to prevent flow-back into the firing pin opening. i use it for everything including 38spl & 380 with no problems. they said it is NOT a magnum primer.

That's as far as I looked.  So, if I was using them in guns with lightened springs, I might not want the thicker cup 5 1/2.

[Froogal]

A little Googling showed:

Remington's recommended use of the 1½ primer implies a difference in cup thickness or cup strength such that the 1½ won't handle the same amount of pressure as the 5½, or other brands of small pistol primers that don't have warnings about using them in particular cartridges.

and, from a Smith and Wesson forum:

rem 1&1/2 vs rem 5&1/2, being disatisfied with all forum answers about a year ago, i call rem factory, and got this answer. NO change in power, just cup thickness. they use 5&1/2 for factory loaded 357 sig and 40 S&W to prevent flow-back into the firing pin opening. i use it for everything including 38spl & 380 with no problems. they said it is NOT a magnum primer.

That's as far as I looked.  So, if I was using them in guns with lightened springs, I might not want the thicker cup 5 1/2.

Yes. I eventually used the proper search terms and came up with those results. Looks like for most purposes, the 5 1/2 is what I want.