SP primers vs SPM primers

[Fontana101]

Hey i'm sure this question has been asked before but I have grown tired of searching the forums, also cant seem to find a straight answer when googling.

I have been handloading for awhile (9mm and 5.56) and want to start loading for my S&W 686 .357

I picked up a box of 1000 CCI 550 small pistol primers magnum before I looked in to it assuming via common sense that I would need magnum primers for a magnum cartridge. When I go on to Hodgdon data center it lists at the top to use magnum primers. In the Lee book it says small pistol primer on top of first page of .357 section. I'v read on other forums how you should use magnum primers with certain ball type powders, but don't have to. Then with other powders you should use regular SP primers only.

I would like to use the SPM primers since I cant return them.

Does anybody have any input on this?

I got Titegroupe and HS-6 powder. Figure i'm going to use the Titegroupe for .357 and HS-6 for 38 special and 9mm loads following the recommend uses of these powders from the Hodgedon website.

 

[B]

With proper load development there is nothing wrong with switching components. HS-6 would probably benefit from a mag primer. Titegroup will burn fine with whatever you use.

 

[Spawn-Inc]

you can use them for any small pistol primer calibre, just work up your loads with the new primers if you want to be ultra safe about things. unless you at or over max loads with a non magnum primer i would swap them without changing the load. for light or medium loads it's very unlikely anything would change and cause high pressure issues.

i just got a 223 gun and lebaron only had small rifle magnum primers so i will just use those for load development, when i get some regular small rifle primers i will keep the same load data and or just stick with magnum primers.