Magnum Small Pistol Primers??

[Point&Shoot]

Just a quick question..
I usually use CCI small pistol primers (500) but today I grabbed a box of the CCI Magnum small pistol primers (550). I would appreciate it if someone could tell me what special considerations I should take into account? Right now I'm set up on the Dillon 550b for 9mm. I'm currently loading 115 grain RN Xtreme, Berry's and FMP bullets over 4.7 grains of W231. What effect if any will the magnum primers have on this load? Certainly not enough that I should reduce my powder drop I wouldn't think but better to make sure than do anything stupid. Thanks

 

[BrianWilson]

I would suggest going back and getting SPP. If they were the last primers on earth I might consider starting low and working up with them, but they aren't.
High pressure round, near max load of a fast powder might not be a good place to start a science experiment.
Good excuse to buy a 357, if you don't already have one.

 

[headednorth]

Could call CCI if you are intent on using them up. I'd either get reg primers and sell/trade the mags or call the manufacturer and get data from them.

 

[wmccurdy53]

I have used magnum primers when I couldn't get non-magnum.
I built 10 rounds to test over crono using the same powder drop.
The test rounds cronoed 60-75 feet per second faster than non magnum.
I now use them interchangeably.

 

[EddieCoyle]

Go to 4.4 or 4.5 gr on your powder charge and you're good to go.

I always use magnum primers with 231 anyway because they deliver more consistent velocity than standard primers with that powder. Ken Waters recommended this, and he forgot more about handloading than most of us combined will ever know.

 

[Point&Shoot]

I like wmccurdy's and Eddie's answer the best. I'll reduce my powder drop from 4.6 W231 to 4.3 and see how it goes.
It's my fault but I recently bought a box of small pistol and a box of large pistol from a big box store and when I got home the clerk had given me large rifle instead of large pistol. My fault for not checking but Geez...
Thank you gentlemen