Many firearms manufacturers recommend only factory produced (read that liability insured) ammo made to SAAMI standard pressures and do not recommend handloads for use in their firearms. This is more of a liability concern than anything else. The manufacturer has no control over home brewed ammunition.
Excellent load data can be found from powder and other component manufacturers. Obtain one or two published loading manuals or visit the websites of various component manufacturers for their listed data.
I'm only guessing here but, I would also recommend to you to get a reference on Reloading ammunition in general and studying it carefully before plunging into reloading your own ammo.
It's perfectly fine to stick with factory ammo for now while you are learning the ins and outs of reloading. Feel free to post any questions you might have to the forum as I'm sure they will be answered to your satisfaction.
Assume your talking about your 5 shot 45 colt? There's plenty of 5 shot loads online.... check the "sixgunner" FAQ, might be some there. But still start low and work up. P&R uses a slightly smaller cylinder (Reeder too I believe) for their 5 shots than some other smiths. Be safe.
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