I am new to reloading but have found everything I need to reload .223. Of course my main priority is to be safe. The powder I have is winchester 748 and I have read that it can be temperature sensitive. It is very cold right now where I am, and I will probably shoot a lot in summer when it is very hot. Temp difference of upwards of 90 degrees. Other than loading and testing closer to when I will be shooting, what recommendations do you have for a safe, year round plinking round? I understand that I will sacrifice some accuracy. I will be using: Mixed head stamp brass Cci 41 primers W748 powder Hornady 55gr fmjbt Also, is there a problem loading 5.56 cases to .223 specs?