Burch, welcome to reloading!
What is the OAL of your rounds? Are you "in the ballpark"? I load 230gr LRN's at an OAL of 1.27" with no problems.
You might consider purchasing a case gauge so you can drop the rounds in it to see if they drop in readily/easliy. (The barrel of your P345 will work but the case gauge is very handy.)
And what about the ramp on your Ruger? Is it polished adequately?
When I am setting up for loads (new), I usually load 10 to 12 rounds or 2 mags full of each charge. I mark the primers with a different color Sharpie and keep track of which work, etc. I know what "having the itch" feels like but 50 is a lot to run through if they aren't working. The patience it takes is trying. Or, you can become proficient at using a kinetic bullet puller like I did! :redface:
I check each round I build because I don't want failures at the range. Sometimes there will be small pieces of lead that hang around the top of the casing. I clean them off and wipe the round off with a rag. I don't have an opinion about the Scotch Brite pad.