I did 200 of them last night and decided to try 5 each way just for comparison... The shoulder does look to be a little bit more formed on the twice struck brass than the single...

I haven't had any feed issues with them and really the only downside I could see would be that the brass work-hardens faster. But after they've been fired they only get run through the die once, and I'm looking to start annealing them in the future...

Oh well, I guess I'll keep on trucking the way I have been unless anyone has a very compelling argument for why I shouldnt...

Thanks for your input.