Looking for Bingham PPS-50 Info in NFA / Semi Forum Posted 17 March hkg3k, thank you for your response. The gun I purchased is an RR. I plan on checking out which parts appear stock when I get it in my possession and I will buy what spares I can find. I have a mill, lathe and Tig welder so even if the parts I find are close but not exact I can make it work. I did see the black dog mags already and plan on getting a few. Do they feed reliably for you? I bought this gun because I was looking for a dedicated 22 MG and for the price I couldn't pass it up. Paid about a quarter of what a Norrell 10/22 would have cost.