I haven't heard that one, but there are a ton of rumors going around.
I don't buy powder by the barrel, just by the can. I haven't had any trouble finding the ones I use, but I have noticed that certain bullets are becoming backstocked. I don't really shoot high volume any more. When I do I shoot .22 or .17. The only pistols I own are a Walther P22 and a Ruger Blackhawk 45 Colt. I load all my 45 colt and .22 is still really cheap.