Welcome to TFL.
I load a lot of 38 Special; and have for over three decades.
I have many different case brands for my 38. Do you separate case brands when reloading
Well, I do. But only because I have so darn much of it. I possess - easily - 5000 pieces of 38 Special brass. Most likely, more like 6000+ pieces. Most of what I have is Winchester (from factory "White Box" ammo I personally shot), Starline (which I bought new), and GECO (which I have the most of - once fired by a friend who shoots a ton, but doesn't load). Then I have a whole bunch of "mixed" ( R-P, federal, etc.). Right now, I only load the GECO and the rest just sits. But that's my thing, and doesn't really answer what you want to know - sorry. If I had only a few hundred pieces of 38 Special brass and it was mixed headstamp, I would just load them sans headstamp discrimination. 38 Special, when loaded per reliable data and with quality components, won't care what headstamp brass is holding the components together and in alignment (the
real job of the brass).
Some are brass colored and silver colored, I am thinking as long as they are sized correctly it shouldn't matter.
Correct. It's not really going to matter. The "brass colored" is just bare brass; and the "silver colored" ones are nickel plated, btw. It's actually fodder for a lot of discussion, but regarding your post, there's no real difference between brass or nickel cases.
I have used x-treme copper coated bullets and they seem to do well in my 686.
X-treme makes a good product(s). I use a lot of X-treme bullets. And they are particularly well suited for 38 Special because as long as you stick with reliable published data, a plated bullet should hold up just fine; without need to step up to jacketed.
I am about to embark into loading for my .45 M&P, has anyone used the x-treme copper plated bullets in your auto and have you had any problems?
Same as above. And for the same reason. 45 ACP is also a low pressure round. And plated bullets fair equally well. I only use jacketed bullets for 45 ACP for my very hottest (self-defense level) ammo.
I have powder left over from (10 years ago), it has been sealed and doesn't appear to have gotten damp/wet. Is it still safe and if not how do I get rid of it?
Smell it. If it's still "fragrant" (for lack of a better description) and not acrid smelling, it should be fine. Five years ago, I discovered powder I left at my father's house from 1987 (that's 25 years) and it shot just fine. Granted, it was stored in near ideal conditions. Point is, I doubt you'll need to get rid of it. If you did, by odd chance, the common school of thought is to use it for fertilizer. I suppose that's an okay thing to do, but I wouldn't fertilize anything that bears fruit you intend to eat. Smokeless propellant likely has stuff you don't want to enter the human food chain.
where do you buy your supplies from (on-line or locally or both)?
Both. Usually locally. But with big purchases, I go on line. On line usually means a hazmat fee of $20 or so. But that fee doesn't increase with the size of your order; thus, it's not big of a deal if your purchasing 8 pounds or more.
Enjoy your return to loading. Be safe.
