I have a bottle of those pellets that are maybe 5 years old. I'm guessing your talking about the round ones as opposed to the square ones. They shot OK with one or two pellets but often when using 3 the third one came out more like a flare rather than burning properly and adding to the projectiles velocity. I've not noticed any deteriation of the pellets so far but I also have them in a sealed box and live in a dry climate (NM). I just use them as a bore fouling powder before loading my hunting load. I never did find a good load that I trusted for hunting consistency. I would ask him to let you try out a bottle first before deciding if you want the whole case, or just walk away from the deal. That's my 2 cents.