Everybody is going to have there own take and level of safety they are comfortable with. Personally I would take them apart myself unless you know what the load is. I would still take a couple apart to verify powder charge. Just did that with a whack of 7x57 reloads I bought. Speer stickers on the boxes listed the charge, bullet weight, powder, primer, and velocity. Loads were listed 15-20% over max charges using today's modern day reloading data. There were a few spent casings in the box also. The primers were flattened badly and the firing pin indent was cupped. I took several apart to see what was what. Powder charges were all over the place with the majority on the excessive side. Proceeded to disassemble somewhere around 250 rounds. Was more interested in the brass, but saved most of the bullets. Powder & primers turned out to be OK as well. Unfortunately the seller could not remember what rifle his dad had used.
Main thing is to be careful. If you feel comfortable then go for it if not then other avenues may need to be explored.