The cylinder would have been what would have went with an overload.
However I have a rule on any ammo, if it don't come out of a factory box, I break it down. If it is a box or part of a box and I was not the one to buy it from the store, I look it over very carefully and make 110% sure it is factory ammo. If I can't tell, I break it down. I shoot only reloads that I have made.
Nephew learned a lesson along this lines about a year and a half ago, bought some reloaded 308 at a gun show and not from and establish comerial reloader. (I consider this factory ammo) 30th or so of 50 took a Ruger M77 apart. I disected every left over round, looks like 231 in varied amounts per round mixed in with what looks like 748.