Just picked up two cases of this Remington (Peters) 20 ga shotgun ammo, got it almost for free (garage sale kinda thing). The two cases were still sealed until I opened one up. From the boxes, it looks pretty old. Can any of you knowledgeable ammo folks put an approx manufacture date on it, based on the box markings? Think it is still safe to shoot? The only thing I shoot with my 20 ga is trap and skeet once in a very great while - for fun, not competitively, I kinda suck at it - would trying this for trap or skeet be a waste, since it is buckshot?