Several years back a brick of Thunderbolt ammo was bought (I don't recall who actually paid for it). It wouldn't feed in any of our 22's. I think most of it was returned (and the store actually took it). This was when the 500rd bricks were actually 10 50rd boxes. We had to fight to get through that opened box. Ever since I won't buy Thunderbolt ammo, and yes, I realize that its very likely that it has beed redesigned since.