Mostly good for 1 st generation Remington plastic hulls the see thru transparent green ones . The ones with the composite base wads. So were talking mid 60's to early 70's in their hunting loads hulls.
IIRC the old All American RP target hulls with the high base wad used 209 sized primers. Mb


" Cheapest velocity in the world comes from a long barrel and I sure do like them. MB "