Long story short. A friend of mine purchased a few guns from a widow and she threw in a complete RCBS Rockchucker kit free, new in box, except the press which was gently used. He doesn't reload so freebie for me. In the mix was a set of 4 dies. Im used to the 2 or 3 die rifle sets so I'm scratching my head. Some are self explanatory but I'm slightly confused. One reads on top "38-357 Carbo F.L." I'm thinking it's a carbide full length die. Easy right? 3 are marked RCBS but the oddball reads " 38 spl crimp seater" has a C with a H in it. I'm thinking it's a add on. Flame away but at least shed some light on the CH die. I'm not a newbie to reloading rifle but I'm still learning handgun. And these dies are 6 years older than me.