I have a pair of RCBS Loading blocks that I bought off here a while ago. I wanted them to reload .308 & .243 brass but they do not fit in all the holes, only some f them. So some brass go in as expected and about 1/3 of them get stuck halfway in & sit at a slight angle. I think these are for smaller sized brass. I have got my self a pair of the deep blocks from Spud, so these are no longer needed.