hey guys I have been reading a lot about this.and I have posted on other sites but no answer.so I came back to the first sight that I have joined since my friend/coach pass away. my rifel is a rem 700 sps so yea its a factory chamber.the brass started out new.the first time loaded was with a Lee neck die to make the neck straight.they now have 4 loadings on them.the brass has yet given me any kind of trouble yet.it still chambers nice with no force.my quesion I guess is this.will I have to get a collet body die that I have been reading about?or should I wait and try my full length die to see if it works when its time to full lenght the case.and with 4 loadings already in the pictuer should I go ahead and full length? and to add if I may I all so have a 300 ackley imp.and the only die that I have for this case is a full length die.and I have yet had any trouble chambering this case. all so isn't the head space measured off the belt?remember reading this in one of PO Ackley's books.so guys if one could shed some light on this it would mean a lot to me. just wanted to add one more thing.guys ya'll have been a great group of guys to me and that means a lot to me.the other site started out nice but has been a BUTT for the past month.so I am thinking about dropping the site.just hate to since I like to read a lot on reloading.and with my coach gone to the reading capital of the world all I have is the enter net.I thank ya'll a lot for the suport that is given and the info ya'll are willing to share.thanks again,John