I recently starting reloading for my 223. Brass is PMC factory ammo that has been once fired in my AR. Dies are Hornady two die set. Press is LNL AP, but for sizing I use it like a single stage, only the resizing/decaping die is in it.
I have an RCBS Precision Mic, that I used to measure several once fired cases. Following the instructions, set up my die to bump the shoulder back .001-.002" from the fired case measurement. To achieve this the resizing die is screwed in about 1/4 turn more than where it just touches the shell plate when the ram is raised. Per Hornady, this is perfectly normal in order to do what I'm trying to do. The decapping pin is per spec, 3/16" below bottom of die.
My issue is if I measure several cases with the PM before and after resizing, the headspace seems to be quite a bit longer after resizing, additional .002 to .003", IIRC. I read somewhere if the plug on the decaping pin was too long into the case, it would tend to lengthen the case as it was pulled out. I made sure it was set per Hornady's spec, so I dont think that's the cause.
Could different consistencies in brass composition cause this?
I have an RCBS Precision Mic, that I used to measure several once fired cases. Following the instructions, set up my die to bump the shoulder back .001-.002" from the fired case measurement. To achieve this the resizing die is screwed in about 1/4 turn more than where it just touches the shell plate when the ram is raised. Per Hornady, this is perfectly normal in order to do what I'm trying to do. The decapping pin is per spec, 3/16" below bottom of die.
My issue is if I measure several cases with the PM before and after resizing, the headspace seems to be quite a bit longer after resizing, additional .002 to .003", IIRC. I read somewhere if the plug on the decaping pin was too long into the case, it would tend to lengthen the case as it was pulled out. I made sure it was set per Hornady's spec, so I dont think that's the cause.
Could different consistencies in brass composition cause this?