Bought some once fired brass from a buddy who says he fired from same rifle. There seem to be some variations in headspace in fired brass from my friends rifle. Not a lot but enough that I have to keep screwing in or out my FL bushing die.
I use am RCBS precision mic and try to get the brass at zero because that is what my headspace is after doing the Eric Cortina method to find headspace removing the firing pin and ejector from the bolt and seeing the bolt drop loosely then putting piece of tape on the head to see if bolt does not close. This brass, I measure on a comparator and the mic. The most perfect headspace in my rifle is zero on the mic which means its sammi spec chamber.
The issue I find is that not every once fired formed brass is the same headspace. Some are taller shoulder and other are shorter shoulder. Therefore I cannot always use the same settings on my FL bushing die. I have 2 points marked on my press to where its max shoulder bump down which is greater space in chamber and the other is the most minimum which means not even touching the shoulder. Basically screwing in and out the die.
First without measuring I run the case in the die using the point where its the most minimum shoulder bump then I measure. If its +.003. I just nudge the die, screwed into or more shoulder bump then I run the case again. Then I measure again and hopefully its at zero or -.001. Basically every time I run the case I am moving it closer to zero or -.001. No greater than that, I move the case to the pile of -.002 and another pile of -.003.
I hope this makes sense to someone. I know there are Redding comp shellholders or the widden clicks or the rings with marks. I am even hopping to get the new area 419 zero FL micrometer die. But even with all these reloading gear if the brass has variations you still need to adjust every time. And measure every time.
AM I over doing this thing. I haven't tried virgin brass yet try to measure the first fired brass to see if there is variations there also, but I have heard there is. If this is the case I will have to measure every time to get my brass to perfect headspace there is no running way from this if I want perfect headspace cases. FYI I also anneal before re-sizing then I plan to neck turn after 2nd firings.
Last question...Are there differences in headspace when you crank hard or how many times you crank on the reloading press ram? Does it increase the shoulder bump the harder you crank on it???
I use am RCBS precision mic and try to get the brass at zero because that is what my headspace is after doing the Eric Cortina method to find headspace removing the firing pin and ejector from the bolt and seeing the bolt drop loosely then putting piece of tape on the head to see if bolt does not close. This brass, I measure on a comparator and the mic. The most perfect headspace in my rifle is zero on the mic which means its sammi spec chamber.
The issue I find is that not every once fired formed brass is the same headspace. Some are taller shoulder and other are shorter shoulder. Therefore I cannot always use the same settings on my FL bushing die. I have 2 points marked on my press to where its max shoulder bump down which is greater space in chamber and the other is the most minimum which means not even touching the shoulder. Basically screwing in and out the die.
First without measuring I run the case in the die using the point where its the most minimum shoulder bump then I measure. If its +.003. I just nudge the die, screwed into or more shoulder bump then I run the case again. Then I measure again and hopefully its at zero or -.001. Basically every time I run the case I am moving it closer to zero or -.001. No greater than that, I move the case to the pile of -.002 and another pile of -.003.
I hope this makes sense to someone. I know there are Redding comp shellholders or the widden clicks or the rings with marks. I am even hopping to get the new area 419 zero FL micrometer die. But even with all these reloading gear if the brass has variations you still need to adjust every time. And measure every time.
AM I over doing this thing. I haven't tried virgin brass yet try to measure the first fired brass to see if there is variations there also, but I have heard there is. If this is the case I will have to measure every time to get my brass to perfect headspace there is no running way from this if I want perfect headspace cases. FYI I also anneal before re-sizing then I plan to neck turn after 2nd firings.
Last question...Are there differences in headspace when you crank hard or how many times you crank on the reloading press ram? Does it increase the shoulder bump the harder you crank on it???
