Once fired brass to measure or not, headspace questions

[Barzor]

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???

 

[straightshooter1]

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???

You shouldn't have to "crank hard", but depending on the press and how much play there is in the linkage. . . yes, that can make a difference. I'd say, don't "crank hard" and be consistent. The best When sizing, allow for some dwell time (like 4 or 5 seconds) to give the brass movement time to settle in. Just pushing the brass into the die and immediately out once it hits a hard stop will produce some inconsistencies, a lot due to variances in the brass thickness and/or hardness of the brass.

 

[Barzor]

You shouldn't have to "crank hard", but depending on the press and how much play there is in the linkage. . . yes, that can make a difference. I'd say, don't "crank hard" and be consistent. The best When sizing, allow for some dwell time (like 4 or 5 seconds) to give the brass movement time to settle in. Just pushing the brass into the die and immediately out once it hits a hard stop will produce some inconsistencies, a lot due to variances in the brass thickness and/or hardness of the brass.

Your right if Im consistent same amount of force and speed does help but as you mentioned there is variations in the hardness of brass and as I mentioned I have to measure the brass everytime. When you want precision for 50 cases it takes a lot of time for every step of reloading.

 

[Rocketvapor]

Just like it takes a couple firings to fully fireform NEW brass, you will have to fire form, at least once to get consistent results.
Anneal, if you can, size, shoot, and now measure.

Make sure you lube the BODY of the brass, set die, run press to stop.
The last little bit will feel mushy, not like a brick wall. Ease case out about a 1/4" then push to stop again, hold for a couple seconds. Should feel like a hard stop this time.

 

[Doom]

Since the brass was shot in a different rifle than you intend to shoot it in I would set the shoulder back so that they are slightly less than what you would normally do for your cases shot in your rifle.