Help with sizing

It’s coming out of the gun 1.212.
Best I can tell, I get a stiff bolt closure about 1.218.
If I bumped it .003 out of the current length, it would be 1.209
Wouldn’t I be better off keeping it around the 1.215/6 mark?
I am with Koda here. Something's not adding up.

If the brass is coming out of the gun after 3 firings at 1.212, the 1.218 number kind of doesn't matter. Kind of hard to diagnose over the internet without seeing the brass, velocity data, etc.

Are you sure on your numbers being accurate? Is there any primer dimpling that could affect the readings?

Are you sure the 1.218 number and getting stiff bolt close isn't a case of the brass not being sized enough and growing to 1.215/6 and now your bullets are contacting the rifling?

If it was my gun and loads and the fired brass is coming out at 1.212 I am going to adjust my sizing die until my brass reads 1.210 and if I get 1.209 I am not going to worry about it. Don't go crazy and get them down to 1.206 or anything like that. But 1.210/209 is where I would want to be. But that's just me.
 
Whats interesting is saami spec for minimum chamber is 1.220" so if hes getting a stiff bolt at 1.218" he might have a short chamber but my guess is theres something inconsistent in his process or measuring.
 
I took this sized brass this morning and put it in the gun. It has slight drag during bolt closure. The 1.218 came from my notes of past loadings, so I may need to do away with that number.
If this 1.216 has slight drag, maybe I should adjust my die, no matter what, until it is giving me ~1.212 and call it good.
I may be making this harder on myself, but I don’t have anyone personally that i can reload/talk things over with. Thanks for all the help so far.
 

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You need to lube the inside of your case neck when sizing or the case can grow as the mandrel is drawn back out.
By 2 or 3 firings the brass should be fully fireformed, if your 3x fireformed brass measures 1.212 it shouldnt even chamber at all at 1.218... something is inconsistent here. In my experience, if your not annealing after every firing your shoulder bumping/sizing will never be very consistent.
My experience is the opposite, I've never lubed the inside of a neck in my life, have never been able to get an expander ball to pull a shoulder back out, and have gotten very repeatable results without annealing.

Whats interesting is saami spec for minimum chamber is 1.220" so if hes getting a stiff bolt at 1.218" he might have a short chamber but my guess is theres something inconsistent in his process or measuring.
"Headspace gauges" are actually comparators, and only good for that, comparing. They are not precise enough for determining things like the actual headspace of the chamber. The only way to determine if the chamber is short is to gauge it.

So if I’m understanding it right, I just need to keep doing what I’m doing unless the brass starts coming out of the die at more than 1.215/6…that’s about where I believe I need to be for my chamber. If the die continues to stretch it the next sizing or two, beyond the current 1.215/6, I’ll start turning the die in 1/8-1/4 more at a time until it gets the shoulder back to where I want it.
That's what I would do. I can almost guarantee the die won't "stretch" it, I've measured hundreds of sized cases with and without an expander ball pulled through and never seen a shoulder move a measurable amount. Maybe on older less sharp shoulder angles like a 270 or 06, but I still doubt it. If it gets to a point where you can't size it back enough, it's not uncommon to surface grind a little bit off a shellholder or the bottom of a cheap FL die to achieve the amount of setback needed.
 
My experience is the opposite, I've never lubed the inside of a neck in my life, have never been able to get an expander ball to pull a shoulder back out, and have gotten very repeatable results without annealing.


"Headspace gauges" are actually comparators, and only good for that, comparing. They are not precise enough for determining things like the actual headspace of the chamber. The only way to determine if the chamber is short is to gauge it.


That's what I would do. I can almost guarantee the die won't "stretch" it, I've measured hundreds of sized cases with and without an expander ball pulled through and never seen a shoulder move a measurable amount. Maybe on older less sharp shoulder angles like a 270 or 06, but I still doubt it. If it gets to a point where you can't size it back enough, it's not uncommon to surface grind a little bit off a shellholder or the bottom of a cheap FL die to achieve the amount of setback needed.
I also doubt the expander is “pulling” the shoulder longer. Most expander balls are smooth enough to avoid doing this. Again, your die is just sizing the diameter of the case body back down (acting as a body die) and that is moving material upward, elongating the overall length of the brass, shoulder included.
 
Set your sizing die to bump your shoulder back .002 from where it starts to get harder to close bolt. When you set it up take the expander ball out until you have it set. Also don't keep using the same piece of brass to set shoulder bump.
 
Set your sizing die to bump your shoulder back .002 from where it starts to get harder to close bolt. When you set it up take the expander ball out until you have it set. Also don't keep using the same piece of brass to set shoulder bump.
Thanks.
I start getting a harder bolt closure at about 1.216.
I will shoot for 1.212-1.213.
 
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