full length or neck sizing on a short fat case?

Opinions are like elbows(?). Almost everybody has one. Try neck sizing and see if it works in your rifle. Short Mags have fairly sharp shoulders so case stretch should be minimal during firing. Neck size and see if the case chambers. If it has excessive resistance, then you know it didn't work in your rifle. If it doesn't, neck size only. If is has resistance, try partial full length resizing. Before i would use non-full length resized ammo for hunting, I would insure that every round chambers easily. Experiment and see what works for you. Reloading isn't an exact science.
 
If it's not an improved cartridge, and you expect more than ~8 reload cycles, your chance of success with NSing only is low.
That is, by 'chance'.
- Low shoulder angles and high body taper runs you out of head spacing with relatively few firings, as brass grips chamber front toward back, with excess stretching due to angles. From then you need to bump shoulders at least, -every time, going forward.
- If your chamber is sloppy SAAMI, then near web brass will expand to yielding, and brass forever wants to go where it's been.
With relatively few firings you can end up with an interference fit at the breach & popping extraction from that.
From then you need body sizing, -every time, going forward.
Without mitigating efforts, these are near certainties. Won't take much for 'trying' to see this.

It doesn't mean these issues can't be headed off to begin with, or that FL sizing is actually required, or better.
It just validates, as millions have, that doing things by chance will likely take you to right where they went.
If you only get 5 or 6 firings from brass before pockets loosen, then nothing is going to help other than to run lower pressure loads.
No sizing type will help.
If you WANT more brass life, then you will need to adjust things right from the git-go, just for that.
 
That math doesn't work for some of us here.
Our brass is fire formed to stable before we have stable results.
2-3 fire formings of 300 cases, at a case life of 5, leaves only 2 long range hunting shots each (600 total remaining) before we would have to replace the whole batch & start over.. That would also be the time to replace the barrel.
Some of us would see this as a problem, needing solution.

Going with a viable plan to get 15, 30, or 50+ reloads from cases, and reducing the case batch to ~50 pieces per barrel, changes all the numbers for the better. That's my solution.
My endeavor is killing groundhogs to 650yds. That's not a lot of field shooting,, around ~100/yr.
Maybe I enjoy my shooting range too much...
I've never heard of any more than one fire forming shot for any case. What's the purpose of this and do you have custom barrels? Since so many people seem to get great accuracy from full length sizing it just doesn't seem right that you need more than one fire forming shot.
 
I've never heard of any more than one fire forming shot for any case. What's the purpose of this and do you have custom barrels? Since so many people seem to get great accuracy from full length sizing it just doesn't seem right that you need more than one fire forming shot.
Your cases HAVE NEVER fully fire formed in one shot.
Most people FL sizing never reach a stable fire formed condition.
Their brass changes a little with every sizing.

For those wanting stable and max brass life, fastest fire forming occurs after a deep body dip anneal.
Otherwise cases are not stable in capacity until 3 fire formings are completed without sizing.
That's where I can minimally size and begin powder development from it.
 
Your cases HAVE NEVER fully fire formed in one shot.
Most people FL sizing never reach a stable fire formed condition.
Their brass changes a little with every sizing.

For those wanting stable and max brass life, fastest fire forming occurs after a deep body dip anneal.
Otherwise cases are not stable in capacity until 3 fire formings are completed without sizing.
That's where I can minimally size and begin powder development from it.
Well they could but it's life would be 1-2x maybe lol

People also have dies/chambers brass that are not spec'd to work ideally with each other as a system. Its why sticking with quality tough brass manf helps as it all starts with the virgin case (obviously improvements accounted for). Base everything off that.

There is a good reason die makers only want cases that have been 3x fired, neck size only to spec from.
 
Your cases HAVE NEVER fully fire formed in one shot.
Most people FL sizing never reach a stable fire formed condition.
Their brass changes a little with every sizing.

For those wanting stable and max brass life, fastest fire forming occurs after a deep body dip anneal.
Otherwise cases are not stable in capacity until 3 fire formings are completed without sizing.
That's where I can minimally size and begin powder development from it.
OK... I can find where people on Benchrest.com and Accurateshooter.com mention fireforming 3 times in order to get brass perfectly fitted to a chamber so it can be sent off to have custom dies made to perfectly mimic a chamber but couldn't find where these forums where the guys (and gals) that deal with the minutia needed for competition benchrest accuracy mention it. The only mentions I see there are fireforming one time and then neck sizing after that.

Can you provide something authoritative mentioning the need for 3 fireforming shots for accuracy? I can't find it and since my primary focus over the last 10-15 years has been looking for the holy grail of the 1/4-1/2 group out of hunting rifles I may have missed something.

I used to read a fair amount on Benchrest.com and unless this is something new I never even heard of competition shooters doing anything more than 1 fireforming shot to prep brass for competition.
 
Well they could but it's life would be 1-2x maybe lol
Can you provide something authoritative mentioning the need for 3 fireforming shots for accuracy?
I do 2X max, esp. on wildcats. I, too, am interested.
deer-eats-popcorn_64.gif

Frankly, I cannot believe we are still discussing this. @ZAK13, did you get the answer you were looking for?
 
PARTIAL FL SIZE is the CORRECT term. Bumping shoulders less than what the die is capable of doing is described above.
If you are screwing the die in until contact with the shell holder and locking it in place like that is NOT FL SIZING…

Cheers.
That's what the instructions in my reloading die box says it is. What would you call it?
 
Can you provide something authoritative mentioning the need for 3 fireforming shots for accuracy?
I never said nor implied that you have to fully fire form for accuracy.
I suggest that full fire forming can take brass to a stable consistent form, which I prefer as a baseline for my cases -because I do not FL size.

You can measure to see this yourself if you like. It's a measure of H20 capacities.
A good indicator of individual case character also, as it shows the witches in your batch. The cases that just aren't springing back the same as the others.
Then I have to remind that if your FL sizing cases, your capacities are not matching anyway. You might as well forget the effort, as your demigods have.

There is a reason FL sized cases can shoot well, despite so many flaws.
It's due to peak pressure flattening, from energy consumed to expand cases more. Many see this as new brass producing lower MV/pressure than fire formed brass. Similar pressure peak flattening occurs with the 'competitive' 6PPC load, as it's so high as to be deep into diminished returns. Diminished returns equals diminished variance of returns, so point blank competitors can throw charges instead of measuring them, and shoot just fine.
Basically, both are forgiving conditions to powder.

So why would I choose to not FL size?
--Case Life--
I want my cases to last ~forever,, while measuring and shooting exactly the same over the long run.
I can do this, with all the accuracy ANYONE could expect from my hunting guns, with planning that includes minimal sizing.
Can't do it with FL sizing, as there is too much changing with every cycle, and it can't be undone..
 

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