what happens with excessive resizing and headspace....

[bsumoba]

Just so others will learn from my experience, this is what happens if you size your brass too much...case head separation.

The dent is from the gases escaping from the separation and had nowhere to go since it was from a bolt action gun.

Luckily, nothing was damaged, chamber still looks good and ultimately, had to scrap 80 pieces of brass that was done in this manner.

Moral of the story, do not switch from one press to another without re-checking the setup...even if it is the same exact press. If I had a go/no-go case gauge, I might have been able to prevent this upon setup.

Left brass was one that I shot as a sighter shot, but was a piece that was not part of the brass that was excessively resized. I thought I just had a piece of brass that was weak after the first one. When 3 of 5 shots did this, I stopped and knew I did something wrong. Funny thing was...I had a 1/2" group on paper, even with all this going on.

[50 Shooter]

What did you do to the brass in between shooting them? Did you anneal them? Trim back to spec? How many firings on the brass?

[JMP]

Hmmm, that's funny, I think I recently got a lecture on this forum on setting up dies where it was always good to size just based on die to shell plate and your actual chamber didn't matter. Yes, you always size to your chamber, and it is always better to under-size and check and see that it doesn't fit than to over-size and ruin your brass. (I suppose you can pull them and fire form them back out, but it probably isn't worth it seeing your brass looks fairly used).

Personally, I am a fan of tight chambers that do not require much sizing.

[LynnJr]

JMP
You got a lecture from people who don't know the difference between reloading ammo and maximising your ammo for all it can be.
They only understand loose sloppy chambers and reloads with 0.010 headspace is perfectly fine.
There brass will go into any chamber but it doesn't fit them correctly.
I am sure Bryan's chambers is very tight and full length sizing so the shellholder hits the die gives you wrecked brass as the end result.

Bryan the key to winning matches starts with perfect brass so on your way to work roll down your window and throw out your no go Gage as it has no purpose. Only bring out the go Gage when you need a new barrel.
Size your brass for each chamber so there is a very faint drag on your brass as the handle is dropped with the firing pin assembly removed. On your BAT you don't need a tool to remove or install the firing pin assembly.

[bsumoba]

JMP
You got a lecture from people who don't know the difference between reloading ammo and maximising your ammo for all it can be.
They only understand loose sloppy chambers and reloads with 0.010 headspace is perfectly fine.
There brass will go into any chamber but it doesn't fit them correctly.
I am sure Bryan's chambers is very tight and full length sizing so the shellholder hits the die gives you wrecked brass as the end result.

Bryan the key to winning matches starts with perfect brass so on your way to work roll down your window and throw out your no go Gage as it has no purpose. Only bring out the go Gage when you need a new barrel.
Size your brass for each chamber so there is a very faint drag on your brass as the handle is dropped with the firing pin assembly removed. On your BAT you don't need a tool to remove or install the firing pin assembly.

The only go/no-go gauges I have are for my ARs in .223 and .308 and thats because I have to bump the shoulders back quite a bit on those to make sure I get a reliable chambering.

For my 6.5 creedmoor, 284 Shehane and 6 Dasher, I have no gauges and do everything by taking my fired brass and measuring the headspace and then bumping back very little, as little as possible. My problem was I bought a 2nd Forster Co-Ax and for whatever reason during the changeover, my die probably changed or moved and while resizing, because the Co-Ax has so much mechanical advantage, I did not notice it camming over to the point that I sized the brass too much.

Again, lesson learned.

I do FL resize everything, but with my 6.5 creedmoor, which is what this brass is, I have to actually bump the shoulders back a little more than say my F-Class stuff because I have to be able to run the bolt quick and having brass that is a little tight on bolt close is not good when you're up against a timer.

I know how to take my firing off my BATs and I like that about the BATs that you don't need a tool. I almost bought their tool but found out how to do it without one. Never tried it on my Defiance action though. I rarely spin the barrels off my tactical rifle.

[bsumoba]

What did you do to the brass in between shooting them? Did you anneal them? Trim back to spec? How many firings on the brass?

I annealed and FL resized and trimmed them. Problem is I switched from one press to another and the other press had just enough difference (same press...a Co-Ax) that it bumped the shoulders back too much and ultimately, my whole brass was resized too much.

[ExtremeX]

Hmmm, that's funny, I think I recently got a lecture on this forum on setting up dies where it was always good to size just based on die to shell plate and your actual chamber didn't matter. Yes, you always size to your chamber, and it is always better to under-size and check and see that it doesn't fit than to over-size and ruin your brass. (I suppose you can pull them and fire form them back out, but it probably isn't worth it seeing your brass looks fairly used).

Personally, I am a fan of tight chambers that do not require much sizing.

[ExtremeX]

What did you do to the brass in between shooting them? Did you anneal them? Trim back to spec? How many firings on the brass?

None of that stuff really matters with what the OP experienced here...

You don't anneal to the base of the case, which would end up in a catastrophic case failure anyways... annealing only treats the neck shoulder area.

Bottom line is you want the minimum sizing for reliable operation... And the amount you size is based on the chamber of the rifle you are reloading for.

The more you size, you more the brass has to grow when fired, ultimately overworking the brass in less cycles.

Oversize brass = less accuracy, less brass life, and in the OPs case, case failure.

Correctly sizing to your chamber promotes brass life, safety, and just makes for better performance potential.

As an example I size my cases about .001 to .0015 smaller than my rifles chamber... If I setup my dies per the instructions (allowed the die to touch the shell holder) I can size about .006 smaller than it needs to be.

I am probably on my 10th firing on 1 set of brass and still hasn't giving any signs of case head separation... I suspect the neck or primer pockets will give out before the case head.

[LynnJr]

ExtremeX
Great post!!!

[fguffey]

The dent is from the gases escaping from the separation and had nowhere to go since it was from a bolt action gun.

There could be a whole lot more going on that you described. The dents in the case could be caused by slow powder. It is possible the hot high pressure metal cutting gas did not expand and seal your chamber. When that happens expanding gas is trapped between the case and chamber, once the pressure drops inside the chamber the gas trapped between the case and chamber is greater than the pressure inside the case. When that happens the case starts to collapse, problem, the chamber is not designed to handle the hot high pressure metal cutting gas.

F. Guffey

[eric n]

Do the threads on identical presses from the same manufacture index the same?

[fguffey]

Do the threads on identical presses from the same manufacture index the same?

I adjust the die every time I use one, I do not secure the lock ring to the die, I secure the die to the press with the lock ring. All of my presses and dies have 7/8X14 threads, most of my dies have 7/8X14 threads.

I have 5 Rock Chuckers, two of them are used on Piggy Back 11 attachments. When INDEXING? I use a feeler gage. I have a set of Redding competition shell holders for belted magnum cases, I do not use them but I have them because I paid $5.00 for the set at a gun show.

F. Guffey

[JTROKS]

Changing press even if same brand and model will result in difference with the shell holder and die setting. I learned that switching shell holder (same brand) will have an effect on sizing length. As cutters and tooling wears out the dimensions on the end product changes.

[eric n]

I didn't think they would be the same.
Roger on the shell holders, I keep an individual shell holder with each die.
Brian, I got sloppy last weekend.... Blanked a primer because I thought I could get one more firing from brass that had a donut. Live and learn, it won't happen again. Gotta learn from our mistakes.

[opos]

I just went through a "dog and pony" show with a over max headspace chamber, with resizing, etc and the outcome was as follows..

I was having slightly protruding primers....being a 7x57mm Mauser Interarms Mark X I suspected factory loads were so light (typical of factory 7mm ammo) that all was well and by stepping up the loads things might be ok (didn't help the primer issue)...in the meantime I checked the headspace...the rifle ate the no go but was dead tight when using the field..investigation showed the real headspace to be just about .001 over the no go. I'd been full length sizing (even though this is my only 7mm) because I'm sometimes lazy.

There was no indication of any incipient head separation issue..no ring..no "lip" inside the brass near the head, nice accuracy and no issues at all except a very slight primer protrusion.

I took a bunch of fired brass.."custom fit it to my chamber"..carefully neck sized with a Lee Collet die, verified the trim and loaded a "medium" load and bingo....no pushed primers...no issues at all and killer accurate...when the time comes to bump the shoulder back after some neck sizings I'll probably again custom fit the brass to the chamber and maybe bump the shoulder a thousanth or two.

Read Hatcher's notebook on headspace..especially if you are dealing with a military action bolt gun or one that is an offshoot of a military design..