Headspace with full length resizing

[Mikecr]

I see the same as Bart, and have taken to fine adjusting HS with lube.
I creep into my HS value, which is unique to each of my cartridge/chambers, with a tolerance of -0.0005+0.0000.
But I don't FL size.

As bart mentioned, cases change with every FL sizing.
So with this, I would not expect precision near mine. Not in the long run.

 

[Bart B]

I see the same as Bart, and have taken to fine adjusting HS with lube. . . .but I don't FL size.. . . . As bart mentioned, cases change with every FL sizing. . . . So with this, I would not expect precision near mine. Not in the long run.

I agree, I and others don't get the precision you do. The best we got accuracy wise with full length sized case headspace spreads of 2/1000ths inch that could be counted on all the time was no worse than about 1/4 MOA at 100, 1/3 at 300, 1/2 at 600 and 5/8 at 800 and 3/4 MOA at 1000.

 

[BountyHunter]

I see the same as Bart, and have taken to fine adjusting HS with lube.
I creep into my HS value, which is unique to each of my cartridge/chambers, with a tolerance of -0.0005+0.0000.
But I don't FL size.

As bart mentioned, cases change with every FL sizing.
So with this, I would not expect precision near mine. Not in the long run.

Maybe, but as Paul Harvey says here is the other half of the story:

IF you truly get that, it is as you have stated here it is only by holding PSI to 53,000 max for all your cartridges AND FL sizing the body with a body die. Your words here. So it is really not just NS alone as you seem to indicate.

So lets put that in some perspective as being a suitable method of reloading for LR Hunting:

That puts a 62,000 PSI 308 Winchester in the 300 savage lane and a 300 RUM equivalent to a lever action 307 winchester.

Pretty sure that is a trade off that few here are willing to make. So not sure how relavent your "method" is to a LR shooter in reality.

Plus at normal pressures cases that are really NS ONLY (no body dies) will grow also and expand to the point that they are hard to chamber and extract. Proven fact time and time again.

What you are saying does not even pass the common sense test for regular PSI loads.

Guess what cases expand every time on NS too. Plus they never start off the same dimensions to begin with. Case do not expand to one dimension on the first firing then stay there for X number of firings and SUDDENLY jump dimensions and are hard to chamber. They are changing and growing every shot. Simple physics. Again, measurements with as four place blade mikes for the body and headspacing measurement tools allow anyone to see that.

Yes I have found the redding comp shellholders are great and I have to watch my lubing.

On cartridges where I am really am trying for max accuracy, I like a custom die to minmally FL size, with no expander button and I can get extremely uniform cases and long case life. Yes you occasionally trim, but that sure beats a case hard closing or extracting in a match or hunting. I tend to like the Neil Jones dies and the Jim Carstenson FL bushing die made from a body die that is honed exactly for minimal resizing and straight decapper with expander ball.

 

[Mikecr]

BH, Pretty sure I've implied that MY MAX is typically ~55-57Kpsi.
You've countered before that these are unrealistically low pressures for performance.
Is that half the story?

I just pulled this info from my logs for current guns, and while I could certainly push each cartridge harder, my loads are inline with the pack, and as accurate as I've found for these barrels.
I'm content with them.

6.5WSSM imp, 139LAP, 28"barrel, 3050fps, ~57Kpsi QL, 47.4-IMR4350
Fitted cartridge, shoulder bumps only on 30+ reloads, Zero body sizing so far, no trimming, no annealing.

6BR, 95VLD, 26"barrel, 2975fps, ~55Kpsi QL, 31.6-IMR4895
Tight neck, shoulder bumps, no body sizing, no trimming, no annealing, (~15reloads).

6XC, 105vLD, 28"barrel, 3040FPS, ~56Kpsi QL, 40.3-H4350
Haven't shot/reloaded this much(320rnds), brass & die changes, just found a load that shoots well.
It's a safe queen..

223, 50Jayner, 24"barrel, 3630fps, ~64Kpsi QL, 27.2-H322
Cooper chamber. Latest lot of powder took me to this upper node. Bumping, some body sizing, soon to anneal, soon to trim.
This is holding without clicking extraction, but will need FL sizing(or replacement) before long. It's inherent to design anyway.


Pretty sure I've also mentioned that cartridge design & capacity are choices.
If you want performance without moving brass all over hell, you just pick the appropriate cartridge design & capacity for the bullet. If somehow the design, capacity & powder combo doesn't exist to get you there(hard to imagine), then you choose or not to accept the prices for performance despite.

YOU choose to push cartridges into needing FL sizing, I choose not to.
The FACT is, it is a choice. You can prove it to yourself or not.
I have no FL sizing dies. I do not FL size the bodies, shoulders, necks.
With Wilson bushings and Redding/JLC body dies, I partial NS, bump shoulders, and rarely(only with a 223) size the bodies.
Maybe that's semantics, but the line that indicates FL sizing IMO is the need to trim. That is, if you have to trim regularly, you are FL sizing. I don't.
If your custom FL die doesn't take you to trimming, that's great, it's not FL sizing.

Workin towards the rest of the story here..

 

[Bart B]

For those able to make sized case headspace clearance (difference between chamber headspace and case headspace) to a 1/1000th inch spread, where's your case shoulder relative to the chamber shoulder when the primer fires?

 

[kc0pph]

Where is the Beer and Peanuts, this is starting to get entertaining.

 

[Bart B]

Where is the Beer and Peanuts, this is starting to get entertaining.

They're on sale at discount prices in local sporting goods stores right next to the full length sizing dies. That's cause those dies resize cases such to shoot in normal size SAAMI spec chambers making long range groups just as small as expensive neck sizing dies reshaping cases to fit ultra tight chambers.

 

[Mikecr]

Bart, I'm not trying to change the heart & minds of those who FL size.
I realize someone using a 30-06, or running competitive 6PPC loads, needs to FL size. That NS only is not an option for them.

I am compelled however to remind reloaders that FL sizing is not always required, and that they do have some control over this. They don't have to shoot a 30-06 or compete in PB BR. There are also reloading advantages to minimal sizing, and in the long run it is easier.
Brass does not HAVE TO yield and grow with every cycle. That notion is flat out false.
Brass that is FL sized is not made the same every time, just as brass that isn't FL sized changes every cycle. But it's not automatic that all is true, or false, without further qualifications.

There was a time when most reloaders would insist that necks must be FL sized. But today, even while bushing sizing isn't perfected, no argument for FL sizing of necks would be accepted as best.
Did FL sized necks shoot good enough? YES.
Were FL sized necks best then? NO, they weren't.
And many today accept 'FL bushing dies', which aren't FL sizing dies at all. In fact, they can amount to exactly what I use -seperately(somehow offending).
Or, they could amount to pure crap if not fit to the chamber & load well.

Also, my headspace numbers are just that. There are no fudge factors or other clearances. On primer strike my cases move forward 0.0005-0.001 and then we'll just never know from there. But I know it don't matter from there, and that I don't have to worry about it.
If I were to guess what happens with cases that are FL sized, it would be that a loose shoulder on a high runout case rattles off first contact in an abstract direction. If the loaded round(including seated bullet) is truly straight, the neck-shoulder junction would stop the forward motion, but less consistently(given shallow angles) than cases held to tight and consistent headspacing. But I can think of no way to prove it.

 

[Bart B]

On primer strike my cases move forward 0.0005-0.001 and then we'll just never know from there.

My case necks are pushed against the shoulder before the primer strikes. The cases have between 26 and 30 pounds of force holding them there after the primer strikes. That impact force even sets the case shoulder back a thousandth or more before the primer fires. I doubt case shoulders will bounce off the chamber shoulder; they stay there while the round fires. And bullet straightness isn't an issue. the case neck's well centered in the chamber neck when the primer detonates; even with 4 thousandths clearance all the way around the neck.

If one reduces loads 1 grain at a time on rimless bottleneck cases, when the charge is down by about 10 percent or so, the primer will start protruding out of its pocket. It does that 'cause the case shoulder's pressed hard against the chamber shoulder and the case body behind the shoulder's hard pressed against the chamber wall at that point. Meanwhile, the back of the case is stretching back and pushing the primer out until it stops against the bolt face. Only when there's enough peak pressure to do so will the primer get pushed back into its pocket as the case head gets pressed against the bolt face. Weaker loads won't push the back of the case all the way back so the head stops against the bolt face; the primer in that fired case sticks out a bit.

But you're sure making me think about all this stuff I experimented with. I don't think I've forgot any of it.

 

[Mikecr]

Good stuff Bart
I should do some experimenting here as well.

I need to see where and at what angles my bumps are applying, and w/resp to my measurement datums. I wonder right now if I'm actually doing as good as possible with bumping.

 

[Bart B]

Few folks realize that with an in line plunger style ejector when the bolt's closed, all chambered rounds are pushed forward until they stop at the headspace point. There's enough clearance between the bolt face and extractor to let this happen; case rims are thinner than the space. Rimless bottleneck cases stop with their shoulder against and perfectly centered at the chamber shoulder providing the clearance around the body-shoulder junction allows this to happen.

As there's no such thing as perfectly round cases or chambers, when cases get diameters big enough at the front of the body, they'll start interfering with perfect centering of the case shoulder in the chamber shoulder as they stop against the chamber.

This is why folks who properly full length size fired cases get the great accuracy they do. It doesn't matter how much clearance there is between the case head and bolt face when the round fires. So a couple thousandths spread in case headspace is of no concern. As long as the bolt closes freely without binding on the case head causing the bolt to shift a bit on its locking lug surfaces and goes in battery the same way for each shot.

 

[BountyHunter]

Mike CR

As far as trimming, I find no benefit in even checking much less doing it. If the brass fits in the chamber without crimping at the mouth, it is long enough and not too long.

If you are not checking trim length, and only reloading four cartridge, and your definition of FL sizing has to do with trimming, and NOT FL sizing the body as you do (albeit with a honed body die), well I can see where your semantics are confusing to normal reloaders.

Those are not the normal reloader definitions. Sizing the body and sizing the neck is considered FL sizing. Yea yea you only "partially resize the neck." Trimming is trimming, but seeing as how you do not even check trimming; well thats another story but kind of puts it all in perspective as to the usefullness of this "semantical methodoligy" for LR hunting reloading with the cartridges normally used compared to what you reload.

Try telling everyone from now on, you just consider FL sizing equating to trimming, and you really do size the body with a body die.

 

[Mikecr]

I don't know where you dug up the quote, but if mine, you've taken it out of context.
My stance on trim length is to keep the mouths close to chamber end for quickest sealing.
With this, I don't just wholesale trim to some book length, but minimally, based on the chamber.
It is very rare for my trim lengths to change with reloading cycles, and so I don't worry about it like a lot of people have to. I don't benefit from worrying about it.

As far as body sizing, you need to understand that I don't typically need body sizing other than shoulder bumps. SIZING, is not merely contact, or squeezing a bit within springback, but actually changing brass dimensions.
I've made this clear in my posts in so many ways..
If I had gone with an extreme shoulder angle on my 6.5wssm, I could have gone 6 lifetimes shooting it's brass without ever inserting cases into ANY sizing die.

When you do size the bodies, cases lengthen, and actual FL sizing causes this.
If your cases aren't getting longer with reloading cycles, then you are not FL sizing I don't care what you call your die.
So other than direct measure, case length change is a good indicator of sizing action.

This is not a conspiracy BH. Chill out

 

[BountyHunter]

Mikecr

http://www.longrangehunting.com/forums/f28/case-lenghth-measurements-important-51642/index2.html post #11

Your quote so kind of hard to take it out of context. It is what it is.

I do not believe it is a conspiracy, just disengenous and totally misleading to shooters trying to figure out what to do with you constantly saying "NS only NS only" without all the very important caveats that are now out. In reality, you are referring to trimming and with a limited number of smaller cartridges that are not even LR cartridges.

Plus there is no documented testing corroborating your thesis and in fact everything contradicts it when you consider large cartridges at near max levels that have to be totally reliable in hunting or LR competition guns. Oops I want a "do-over" is not in this game.

You order a die from a LR smith with a build, and you will get a FL die maybe with bushings maybe without BUT NEVER a NS only die. Some of these guys have been building LR guns for 40 years and cannot afford to build something that will not work. If NS only would work they would do it, but it does not.

Now if you want to say "NS only, But use a body die, limit it to these four non LR cartridges and at these less than max PSI and velocity, and I cannot nor will I provide any documentation to prove this theory" then have at it and LET THE BUYERS BEWARE.