Best concentricity sizing method I have used

[hounddawg]

as long as we are asking questions no one can really answer

- at what point in the bullets travel has the case expanded to the point where there is zero clearance between the case and the chamber walls ?

- just to use made up numbers lets presume the case is .001 smaller than the camber and sitting on the bottom of the chamber with the bullet angled up at at a angle of .001 degrees. Would not it be better to have the concentricity of the bullet as close to 0 as possible so the that the bullet is always exiting the cartridge at the same angle every firing?

- would not a target barrel have less clearance between the cartridge and the chamber than a M1 surplus with the original barrel ?

 

[HiBC]

OK,here is another variable Bart has often mentioned.Bolt face squareness,cartridge head squareness. Either out of square you have the leaning tower of Piza.

Something I never did,just an imaginary solution to a problem that may not exist...
Alter a belted magnum chambering reamer so the belt face and its seat in the chamber are matching 45 degrees. The belt would seat in the chamber like a valve in a cylinder head in an engine.
The cases would have to be altered with a lathe and collet.Head clearance held close to zero.
That should center the case head in the chamber.If the shoulder centers ,the cartridge would theoretically be between centers,

 

[hounddawg]

fine stuff for a winters day discussion over a adult beverage in front of a warm fire but nothing but pure speculation. Maxwell pointed out above tiny tiny groups are shot on a regular basis at 100 yards with things just as they are. There has to be clearance between the case body and neck and the chamber, that's a given. How the bolt and extractor hold the case when the bolt is enclosed be it at a angle or parallel to the bore I cannot change and my XRay vision is out for repair so I won't even bother speculating on.

What I can do is make sure that the bullet is a parallel to the case as I can make it, that my bolt face is square and my technique is solid. That and pray to the gods of wind and mirage not to put a unseen gust of crosswind at 600 yards by sacrificing thousands of round in practice

 

[Bart B.]

It's easy to see all the spring loaded parts of the action that push the cartridge that's in the chamber.

Check them out in your rifle; magazine, firing pin, extractor and bolt face ejector.

 

[Maxwell Haus]

I keep it simple ,no ejector and size my brass to a light "crush" fit . Some bullets are jammed, so that helps . If things were very crooked they just just got as straight as my chamber when I closed the bolt.

 

[Bart B.]

I keep it simple ,no ejector and size my brass to a light "crush" fit . Some bullets are jammed, so that helps . If things were very crooked they just just got as straight as my chamber when I closed the bolt.

Doesn't the extractor claw against the case push the case body pressure ring off center against the chamber?

When neck only resizing was popular in the early 1960's, when the bolt was a small crush fit, accuracy got worse. Full length sizing setting the case shoulder back a couple thousandths fixed it for a few more neck only resizing routines.

The bolt goes into battery repeatable from shot to shot when nothing binds it up.

 

[Maxwell Haus]

Doesn't the extractor claw against the case push the case body pressure ring off center against the chamber?

When neck only resizing was popular in the early 1960's, when the bolt was a small crush fit, accuracy got worse. Full length sizing setting the case shoulder back a couple thousandths fixed it for a few more neck only resizing routines.

The bolt goes into battery repeatable from shot to shot when nothing binds it up.

Sorry, I am bored with this . You win . You don't even know what rifle I am talking about , you sure do like to debate.

 

[Bart B.]

Sorry, I am bored with this . You win . You don't even know what rifle I am talking about , you sure do like to debate.

Apologies for upsetting you. I used to think like you are. Then the match winners and record setters straightened me out. I wanted to pass good stuff on to you.

 

[Bart B.]

How the bolt and extractor hold the case when the bolt is enclosed be it at a angle or parallel to the bore I cannot change and my XRay vision is out for repair so I won't even bother speculating on.

Cartridge cases headspacing on their shoulder don't lay in the chamber bottom when fired. There's one or two spring loaded parts in the bolt that raise the case off the chamber bottom before firing.

 

[hounddawg]

There's one or two spring loaded parts in the bolt that raise the case off the chamber bottom before firing.

isn't that pretty much what I said? I have to agree with Maxwell, you sure like to debate, even when there is no one disagreeing. Reminds me a lot of another poster who disappeared from here

I am going to go out on a limb here Bart and state that I bet most of the readers of this forum are aware of how a bolt works. Just speaking for myself I would rather spend my effort on things I can control rather than things I cannot

 

[Bart B.]

isn't that pretty much what I said?

No. This implies you have no idea. And are not interested in learning.

How the bolt and extractor hold the case when the bolt is enclosed be it at a angle or parallel to the bore I cannot change and my XRay vision is out for repair so I won't even bother speculating on.

 

[hounddawg]

lol sure, why worry about what cannot be changed, that's a waste of life

was just cleaning a couple of my rifles from last range session and looking at the bolt how the case interfaced with the bolt face. The extractor would be at 3 o'clock and the ejector at 7 o'clock so when the bolt is opened the case is pushed up and to the right. No idea how much and really don't care since it is what it is and cannot be changed.

 

[Bart B.]

lol sure, why worry about what cannot be changed, that's a waste of life

was just cleaning a couple of my rifles from last range session and looking at the bolt how the case interfaced with the bolt face. The extractor would be at 3 o'clock and the ejector at 7 o'clock so when the bolt is opened the case is pushed up and to the right. No idea how much and really don't care since it is what it is and cannot be changed.

You can remove the ejector.

You can grind off part of the extractor claw a little bit and still be able to get the case pulled out of the chamber.

 

[Bart B.]

...delete...

 

[Nathan]

Never heard of sizing with the die loose.

Before the die is set, I leave the lock ring loose. I’ll size a case and adjust with it loose until I get the setting right. Then I lock it down. I might size and turn 10 times before I get it perfect....then lock that setting in with the lock ring. I’ve been doing this with success for 25 years or so.

As you sneak up on a perfect adjustment, you lock the lock ring every time?

BTW, I found a thin machined bushing for holding die square when locking down. Just at the local hardware store.

 

[Maxwell Haus]

isn't that pretty much what I said? I have to agree with Maxwell, you sure like to debate, even when there is no one disagreeing. Reminds me a lot of another poster who disappeared from here

I am going to go out on a limb here Bart and state that I bet most of the readers of this forum are aware of how a bolt works. Just speaking for myself I would rather spend my effort on things I can control rather than things I cannot

You are a very polite person , I would have called him a troll . When a guys keeps coming at you and you know he does not have a clue of the actual situation, that is a troll.

 

[HiBC]

I appreciate that Bart has history of being a World Class shooter and part of the US Navy shooting team. That gave him access to resources ,research,and experimentation far beyond the means of most of us.

The other thing about Bart I have noticed is a style of asking a question.Its seldom about a whizzing contest.
The question is designed to nudge me slightly out of my comfort zone and think.
Thats all. They are Mentor like questions. I have to go back and re-evaluate my thoughts. Its not about winning or losing.

Its about maintaining just enough humble to learn something new once in a while.I have no doubt behind many of Barts questions is a trail blaze he put there so I/we can find the path to our own discovery.
I get that,and I appreciate it.

And...I also believe my own experience . Example? Under the forces of a press at full load do the 5 or 6 threads of the lock ring tightened on the machined top of the press provide the squareness and centered reference? Remember the load the ram is applying to the die is trying to lift the lock ring off the press.As the lock ring is static.any lift is clearance between the lock ring and press or die threads.

The 7/8 -14 threads have some clearance so the die screws in the press easily. The lock ring serves to take up the slack,and hold the loadbearing surfaces of the threadform in contact. I'll say again,a 60 degree thread form can be looked at a lot like a tapered valve seat.An exhaust valve will settle square and centered in the seat.Thats two dimensional.Add the helical nature of the vee thread,the length,and you add in the third dimension.

Mating Vee threads want to self center and self square under load. Its best the lock ring does not compete. It will lose. The resilience of an O-ring will sustain a preload while allowing the 7/8 - 14 thread axis to be Master.

 

[Bart B.]

Here's something to consider about shaping and sizing dies making cases and bullets from sheets of copper and brass.

None have O-rings between the lock ring and press frame.

 

[hounddawg]

take a unsized case color web with a sharpie then FL size it. At the top of the stroke see if there is any clearance between the die mouth and the top of the shellholder. Using a Whidden die ain 6BR I could not get a piece of paper between top of the shellholder and the die base. When I lowered the ram the sharpie was worn off to the top of the extractor groove. Just one die and cartridge but in that instance the entire case from the extractor groove up was in a press fit in a chamber cut with a one piece reamer.

Pretty sure that float in the dies and the shell holder would not affect that cases neck to body concentricity in the least. You could mount that die at a angle as long as there was enough float in the case holder where the case rim was not hitting the top of the caseholder groove and bending the case rim and it would not matter. Worst scenario is the case rim would get bent becasue that is least thick part of the case protruding from the die

you guys need to stop and think about how a die, the case and the shellholder interact. That float designed into the case holder is there for a reason

 

[hounddawg]

You can remove the ejector.

been there done that on my single shots. Not real practical on repeaters or gas guns

You are a very polite person

nope just been smacked on my hand enough by forum mods to where I tread carefully

I appreciate that Bart has history of being a World Class shooter and part of the US Navy shooting team.

If Bart posts something about a Springfield or a Garand you can pretty much bet it is gospel and dead on. However a lot of things have changed in the sport in the last 40 years and he and I tend disagree at times on newer stuff but I always try and be polite in my disagreements and he does have a lot of good advice at times.