Full Length or Neck Only; What's Best Resizing for Accuracy?

[Bart B]

Full length sizing is the rage now.

It was the rage starting in the late 1950's with handloads producing best accuracy. Nothing new these days.

 

[Orange Dust]

Sorry
I must have missed your post. Normally If I see a post that is pretty much like I would post I give them a like and move on.

J E CUSTOM

No worries, you did a better job anyway

 

[Alibiiv]

No worries, you did a better job anyway

You did a good job too, appreciate everyone's input on a question and every person's knowledge/experience. That's what this forum is about.

 

[bigedp51]

Germán A. Salazar forgets to mention the primary case part that centers the cartridge neck in the chamber neck. If the case neck is centered on it. It's the closest fit anywhere and its not the bullet or case neck.

It's the case shoulder physically centered in touching the chamber shoulder. If the case neck is centered on the case shoulder, it's centered in the chamber neck. The bullet goes along with it.

His diametrical clearance at the case web is misleading because that part of the case in front of the extractor groove is typically pressed against the chamber wall by the spring loaded extractor. Which means the case is a tiny bit crooked in the chamber.

So you are telling this forum you know more about shooting and reloading than Germán A. Salazar.

In my opinion Bart B. there are too many midgets sitting at their computers pretending to be giants.

Show us your reloading webpage Bart B. and the articles you have written at accurateshooter.com.

 

[Bart B]

So you are telling this forum you know more about shooting and reloading than Germán A. Salazar

Yes. Regarding what centers bullets in barrels when fired. It's simple grade school reasoning. And physically measuring what happens to do it can be done.

 

[birdiemc]

So you are telling this forum you know more about shooting and reloading than Germán A. Salazar.

In my opinion Bart B. there are too many midgets sitting at their computers pretending to be giants.

Show us your reloading webpage Bart B. and the articles you have written at accurateshooter.com.

One way to test that out might be to cut off a barrel just ahead of the lands, install it on an action and chamber a round. Take all the measurements possible, then cut it back to the neck area of the chamber and repeat, then cut the neck off and repeat. Past that would be pointless since you lose the shoulder, but a cutaway could shed some light on the issue.

 

[Bart B]

One way to test that out might be to cut off a barrel just ahead of the lands, install it on an action and chamber a round.

I mentioned this in post #36.

Same thing happens when you push two Dixie cups together. That's why I dubbed this scenario the Dixie cup syndrome. Simple and easy to understand.

 

[Mram10us]

Doesn't the firing pin drive the case forward until it stops against the headspace reference then dent the primer .025" or more to fire the round?

Often, case shoulders are set back a thousandth or more before the round fires.

Apologies, I just realized I didn't respond. With Rem 700s, I thought the ejector pushed the case forward in the chamber against the shoulder, thus no gap in the front section of the chamber. Whatever gap behind the case, hopefully .002" in my case, but too much can cause misfires and definitely more room to slam back against the boltface causing separations.

 

[J E Custom]

Apologies, I just realized I didn't respond. With Rem 700s, I thought the ejector pushed the case forward in the chamber against the shoulder, thus no gap in the front section of the chamber. Whatever gap behind the case, hopefully .002" in my case, but too much can cause misfires and definitely more room to slam back against the boltface causing separations.

You are right about the ejector pushing on the case. the extractor will restrain the case some and prevent it from moving to far forward. If the case is over sized the ejector can cock the case in the chamber maligning the bullet. If the shoulder is bumped to far the extractor stills holds the case near the bolt face. (How near depends on the extractor tolerance to the case extractor groove).

When setting the final head space, the ejector has to be removed to prevent false readings. There will always be a little head space before firing because of the ejector taking up any slack in the extractor system, and based on the amount of sizing performed. After firing there should not be any head space and the ejector or the extractor wont have any effect on the case head to shoulder dimension and as long as the case doesn't get over sized, the case head should be square to the bolt face.

J E CUSTOM

 

[Mram10us]

JE,
Definitely a good point about removing the ejector and firing pin mechanism when doing any measurement tied to headspace of chamber or cases. I saw a video on YouTube where he was trying to find the coal without removing them. Alex wheeler has the best video in my opinion

 

[bigedp51]

Yes. Regarding what centers bullets in barrels when fired. It's simple grade school reasoning. And physically measuring what happens to do it can be done.

The bullet is in the throat long before the case shoulder touches the shoulder of the chamber. And you are assuming the rifle's chamber, the cases shoulder and the resizing die all have the same exact shoulder angle. Meaning a circle within a circle contact area will not center the bullet when its already centered in the throat.

This posting by you is nothing more than you stroking your ego and your cone within a cone centering the bullet theory. And you are the only person posting this information on a "cone within a cone" on the entire internet. Your Dixie cup syndrome is a leftover from wearing a too tight Navy Dixie cup hat.

And you were laughed out of accurateshooter.com reloading forum the last time you brought it up.

 

[Mram10us]

The bullet is in the throat long before the case shoulder touches the shoulder of the chamber. And you are assuming the rifle's chamber, the cases shoulder and the resizing die all have the same exact shoulder angle. Meaning a circle within a circle contact area will not center the bullet when its already centered in the throat.

This posting by you is nothing more than you stroking your ego and your cone within a cone centering the bullet theory. And you are the only person posting this information on a "cone within a cone" on the entire internet. Dixie cup syndrome is a leftover from a too tight a Navy dixie cup hat.

And you were laughed out of accurateshooter.com reloading forum the last time you brought it up.

Can we all agree that the ejector is pushing a properly sized case into the shoulder of the chamber?
Edit: since the brass obviously has flex, is it safe to say the brass shoulder will form to the chamber shoulder due to pressure by the bolt closing or the initial expansion of gases, before the bullet ever touches the lands?

 

[Bart B]

And you are assuming the rifle's chamber, the cases shoulder and the resizing die all have the same exact shoulder angle. Meaning a circle within a circle contact area will not center the bullet when its already centered in the throat.

You're wrong. Twice.

All bullets do not touch the throat lands when chambered.

Rarely do chamber shoulder angles exactly match case shoulder angles. That doesn't prevent the case shoulder centering in the chamber shoulder. Can you can figure out why? There's a picture in this thread showing the two angles. You put it in post #133.

 

[Mram10us]

And you were laughed out of accurateshooter.com reloading forum the last time you brought it up.

This shouldn't have any part of a productive discussion. We only learn and get better if we debate differing views.