Neck Sizing Vs. Full Length Sizing and Neck Tension

[C-130 Dude]

Yep, if you let those primer pockets get too dirty, it can take gorilla force to seat them or you can crush and ruin them when they get cattywampus. So, I think every so often at least better brush them or scrape them out w brush or reamer.

I do it everytime just to make it easy to seat them.

I had the unfortunate occasion to have a primer detonate while I was over pushing in many years ago. Scared the ever livin' crapola outta me! Changed my cleaning prep process right there and then! My ears rang for a month! My wife still says that's why I'm deaf.......

 

[C-130 Dude]

Before everyone here head explodes look up the science guy who test reloading equipment scopes,etc . He tested primers by height and seating depth. From, from .121 height to .131 and media group of .126 shot them all , after long winded explanation it made no difference! He crushed them, set them just touching the back of the pocket and just off touching the back of the pocket. No differences!

EDITED:
I'm getting ready to test a batch in the next week. A little different type test.

Posted a different thread about my test.

I'm not going to hijack the op thread. Apologies.

Will report back.

 

[Rosebud]

I'm getting ready to test a batch in the next week. A little different type test.

Purpose of test is see if there is any difference between cases that have a .127 pocket and cases having a .130 pocket depth. All primers will be seated .003 -.005 below case head. I am using -14, -15, and -16 LC 308 cases. All cases are full length sized with neck sized bushing using the RCBS Match Master dies. Powder is IMR 4064, primers are CCI 34, and bullets are 175 SMK AND 168 SMK. 70 rounds each bullet weight. Powder charges will increase from 42.5 to max of 45.0 at .5gr increments. These cases are new, never fired. I'm curious to see differences (if any). Expecting overpressures at some point and primer issues also. Testing limits of applicability. We'll see.....

Will report back.

Looking forward to it!

 

[C-130 Dude]

Looking forward to it!

I posted a new thread on this. Not good to hijack the op thread. Sorry.

 

[436]

If you keep shooting those cases you will find out just how much those cases will stretch.

With both my .308 and .223 LR bolt rifles, I've put a lot of brass through both of them sized with an RCBS X-Die... I run my Laupa quite a few times. On my brass and have no complaints or any case separation, and case stretch has been very minimal. So far I've never seen the sign(s) of the "gold ring" of separation on the web once, usually, the primer pockets start to enlarge a bit and I call it a day with them or I held off too long on the annealing. I don't know, perhaps I'm just lucky.
Cheer's

 

[Dirtrax]

I'm getting ready to test a batch in the next week. A little different type test.

Purpose of test is see if there is any difference between cases that have a .127 pocket and cases having a .130 pocket depth. All primers will be seated .003 -.005 below case head. I am using -14, -15, and -16 LC 308 cases. All cases are full length sized with neck sized bushing using the RCBS Match Master dies. Powder is IMR 4064, primers are CCI 34, and bullets are 175 SMK AND 168 SMK. 70 rounds each bullet weight. Powder charges will increase from 42.5 to max of 45.0 at .5gr increments. These cases are new, never fired. I'm curious to see differences (if any). Expecting overpressures at some point and primer issues also. Testing limits of applicability. We'll see.....

Will report back.

You can't use new cases to test anything and get much in the way of valuable info.

 

[Dirtrax]

Belted magnums are reloaded exactly as any other case. Excessive headspace is the reason for failures. There are no tricks or special sauce required. Don't bump the shoulder for 2-3 firings measuring the datum each time and watch it grow just like a non-belted case. If fl sizing screw the die in fairly short of touching the shoulder as indicated by measurements until you get .002-.004" shoulder bump just like any other case. Now lock the die and you're done. If light loads are used neck sizing will go far, but if you're pushing it hard fl sizing will be your friend. I get 12-15 firings and I push my magnums. I don't lose many at that point but it's never from case head separation.

 

[C-130 Dude]

You can't use new cases to test anything and get much in the way of valuable info.

The purpose is not groups. It's difference in results of primer pocket depth. Not seating depth.

 

[C-130 Dude]

You can't use new cases to test anything and get much in the way of valuable info.

I should have never posted this on this thread. Not cool to hijack op thread. See new thread. Thanks.

 

[Mike Matteson]

With my super-x brass from the late '70s and early '80s I've FL sized every time. The same brass more than 10 times and some over 15.

You are lucky there on the Winchester brass. I would show case separation in 3 to 4 firing. That ended with neck sizing. A lot of people don't like belted mag because of the separations. I stubble on to it a great many years ago. Part of that was I was using a 300WM NS Die for my 308NM. It only size about 3/4 or so of the neck.
Now I haven't tryied bumping my case, but will give it try someday.
Neck tension: Most of that is by how they group using different tensions. There is several people that feel that tension needs to be set by first under sizing the neck, then using a mandrel to expand the neck out to the size they want to set tension. You will need to watch for spring back on the necks. It will show up in a couple of days, I believe. I don't have problems with that. I feel most aren't cutting their necks for thickness, so the uneven neck is being put into the inside of the neck. That is the reason I believe the use of the mandral is to push even portion back out to the outside of the neck. Now I contine that if the neck is even to start with it doesn't matter or no mandrel is needed.
I feel that cutting your necks for thickness and at the same time even the wall of the neck out so it's not needed.
Something else to work on!

 

[C-130 Dude]

You are lucky there on the Winchester brass. I would show case separation in 3 to 4 firing. That ended with neck sizing. A lot of people don't like belted mag because of the separations. I stubble on to it a great many years ago. Part of that was I was using a 300WM NS Die for my 308NM. It only size about 3/4 or so of the neck.
Now I haven't tryied bumping my case, but will give it try someday.
Neck tension: Most of that is by how they group using different tensions. There is several people that feel that tension needs to be set by first under sizing the neck, then using a mandrel to expand the neck out to the size they want to set tension. You will need to watch for spring back on the necks. It will show up in a couple of days, I believe. I don't have problems with that. I feel most aren't cutting their necks for thickness, so the uneven neck is being put into the inside of the neck. That is the reason I believe the use of the mandral is to push even portion back out to the outside of the neck. Now I contine that if the neck is even to start with it doesn't matter or no mandrel is needed.
I feel that cutting your necks for thickness and at the same time even the wall of the neck out so it's not needed.
Something else to work on!

I draw the line at turning my case necks.

 

[ARlife4me]

That's tough good brass. Wish I had a pile of it.

I wonder if other cases win produced were as good? I still reload pmc 44mag brass from the '80s (4,000 cases) that been reloaded 20 or more times, but not all made the cut..

 

[ARlife4me]

You are lucky there on the Winchester brass. I would show case separation in 3 to 4 firing. That ended with neck sizing. A lot of people don't like belted mag because of the separations. I stubble on to it a great many years ago. Part of that was I was using a 300WM NS Die for my 308NM. It only size about 3/4 or so of the neck.
Now I haven't tryied bumping my case, but will give it try someday.
Neck tension: Most of that is by how they group using different tensions. There is several people that feel that tension needs to be set by first under sizing the neck, then using a mandrel to expand the neck out to the size they want to set tension. You will need to watch for spring back on the necks. It will show up in a couple of days, I believe. I don't have problems with that. I feel most aren't cutting their necks for thickness, so the uneven neck is being put into the inside of the neck. That is the reason I believe the use of the mandral is to push even portion back out to the outside of the neck. Now I contine that if the neck is even to start with it doesn't matter or no mandrel is needed.
I feel that cutting your necks for thickness and at the same time even the wall of the neck out so it's not needed.
Something else to work on!

I run the brass all the way down to the shell holder every time I reload. Should I have done it differently,.........all of this reading has me wondering.

 

[foul bore]

I don't have a lot of experience case separations as I am pretty careful to avoid them, but it's my understanding that most cases will get thin and separate just above the case head simply because the case head is much harder than the rest of the case so there is a discontinuity in that area. That being said, I have experienced several case separations this past year, some even separated in my FL die. All were LC18 5.56 brass with about 3-4 firings, and all the cases separated right at the body/shoulder junction. I'm more inclined to think there is something wrong with that lot of brass, but it does provide some evidence that brass could separate pretty much anywhere. I think the main takeaway from the brass migration discussion is this: if your brass is getting longer and requiring a trim often, then it is getting thin somewhere, and that's not good. I once heard a general rule that brass should be scrapped after 3-4 trimmings (not firings) to prevent case separation, and I generally abide by this.

excessive shoulder bump will cause case head separation never exceed .004 .002 is prefered