full length resizing

Mikecr

Well-Known Member
Joined
Aug 10, 2003
Messages
5,821
Location
NC, oceanfront
There is no actual measure BUT where your chamber/bolt tells you.
And starting against the shell holder may be too far to begin(what Canadian is saying).

What actually does happen to some reloaders, is they start with the die too far down and further adjustments act to reduce headspace for the wrong reasons. Here, their shoulders start squishing forward because they're way oversizing the body. They've gone past bumping -toward reforming.
This is why a general starting point, if there were one, would be conservatively above the shell holder and sneaking into proper bump (as felt by chambering with the spring removed).

With the right bump, you get a shoulder measure with your gizzy & log it. I sneak into the first case sizing until matching logged bump, every time. I do this by hand tightening a set die/lockring which is very close. Then I snug it with a wrench until sizing is right on the money. With some combinations there is slight cam over. With others there is light between the shell holder and die bottom.
I suppose slight cam over would be desired to take out press slack. But desired bump/sizing is my 1st priority for sure, and I do measure every case sized, just as I measure every bullet seated.
For peace of mind, I'll randomly cycle a case through the chamber. If it ain't right, I'll know it.

A tip: If your loading lower shoulder angle(<30deg) ammo and you know it won't be used for a couple months or more, give the shoulders the full 2thou max.
Some of that bump counter springs back over time, and you don't want to gall a lug with stiff bolt closer out there on a hunt.
 

Edshock300

Member
Joined
Nov 17, 2013
Messages
8
Location
Grande Prairie Alberta Canada
Thanks guys I've been reloading for a few years now, and have always set my die's to the shell holder.
it seems anytime my brass fails its the head space that cracks, so I guess its not something i am doing wrong.

thanks again
 

AZShooter

Well-Known Member
Joined
Dec 12, 2005
Messages
2,774
Location
Tucson Az
Edshock300,

"Thanks guys I've been reloading for a few years now, and have always set my die's to the shell holder.
it seems anytime my brass fails its the head space that cracks, so I guess its not something i am doing wrong."

YOU ARE DOING SOMETHING WRONG!

If the case is cracking just in front of the web the sizing is done incorrectly. I guess all earlier posts on how to set up the die was misinterpreted.

OVERSIZING IS A DANGEROUS PRACTICE AS THE BRASS CAN FAIL AT SOME POINT!

Here is why the case is splitting near case head. When the brass is fired it expands to conform to the shape of the chamber. There is a tiny bit of springback of the brass allowing easy extraction.

If the only the case's neck is sized to hold a bullet it can fit back into the chamber for at least one to possibly three sizings with some bolt closure resisitance. At that point body sizing is required to close the bolt.

Other type of actions require full length sizing for every reload. Autoloaders require some over sizing to ensure they will fit.

Bolt action hunting rifles that require a fast second shot may not work as easily with cases that fit as snugly as a neck sized case. This is where full length sizing is used.

If the die is set up so the brass's shape is over sized it will fit easily into the chamber BUT the brass will be over worked. The next firing will lengthen the case to again fit the chamber. Subsequent full length sizing will cause the brass to flow towards the neck area lengthening the case. The case's length will have to be trimmed. The brass flows from the area in front of the web and will do so until it gets so thin the case cracks (called incipient case separation) or breaks off! This is a dangerous situation as hot gasses will vent through the action! Many rifle designs will vent off these gasses but some rifles can send the gasses back into the shooter's eyes!!!!

It is imperative to either full length size a case correctly or throw it away after two or three full length sizings where the die has over sized a case.

Don't know how to make this more plain.

OVERSIZING IS A DANGEROUS PRACTICE AS THE BRASS CAN FAIL AT SOME POINT!


Having to trim several times will give a shooter a clue that the case is getting thin near the web. Sometimes a circular mark will show just infront of the case web a tell tale sign that the case is about to let go.

Hope this helps anyone with the problem of case head cracking or separation now know how to prevent it.
 

Mikecr

Well-Known Member
Joined
Aug 10, 2003
Messages
5,821
Location
NC, oceanfront
Actually, you don't always have to FL size, and it isn't always desired. It depends on the cartridge & chamber & loads.
FL sizing requirement is another fallacy, like having to cam over at the shell holder..

With reloading we should do what we need to locally -that's right.
Never take reloading manuals literally.
 

lever-hed

Well-Known Member
Joined
May 8, 2008
Messages
248
Location
Ohio
Mikecr – I’m all for safety, no issues there, but for you to say never take reloading manuals literally is misleading and frankly incorrect. Reloading manuals are there for safety first and foremost. They are also written for the average shooter/reloader. They are not written expressly for benchrest or any type of custom situation, although they are getting better.
The paragraphs below are taken right from the Sierra manual.. so if this is incorrect, tell us again, why should we not take reloading manuals literally?

Sierra Rifle and Handgun Reloading Data (Edition V) –

“Full Length Sizing” (pg 151) -- ..”Adjustment of the full length die calls for the die body to be screwed down in the press until it contacts the shell holder at the top of the ram’s stroke. If the ammunition is to be reused in the same gun the cases were originally fired in, back the die off ½ to ¾ of a turn and size a lightly lubricated case. Wipe the case dry, and chamber it in the gun. If any resistance is felt, lower the body die another 1/8 of a turn (or less), and repeat the process with another fired case. This is repeated until the action will just close without resistance. …This method will ensure that the fired cases are resized with a minimum amount of headspace.”

“Excessive Resizing” (pg 153) – “Instructions included with most die sets suggest screwing the die body down until it contacts the shell holder…” ..”While this may be necessary when the ammunition being loaded will be used in a number of different firearms, we strongly recommend that resizing dies be adjusted using the first method described in the ‘Full Length Sizing’ section whenever possible.”
 

SidecarFlip

Well-Known Member
Joined
Dec 12, 2011
Messages
4,442
Location
S.E. Michigan
Myself, I keep 2 reloading manuals handy, the Sierra because I load Sierra pills and I buy direct from them and Hornady because my small bores (22 caliber) are all loaded with Hornady pills.

I've seen that in the Sierra loading manual but I use a Hornady headspace gage on the shoulder datum to gage headspace. Much easier than chambering rounds.

Any die (insert or solid) will set back the shoulder depending on how close the bottom of the die is when the ram is at it's upmost position.

You can also alter how far the die bumps the shoulder by grinding off the base a couple thousands (which I do).

Most times you can achieve enough bump without grinding but that depends on the particular chamber.

I just ran through 2500 LC 2005 match brass cases over the last week, so my fingers are a bit tender.:D
 

Mikecr

Well-Known Member
Joined
Aug 10, 2003
Messages
5,821
Location
NC, oceanfront
I use a Hornady headspace gage on the shoulder datum to gage headspace. Much easier than chambering rounds.
Easier, but not accurate. Well, unless Hornady chambered your barrel and had fireformed your brass for you.
When you say "on the shoulder datum", I hope you realize there is no shoulder datum other than what you establish locally. Maybe that's what you meant while using a Hornady gage.
You don't need Sierra manuals for Sierra bullets, and Hornady manuals for Hornady bullets.
I haven't had/used a reloading manual in 35yrs(since reloading class in HS).

Also, you cannot predict bump. It is a trial & error determination, that is independent of ram, or shellholder, or shims here or there.
 

SidecarFlip

Well-Known Member
Joined
Dec 12, 2011
Messages
4,442
Location
S.E. Michigan
Been working just fine for me, for years. I use a case from the particular chamber to gage the datun dimension wihich remains constant because the bore of the gage is unchanging so it locates in the same spot every time and the die inetrior dimensions don't change either. All fired cases are returned to the corresponding box and that box is marked as to the firearm used in. That way, I have the cases segregated already, after the initial firing.

My credo is, I load my way and my reloads don't blow up in my face (or out the vent holes in the receiver).

My regimen seems to work just fine, I'm the designated reloader for our entire group and thats a whole bunch of diverse calibers across a bunch of rifles. Everything from 223 to 338 and handgun loads too.

I'm preferential to straight walled cases in handgun loads. Much easier to deal with and less intensive but harder to trim, when needed infrequently.

There are a myraid of ways to achieve your desired result and so long as you achieve that without incident, all is good.
 

MagnumManiac

Well-Known Member
Joined
Feb 25, 2008
Messages
3,973
If this point is past -.002" past the required headspace to fit your case back into the rifle you are reloading for, you have already overworked the brass. If the die is touching the shell holder ,with the slop removed, when sizing a case how much farther can you push the case into the die?




This is proper procedure for exact fit and longest case life.
To answer your question correctly, the case WILL NOT fully enter the die UNTIL ALL SLACK IS REMOVED FROM THE LINKAGES IN RCBS PRESSES WITH RCBS DIES. CAMMING OVER is necessary to get the die touching the shellholder when a CASE is installed in the die.
Other die manufacturers have different set up procedures, so do different press manufacturers, the easiest method to avoid trouble is to follow the manufacturers instructions. If you do this, you will be able to tweak your dies to get the best headspace for YOUR RIFLE.
If you want precise headspacing I recommend buying a RCBS Precision Mic for your caliber in question and set your dies up with measured ACCURACY, guessing is just that in most instances.

Cheers.
gun)
 

Canadian Bushman

Well-Known Member
Joined
Jan 24, 2012
Messages
1,814
Location
Houston, Texas
the case WILL NOT fully enter the die UNTIL ALL SLACK IS REMOVED FROM THE LINKAGES IN RCBS PRESSES WITH RCBS DIES.

Im not arguing this. This is true for every press with any die.
Im saying creating more resistance as the press cams over by screwing the die down more, is not necessarily pushing the case further into the die.

CAMMING OVER is necessary to get the die touching the shellholder when a CASE is installed in the die.

This is not true and it is beside the point i was trying to make.
Some cases, when being sized in a particular die, do not need the die to contact the shell holder in order to have the headspace bumped back enough to properly chamber in the rifle they are being sized for.

If you set up your die by contacting it to the shell holder, there is a good chance you could be overworking the case.

The "CAM" is the most upward part of the stroke of your press's arbor.
When you reach this point the press handle is moving the greatest distance relative to the distance traveled by the arbor. You always want to run through this point on any press operation because it assures your arbor is reaching its highest point with the greatest amount of force. This is regardless of the amount play you have in your arbor or its alignment to the die. If the seat is contacting the bottom of the die at this point and you are feeling resistance in the handle, chances are the case is as far into the die as it will be able to go.

In my opinion screwing the die down any further is only stressing the components of your press. You would benefit more from running the case through the die a second time or even removing material from the base of the die or the top of the shell holder, than you would by screwing the die down any further.
 

Edshock300

Member
Joined
Nov 17, 2013
Messages
8
Location
Grande Prairie Alberta Canada
Thanks guys I've been reloading for 20 years now and had 50 rounds in my 30-06 chamber hard after they were reloaded as if I only neck sized them not sure what happened there but it confused me because it has never happened to me before, I reload for 30-06,308, 223, 45-70, 357 mag and never encounter that before, I haven't shot those rounds out of my 30-06 yet will it be safe? most likely they will just get stuck in the chamber right.
 

Canadian Bushman

Well-Known Member
Joined
Jan 24, 2012
Messages
1,814
Location
Houston, Texas
In my experience you have to have a really tight fit and a pretty hot round to stick one in there. Ive neck sized rounds until they were downright difficult to get into the gun. They shot just fine with no pressure signs and extraction wasnt horrible but i had to tug on the bolt a bit to get it out. Every now and again i would have to tap on the handle a bit to get one out.

I dont recommend loading like this and it was an accident when it happen to me, but other than a little wear on the rifle its harmless.

Now when i get a batch thats hard to chamber i run the loaded shell through a body die and im back in business.
 
Top