Partial Sizing Mixed loads

Yosemite Steve · February 13, 2018, 08:56 AM

I have a batch of brass I am using to work up loads/ladders after being full length sized. I want to partial size (neck bump) this brass. Will it create inconsistencies if I do so because the brass was fired with different charges/pressures? Should I fire form all the brass with the same pressure first and then partial size? Said brass is Winchester 30-06 on it's third round of firing.

jamaica · February 13, 2018, 11:29 AM

"I want to partial size (neck bump) this brass."

Hmmm, not sure what you are asking here. You just said: " after being full length sized" Well full length sizing is just that! It sizes the neck too. Just load them!

Yosemite Steve · February 13, 2018, 12:12 PM

I meant that after firing them I want to partial size. I just read an article on fire forming that says to seat to the lands to keep them from moving forward. In the past I have used same lot brass for load work ups and then partial sized them. I fear that this may have created inconsistent brass because it was fired with varying pressures. I am thinking that the partial sizing might open a can of worms in regards to consistency.

F. Guffey · February 13, 2018, 12:44 PM

Quote:

I want to partial size (neck bump) this brass.

Neck bump

I hear many claims made by reloaders that they have been hand loading ammo for years, many claim they go back to a time before the Internet. And then there are the bumpers, they bump this and they bump that with no clue. I have bump presses, all of my bump presses are cam over presses because RCBS said the cam over press is a bump press; they also said if the press does not cam over it is not a bump press.

So now we are going to start bumping the neck and I wonder how is that possible?

Partial full length sizing? My presses and dies are designed to return a case to minimum length/full length size when the die is adjusted down to the shell holder with an additional 1/4 turn of the die, for those that keep up that would be .017". I do not insist on full length sizing, I am the fan off offsetting the length of the chamber with the length of the case. So to adjust the die when sizing the case a reloader should be able to determine the length of the chamber or they have to start by fire forming. And then there is measure before and again after.

I am the fan of using the feeler gage when adjusting the die to and or off the shell holder, many times I have asked if there is a reloader that knows the orgin of the .002" clearance and they respond with: well, WELL, I knew before I asked most of them discovered it all by themselves with no help.

Some reloaders use dimes to space the die off the shell holder, others use nickels and I wonder if they own a height and or depth gage.

F. Guffey

ammo.crafter · February 13, 2018, 12:52 PM

A Mercury dime is the best

Yosemite Steve · February 13, 2018, 12:53 PM

Guffey, I believe that this is for certain a situation where precision is very important. What I have done in the past for custom sizing was to measure from the lock ring to the base of the die for a certain setting. I know now that this does not create a precise situation. I am considering a set of Redding precision shell holders that have varied thicknesses so the cam over can be applied

jugornot · February 13, 2018, 04:57 PM

The shell holders only allow longer than the stock shell holder. If you have full length resized already they will not bump back any. After firing they will allow you to bump back less than the stock shell holder. If you are after consistency the full length resizing is the way to go. If you want to not bump the neck back as far, then the redding shell holders are for that.

HiBC · February 13, 2018, 05:05 PM

I suggest you not try to incorporate every side trail of information you find into your loading practice.
I take "partial sizing" as an attempt to neck size only with a full length size die.
Its not a good practice.The case body gets sized for diameter anyway.
Squeeze a banana in your hand,it gets longer.
You don't want to skip the part where the die restores the shoulder.
It might be that setting the die to hard contact the shellholder gives you excess head clearance.Its fine to use a feeler gauge between shellholder and die for a consistent setup. IMO,a dime is too much.It leaves the shoulder uncontrolled.
Long seating bullets MIGHT be a plan if you are fireforming Ackley improved's or something.
I suggest you not introduce a new variable with your seating depth.

Try to full length size them to .002 head clearance,you have decided on 3.320 seating depth,use it.
Just load them and shoot them. Nothing kinky required.
You might paper clip sort them after.
Consistency.

OzeanJaeger · February 13, 2018, 05:12 PM

IMHO if the rounds were loaded within the tables (or more) the pressure garadient between start load and max is always going to be limited by the chamber walls. The brass will snap and snap back uniformly for all intensive purposes.

Sort of like water is not compressible until the pressure is truely astronomical. So too with brass. Surely there will be some difference, but it’s so small so as to be immeasurable without a physics lab. IMO this will effect nothing.

I run ladders all the time, and consider those “fired”, and ready for match loading like all the rest.

std7mag · February 15, 2018, 06:25 AM

Steve,

Your way over thinking this.
Get a Lee neck sizing die and be done with it.
Make sure you segregate your casings per rifle though. (Savage, 1903, etc)

February 13, 2018, 08:56 AM	#1
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	Partial Sizing Mixed loads I have a batch of brass I am using to work up loads/ladders after being full length sized. I want to partial size (neck bump) this brass. Will it create inconsistencies if I do so because the brass was fired with different charges/pressures? Should I fire form all the brass with the same pressure first and then partial size? Said brass is Winchester 30-06 on it's third round of firing.

February 13, 2018, 12:52 PM	#5
ammo.crafter Senior Member Join Date: June 25, 2006 Location: The Keystone State Posts: 1,970	die sheholderll A Mercury dime is the best __________________ "Peace is that brief glorious moment in history when everybody stands around reloading". --Thomas Jefferson

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February 13, 2018, 11:29 AM	#2
jamaica Senior Member Join Date: March 24, 2006 Location: Northern Utah Posts: 705	"I want to partial size (neck bump) this brass." Hmmm, not sure what you are asking here. You just said: " after being full length sized" Well full length sizing is just that! It sizes the neck too. Just load them!

February 13, 2018, 12:12 PM	#3
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	I meant that after firing them I want to partial size. I just read an article on fire forming that says to seat to the lands to keep them from moving forward. In the past I have used same lot brass for load work ups and then partial sized them. I fear that this may have created inconsistent brass because it was fired with varying pressures. I am thinking that the partial sizing might open a can of worms in regards to consistency.

February 13, 2018, 12:53 PM	#6
Yosemite Steve Senior Member Join Date: December 27, 2017 Posts: 460	Guffey, I believe that this is for certain a situation where precision is very important. What I have done in the past for custom sizing was to measure from the lock ring to the base of the die for a certain setting. I know now that this does not create a precise situation. I am considering a set of Redding precision shell holders that have varied thicknesses so the cam over can be applied

February 13, 2018, 04:57 PM	#7
jugornot Senior Member Join Date: September 20, 2017 Posts: 197	The shell holders only allow longer than the stock shell holder. If you have full length resized already they will not bump back any. After firing they will allow you to bump back less than the stock shell holder. If you are after consistency the full length resizing is the way to go. If you want to not bump the neck back as far, then the redding shell holders are for that.

February 13, 2018, 05:05 PM	#8
HiBC Senior Member Join Date: November 13, 2006 Posts: 8,283	I suggest you not try to incorporate every side trail of information you find into your loading practice. I take "partial sizing" as an attempt to neck size only with a full length size die. Its not a good practice.The case body gets sized for diameter anyway. Squeeze a banana in your hand,it gets longer. You don't want to skip the part where the die restores the shoulder. It might be that setting the die to hard contact the shellholder gives you excess head clearance.Its fine to use a feeler gauge between shellholder and die for a consistent setup. IMO,a dime is too much.It leaves the shoulder uncontrolled. Long seating bullets MIGHT be a plan if you are fireforming Ackley improved's or something. I suggest you not introduce a new variable with your seating depth. Try to full length size them to .002 head clearance,you have decided on 3.320 seating depth,use it. Just load them and shoot them. Nothing kinky required. You might paper clip sort them after. Consistency.

February 13, 2018, 05:12 PM	#9
OzeanJaeger Senior Member Join Date: September 8, 2014 Posts: 301	IMHO if the rounds were loaded within the tables (or more) the pressure garadient between start load and max is always going to be limited by the chamber walls. The brass will snap and snap back uniformly for all intensive purposes. Sort of like water is not compressible until the pressure is truely astronomical. So too with brass. Surely there will be some difference, but it’s so small so as to be immeasurable without a physics lab. IMO this will effect nothing. I run ladders all the time, and consider those “fired”, and ready for match loading like all the rest.

February 15, 2018, 06:25 AM	#10
std7mag Senior Member Join Date: June 23, 2013 Location: Central Taxylvania.. Posts: 3,609	Steve, Your way over thinking this. Get a Lee neck sizing die and be done with it. Make sure you segregate your casings per rifle though. (Savage, 1903, etc)