bigedp51
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- Dec 10, 2010
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When you full length resize the case is squeezed inside the die and the brass can only move upward in the die. Meaning the overall length of the case becomes longer when full length sizing. If sized with a small base die the case will grow in length even more because the case diameter is being reduced more than a standard die.
And when you neck size only you are not squeezing the case body and the case overall length when fired can end up shorter.
Rimmed and belted cases come from a older time when case manufacturing was not as refined as it is today. Meaning the case shoulder location on rimmed and belted cases was not critical.
Below are rimmed .303 British cases, the case on the far left is a new unfired case and the shoulder is approximately 1/4 inch shorter than the chamber. The case in the center is once fired and the case on the right fired three times after being full length resized every time.
As you can see below full length resizing with the die making hard contact with the shell holder these Winchester cases lasted for three reloadings before the case started to separate. On the flip side of this by neck sizing only with medium loads I have gotten 32 reloads before having the case necks start to split.
Below is a fired case in a Wilson case gauge and the amount the case is sticking above the top of the gauge is how far the shoulder will be pushed back when full length resized. My main point being is rimmed and belted cases should headspace off the shoulder and not the rim or belt for longer case life.
The trick with any type cartridge no matter how it headspaces in the chamber is proper fire forming and minimum shoulder bump when sizing. And letting the case headspace on its shoulder with minimum head clearance.
I only neck size my British .303 cases and any other milsurp rifles with generous oversized chambers. This is because the SAAMI dies are smaller than military chambers and overwork the brass.
Chambers and dies vary in diameter and headspace length, and some full length dies can overwork the brass. But as an example on semi-automatic rifles the case diameter should be .003 to .005 smaller in diameter than its fired diameter for reliable extraction. Meaning the type of resizing die used depends on the type shooting you are doing and your preference in dies.
CatShooter and I have different opinions, I prefer full length resizing if possible and CatShooter prefers neck sizing. And CatShooter lubes his cases and I do not because older firearms are made of softer steels and they can not take the increased bolt thrust.
Even though CatShooter and I differ on lubing cases and sizing methods we have remained friends and have not killed each other over reloading methods.
My buddy CatShooter lives in the country, loves shooting ground hogs and putting caster oil and Remington 7 1/2 primer in the cattle feed.
When you full length resize the case is squeezed inside the die and the brass can only move upward in the die. Meaning the overall length of the case becomes longer when full length sizing. If sized with a small base die the case will grow in length even more because the case diameter is being reduced more than a standard die.
And when you neck size only you are not squeezing the case body and the case overall length when fired can end up shorter.
Rimmed and belted cases come from a older time when case manufacturing was not as refined as it is today. Meaning the case shoulder location on rimmed and belted cases was not critical.
Below are rimmed .303 British cases, the case on the far left is a new unfired case and the shoulder is approximately 1/4 inch shorter than the chamber. The case in the center is once fired and the case on the right fired three times after being full length resized every time.
As you can see below full length resizing with the die making hard contact with the shell holder these Winchester cases lasted for three reloadings before the case started to separate. On the flip side of this by neck sizing only with medium loads I have gotten 32 reloads before having the case necks start to split.
Below is a fired case in a Wilson case gauge and the amount the case is sticking above the top of the gauge is how far the shoulder will be pushed back when full length resized. My main point being is rimmed and belted cases should headspace off the shoulder and not the rim or belt for longer case life.
The trick with any type cartridge no matter how it headspaces in the chamber is proper fire forming and minimum shoulder bump when sizing. And letting the case headspace on its shoulder with minimum head clearance.
I only neck size my British .303 cases and any other milsurp rifles with generous oversized chambers. This is because the SAAMI dies are smaller than military chambers and overwork the brass.
Chambers and dies vary in diameter and headspace length, and some full length dies can overwork the brass. But as an example on semi-automatic rifles the case diameter should be .003 to .005 smaller in diameter than its fired diameter for reliable extraction. Meaning the type of resizing die used depends on the type shooting you are doing and your preference in dies.
CatShooter and I have different opinions, I prefer full length resizing if possible and CatShooter prefers neck sizing. And CatShooter lubes his cases and I do not because older firearms are made of softer steels and they can not take the increased bolt thrust.
Even though CatShooter and I differ on lubing cases and sizing methods we have remained friends and have not killed each other over reloading methods.
My buddy CatShooter lives in the country, loves shooting ground hogs and putting caster oil and Remington 7 1/2 primer in the cattle feed.
