I've heard mention of this practice, but never an explanation of how to do it. Is this a safe practice? Is it reliable? I looked through all my die instructions and none have touched on this. I have accumulated a few sets of good used rifle dies that I'd like to use without buying another neck sizing die. For the rifles I currently load, I bought the three set dies when I first got into reloading, so I'm just trying to get good use out of the other die sets. Any help from people who do this?
Neck Sizing with a FL die?
- Thread starter Jbotto
- Start date
Set your FL die up according to instructions. Then, unscrew it about 1/4 turn and set the lock ring.
Before you set the lockring, you might wanna black the shoulder with a marker or something and run the case into the die to make sure you are not contacting the shoulder and defeat the purpose.
Before you set the lockring, you might wanna black the shoulder with a marker or something and run the case into the die to make sure you are not contacting the shoulder and defeat the purpose.
Yes its safe, I do it all the time.
It basically consists of backing the die off & then slowly re tightening it with an indicator for the current position. It works best with bottle neck rifle cases with a body taper.
The correct term is "Partial full length resizing" & what it does is to minimize over working of the brass by matching almost exactly to that particular chamber.
Here's the basics.
Take a fired case from the exact gun you're working with lube it for resizing normally.
Run a candle (or other smoky) flame round the neck & shoulder to give a "smudge" of soot.
Now back off your full length die 1 full turn & lock it.
Run the case up into the die as you would if full length resizing, & pull it back out.
Look closely at the area where the die has scraped the soot off of the neck & shoulder.
Guess how far you need to tighten the die to JUST bring the die down far enough to barely resize to fit.
Tighten the die 1/2 that amount.
Run the case through the cycle again, do not re lube or re smudge.
Repeat the resize, examine, tighten 1/2 as much steps till you JUST get a 360 degree removal of smudge from the shoulder.
STOP & lock the die.
This is the effect you're looking for, see the tiny, but complete ring of contact?
That is the real secret.
If you don't minimally resize the case to JUST clear the chamber when loading it'll be clumsy & stubborn, but by making an absolute minimum reduction in size you get slick easy functioning, really good tailored brass to chamber fit & longer brass life.:
(Images (C) wogpotter 2007)
It basically consists of backing the die off & then slowly re tightening it with an indicator for the current position. It works best with bottle neck rifle cases with a body taper.
The correct term is "Partial full length resizing" & what it does is to minimize over working of the brass by matching almost exactly to that particular chamber.
Here's the basics.
Take a fired case from the exact gun you're working with lube it for resizing normally.
Run a candle (or other smoky) flame round the neck & shoulder to give a "smudge" of soot.
Now back off your full length die 1 full turn & lock it.
Run the case up into the die as you would if full length resizing, & pull it back out.
Look closely at the area where the die has scraped the soot off of the neck & shoulder.
Guess how far you need to tighten the die to JUST bring the die down far enough to barely resize to fit.
Tighten the die 1/2 that amount.
Run the case through the cycle again, do not re lube or re smudge.
Repeat the resize, examine, tighten 1/2 as much steps till you JUST get a 360 degree removal of smudge from the shoulder.
STOP & lock the die.
This is the effect you're looking for, see the tiny, but complete ring of contact?
That is the real secret.
If you don't minimally resize the case to JUST clear the chamber when loading it'll be clumsy & stubborn, but by making an absolute minimum reduction in size you get slick easy functioning, really good tailored brass to chamber fit & longer brass life.:
(Images (C) wogpotter 2007)
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Isn't a safety or reliability issue. It's a trial and error fiddling thing like wogpotter indicates that lets you neck size without buying a neck sizer die. Just unscrewing the die about 1/4 turn guarantees nothing.
If you set up one of your FL dies mark it with something like a Sharpie.
If you set up one of your FL dies mark it with something like a Sharpie.
Since all chambers are different, it would be expected that a quarter would not work for all. That is the reason for fine tuning the die with a marked case.
Easy to do, just takes a little tinkering to get it there.
Important to remember is that there are not many guarantees when dealing with so many variables.
Easy to do, just takes a little tinkering to get it there.
Important to remember is that there are not many guarantees when dealing with so many variables.
If you can do it or not depends on where you pick up your brass, you specific rifles chamber and if you have other rifles of the same caliber.
My 1955 721 in 30-06 has a really tight chamber so I have to full size for it or I have extraction issues. Since I reload so that others can shoot them that dictates full sizeing.
Range Brass...full sizeing is mandatory
I just got in a habit of full sizeing. Yes it works the brass more then need be but I still have four boxes of 30-06 headstamps that predate WWII.
My 1955 721 in 30-06 has a really tight chamber so I have to full size for it or I have extraction issues. Since I reload so that others can shoot them that dictates full sizeing.
Range Brass...full sizeing is mandatory
I just got in a habit of full sizeing. Yes it works the brass more then need be but I still have four boxes of 30-06 headstamps that predate WWII.
I'm a benchrest shooter, I reload only for accuracy. I F/L size only, another way to say it is neck size with a full length sizer. Meaning your only sizing the case to the minimum of .001 headspace. Are you shooting a bolt action? Can your fired case be rechambered without forcing?
I have got 1/2" 5 shot groups at 100 yards with brass sized 3/4 the way down with a FL die.
That is not the best way, but I wait a long time to get a wind so low I can get 1/2" groups. So it is good enough for most things. But for hunting big game, I want the shoulder bumped back. I need clearance for dropping ammo in the mud.
That is not the best way, but I wait a long time to get a wind so low I can get 1/2" groups. So it is good enough for most things. But for hunting big game, I want the shoulder bumped back. I need clearance for dropping ammo in the mud.
Firstly yes, you must be using brass fired in that exact chamber for this to work properly.
Secondly (& rarely mentioned) is the fact that neck-sized cases eventually need full length resizing as they don't spring back 100% to the original size, introducing a variable.
Partial full length resized cases don't have this problem. You can always resize exactly the same as every other time.
Secondly (& rarely mentioned) is the fact that neck-sized cases eventually need full length resizing as they don't spring back 100% to the original size, introducing a variable.
Partial full length resized cases don't have this problem. You can always resize exactly the same as every other time.
It has been my experience the case body contact the die before the shoulder of the case contacts the shoulder of the case. Even if the shoulder of the case does contact the shoulder of the die it could be OK if the reloader understands ‘the degree principle of sizing’. I have used the feeler gage to adjust my die when sizing, I have also measure the height of the die above the press when sizing a case. I have never found it necessary to use Skip’s shims or Redding Competition shell holders but I have one set of Redding Competition shell holders just in case. I paid $5.00 for the #6 set.
F. Guffey
603Country
New member
One thing mentioned earlier that is worthy of restating is that tapered cases take to partial resizing better than cases with less taper. I partial resized for years with my 220 and 270, got great results, and assumed therefore that all cases can be partial resized. I found that was not correct. If you run a case with little taper into the die, you may find that you are squeezing the case at the shoulder and moving the shoulder forward - which isn't what you want to do.
If you chamber a fired case (fired in that rifle) without resistance, then partial resize the case and then find resistance when you chamber it, you are most likely pushing the shoulder forward. If so, try a little less sizing of the case. You don't need to resize the entire neck.
If you chamber a fired case (fired in that rifle) without resistance, then partial resize the case and then find resistance when you chamber it, you are most likely pushing the shoulder forward. If so, try a little less sizing of the case. You don't need to resize the entire neck.
What Mr. Guffey mentioned is the reason the partical technique works best with a tapered case. If the case walls are straight enough that the sides contact the sizing die before the shoulder does, it will actually narrow and lengthen the case between the head and the shoulder, moving the shoulder forward. At that point it can become too long to chamber again until you have pushed the shoulder back. If you were to try the technique with an Ackley Improved chamber, for example, you might be completely out of luck. Or, if you have a rifle chamber that is generous in width, even though it has some taper, the bottom half of the case might start to contact the sizing die and get squeezed narrower and longer before you get very much of the neck sized down.
One countermeasure to keep in mind with long neck cases like the 30-06 is that a lot of bullets only wind up going part way down the neck. Maybe half way for some short bearing surface bullet. In those instances, there is no point in sizing further down than is gripping the bullet.
One countermeasure to keep in mind with long neck cases like the 30-06 is that a lot of bullets only wind up going part way down the neck. Maybe half way for some short bearing surface bullet. In those instances, there is no point in sizing further down than is gripping the bullet.