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Reloading Techniques For Reloading


full length resizing

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Old 02-07-2014, 06:07 PM
Platinum Member
Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,262
Re: full length resizing

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.
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Old 02-07-2014, 10:39 PM
Junior Member
Join Date: Nov 2013
Location: Grande Prairie Alberta Canada
Posts: 8
Re: full length resizing

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
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Old 02-08-2014, 06:41 AM
Platinum Member
Join Date: Dec 2005
Location: Tucson Az
Posts: 1,267
Re: full length resizing


"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."


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.


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.


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.
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Old 02-08-2014, 10:39 AM
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Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,262
Re: full length resizing

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.
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Old 02-08-2014, 06:08 PM
Silver Member
Join Date: May 2008
Location: Ohio
Posts: 248
Re: full length resizing

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.”
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Old 02-08-2014, 06:54 PM
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Join Date: Aug 2003
Location: NC, oceanfront
Posts: 3,262
Re: full length resizing

Good point, and good information.
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Old 02-08-2014, 09:45 PM
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Join Date: Dec 2011
Location: S.E. Michigan
Posts: 3,464
Re: full length resizing

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.
'It's not about me, it's about we'..........
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