Fire forming and full length sizing

[jaytee]

Earlier I posted about chamber length vs. case length on my 220 swift and received some good feedback. I believe it was in this thread that a few folks suggested fire forming my brass and that it might take 2 or 3 maybe more firings to get the brass to the final shape of the chamber. My question though is if I full length size, which is what I've always done, after every firing how am I not just spinning my wheels in trying to get the brass to fire form to the chamber dimensions? Doesn't the sizing negate the fire forming? I apologize if this is a stupid question. Thanks for helping a rookie out.

 

[6BRA]

you can use a full length die without bumping shoulders. Back it off the shellholder.

 

[SKWERLZ]

You can normally feel if the die is bumping the shoulders Or not, it will be a different feel at the end of the stroke.

Set it so it’s definitely sizing the body as that’s the part that if neglected can be difficult to fix.

 

[Uncle Ed]

 

[K22]

It's not a stupid question. I'll offer my method based on my experience using a full-length sizing die for the issue you asked about assuming you don't have a neck sizing die. If you have a neck sizing die, you can use that until you encounter resistance chambering a case. I personally don't like that approach but there is nothing technically wrong with it that I'm aware of.

Measure the fired case headspace of several case, about 3 to 5 with the spent primer removed.

Turn the FL sizing die down until it touches the shell holder, zero cam over. Lube and size the case then measure the sized case head space. If the shoulder set back is no more than .001" or less and not greater than the fired case head space, check in the rifle preferable with the firing pin assembly removed to access for optimum chambering, i.e., only slight resistance encountered.

The goal of this procedure is to produce no more than zero to .001" set back and a sized case that will chamber without significant resistance. However, you don't want to extrude (lengthen) the case from the fired case dimension either. You may have to turn the die down more or back it off to obtain this level of sizing. Go a little at time.

This is the procedure I use but others may have another approach that will work equally well.

 

[6BRA]

body die if necessary

 

[ppaul]

There have been many posts lately regarding this subject and my method is different. If I full length size to just short of the shoulder my case has grown in length to where it will not chamber. I then creep up on the length trying to chamber every time. Doesn't take many tries until the bolt will start to fall into place. When I get to the point where it will close with slight resistance I lock the die ring and I'm done. Of course as the case work hardens I may have to make an adjustment, have to watch for that anyway.

Do others do it this way? Don't mean to hijack the thread.

Paul

As I was typing K22 posted and his method sounds somewhat similar. K22 are we talking about the same method?

 

[darkangel_r2]

As the photo above shows if you start with the die threaded far out it will squeeze the shoulder forward. I think this is the fastest way to lengthen brass. As you thread the die progressively down (more sizing) it will at some point make contact with the shoulder inside the die and will start to decrease the distance to the shoulder relative to a case sized in the same die where the shoulder isn't touched.

Once you find the point where the distance to the shoulder starts to decrease again check that piece of brass in your chamber. If it fits cleanly with no resistance that's the best you can do on that firing cycle. All surfaces at that point are controlled by your die so your brass is as consistent and concentric as it can be made to be. Start the process again on the next firing and it should get longer yet. When a piece of brass can't fit in your chamber you can then start threading the die down until the brass just fits in your chamber and the bolt closes with no resistance. Once you find that point lock that die down as that is the setting you want to use in that rifle.

Factory chambers and neck sizing usually took me 3 shots to get the brass formed well to the chamber. Accuracy was fine and you don't have to clean the brass thoroughly if you use a collet die too so its not that bad if you have components to burn. When done with the FL method above and on minimal headspace barrels that I installed myself it hasn't taken more than two, and two was rare. Usually first shot did it. Accuracy was better as well as sizing methods that don't touch the shoulder and neck at the same time can start the bullet off a little crooked in the throat.

 

[K22]

There have been many posts lately regarding this subject and my method is different. If I full length size to just short of the shoulder my case has grown in length to where it will not chamber. I then creep up on the length trying to chamber every time. Doesn't take many tries until the bolt will start to fall into place. When I get to the point where it will close with slight resistance I lock the die ring and I'm done. Of course as the case work hardens I may have to make an adjustment, have to watch for that anyway.

Do others do it this way? Don't mean to hijack the thread.

Paul

As I was typing K22 posted and his method sounds somewhat similar. K22 are we talking about the same method?

More or less the same principle.

Since I'm primarily a varmint and predator hunter, I want my cartridges to chamber easily. Also, I want to avoid any undue stress on the bolt lugs. As cases age I often evolve into the classical .001 to .002 shoulder bump as necessary.

I set my FL die for a 1/8 turn cam over which is more than is needed. I don't size at this setting. I use Skip Shims under the lock ring of the die to back off the amount of sizing to give me the optimum sizing, i.e.., only as much as needed to produce desire functionality - bolt closure with minimum / slight resistance

As the case ages and if more sizing is needed, I merely replace the Shim with another size shim to increase sizing. This is just a convenience only. Changing the die setting works equally well, it's just more tedious. Some use the Redding Competition Shell Holders to make die sizing adjustments. They all work if applied properly.

I believe an important aspect to making sizing more uniform is to dedicate a group of cases to a specific rifle and rotate their use. In this way, the wear is equalized and it's easier to keep track of case head space changes. I always take a few sample fired and sized case headspace measurements each time I size a lot of case to monitor case head space.

I don't believe this is as complicated as it seems to be judging from the numerous posts on this issue. For years, guys just screw the die down a 1/8 to 1/4 turn cam over per the mfg.'s die instructions and reloaded. There may be some, but I don't know of any head separations that occurred that is directly attributable to using this method. Also, I doubt that the die mfg. would publish something that would create a hazardous situation.

I'm not an advocate of this method because it works the case more than necessary. Also, there is some evidence that optimum sizing aids in improved accuracy according to Redding. Whether that can be realized by the average shooter is another issue. Anyway, for these reasons, a lot of experienced shooters / reloaders reduce the sizing to produce the optimum case fit in the chamber.

 

[ppaul]

K22, thanks for your detailed response. My hope in posting my method is to avoid all this 2, 3 times fired method and then have it still be a guess on if your there yet. Also this method needs no comparators or other precision measuring tools. I do own and use them all though as it is helpful to monitor and compare case size and condition.

More or less the same principle.

Since I'm primarily a varmint and predator hunter, I want my cartridges to chamber easily. Also, I want to avoid any undue stress on the bolt lugs. As cases age I often evolve into the classical .001 to .002 shoulder bump as necessary.

I set my FL die for a 1/8 turn cam over which is more than is needed. I don't size at this setting. I use Skip Shims under the lock ring of the die to back off the amount of sizing to give me the optimum sizing, i.e.., only as much as needed to produce desire functionality - bolt closure with minimum / slight resistance

As the case ages and if more sizing is needed, I merely replace the Shim with another size shim to increase sizing. This is just a convenience only. Changing the die setting works equally well, it's just more tedious. Some use the Redding Competition Shell Holders to make die sizing adjustments. They all work if applied properly.

I believe an important aspect to making sizing more uniform is to dedicate a group of cases to a specific rifle and rotate their use. In this way, the wear is equalized and it's easier to keep track of case head space changes. I always take a few sample fired and sized case headspace measurements each time I size a lot of case to monitor case head space.

I don't believe this is as complicated as it seems to be judging from the numerous posts on this issue. For years, guys just screw the die down a 1/8 to 1/4 turn cam over per the mfg.'s die instructions and reloaded. There may be some, but I don't know of any head separations that occurred that is directly attributable to using this method. Also, I doubt that the die mfg. would publish something that would create a hazardous situation.

I'm not an advocate of this method because it works the case more than necessary. Also, there is some evidence that optimum sizing aids in improved accuracy according to Redding. Whether that can be realized by the average shooter is another issue. Anyway, for these reasons, a lot of experienced shooters / reloaders reduce the sizing to produce the optimum case fit in the chamber.

 

[6BRA]

On a full length die, even if backed off the shell holder, you will be doing more than just the neck. Although not all the way to the base. If you want to full resize with out touching neck or shoulders, use a body die. They are cheap medicine.

 

[Ned Ludd]

I size virgin brass with a bushing die solely as the first step in achieving the neck tension (interference fit) I want. If the die is set properly for fire-formed brass, it will not move the shoulder of virgin brass at all. In other words, it's similar in terms of results to using a neck-sizing die only.

In my hands, the shoulders of virgin Lapua .308 Win brass move about .004" to .006" on the first firing. For .223 Rem Lapua brass, the shoulder movement on the first firing is even greater at about .006" to .008". Because I only bump the shoulder back about .0015" to .002", fire-formed brass is much closer in size to the dimensions of fire-formed brass than it is to virgin brass. So even though you are squeezing the case down as you re-size it, you are only squeezing down it just barely enough such that it chambers easily on subsequent firings. Thus, you are not completely "undoing" the fire-forming process with virgin brass simply by resizing it.

 

[6BRA]

On a full length die, even if backed off the shell holder, you will be doing more than just the neck.

 

[Vinootz]

I know this is an old thread so please excuse me. When the case grows in length after running through the die, do I just run it through the die again with the same setting ? Or do I turn in the die a bit and then run it.
I start out with feel method without firing pin and turning out die a bit until bolt drops. The other thing is if the case chambers it hasn’t fully grown enough to be bumped. Am I missing anything. I measure before and after with comparator. I assume the objective is to find out what the final measurement is that the case will grow? Should I be looking at this differently. I’m not a very experienced reloader. But I’m going to be. Especially with some good advice from you folks; if you’ll indulge me.

 

[Vinootz]

I know this is an old thread so please excuse me. When the case grows in length after running through the die, do I just run it through the die again with the same setting ? Or do I turn in the die a bit and then run it?
I start out with feel method without firing pin and turning out die a bit , turning in die until bolt drops(as mentioned above). The other thing is if the case chambers it hasn’t fully grown enough to be bumped? Am I missing anything? I measure before and after with comparator. I assume the objective is to find out what the final measurement is that the case will grow? Should I be looking at this differently? I’m not a very experienced reloader. It’s hard to make the time I’m so busy. But I’m going to be. Especially with some good advice from you folks; if you’ll indulge me. Thanks

 

[Coyotefurharvester]

If it is fired brass and you are sizing to reload (and the fired unsized, deprimed brass will chamber correctly) I will set the die in toward the shell holder a 1/16 of a turn and size a different case. Continue making die adjustments until the brass doesn't "grow" (lengthen). If new brass I first measure the length of a case, partially seat a spent primer(leave it 0.009-0.010 proud) than chamber the brass and measure overall length. You now have your bolt face to case base clearance (headspace). If it is new brass and my spent primer results in a 0.003+ headspace (typically new brass is well short of chamber dimensions) its ok if the die setting pushes the shoulder out a thou or 2. The end goal 1. every case(and finished round) must fit the chamber properly (for function of firearm) and 2. performance (accuracy)and safety (safe to fire) requirements are met when cartridge is finished.

 

[Vinootz]

If it is fired brass and you are sizing to reload (and the fired unsized, deprimed brass will chamber correctly) I will set the die in toward the shell holder a 1/16 of a turn and size a different case. Continue making die adjustments until the brass doesn't "grow" (lengthen). If new brass I first measure the length of a case, partially seat a spent primer(leave it 0.009-0.010 proud) than chamber the brass and measure overall length. You now have your bolt face to case base clearance (headspace). If it is new brass and my spent primer results in a 0.003+ headspace (typically new brass is well short of chamber dimensions) its ok if the die setting pushes the shoulder out a thou or 2. The end goal 1. every case(and finished round) must fit the chamber properly (for function of firearm) and 2. performance (accuracy)and safety (safe to fire) requirements are met when cartridge is finished.

Great - thank you !