Resizing issue

[dbldown]

Last night I was FL resizing some 243 brass I took in trade. Before resizing I measured the length then again after resizing. Every cartridge stretched significantly. Example: 2.045 before (max) to 2.059 after resizing.
Granted I am new at reloading but this seemed excessive.
I am using rcbs rc, lee FL die.

Once fired then I can neck size but I have over 300 brass to go through.

I am thinking my die is set wrong.

 

[243winxb]

Brass gets longer after full length sizing. Trim to lenght after sizing. Make sure the sized brass will chamber before loading.

 

[ants]

That's normal, dude. Totally normal.

Now you gotta trim it down to 'trim to' length.

Generally trim about 0.010" less than SAAMI max length.


(psst, dbldown. Got any books on reloading? They explain that.
Or go to the powder manufacturers' web sites.
Most of them have tutorial on reloading procedures.
Good luck, friend.)

 

[Walkalong]

When fired, brass expands to fill the chamber, shortening it, but when we resize it, we squeeze the diameter back down, lengthening it. It is quite normal for rifle brass to be longer after sizing. Always size before measuring and trimming.

 

[fguffey]

There was a time I ask "It it stretch or flow, or is it stretch and flow, or is it the same, stretch is flow??

Nothing! As to your findings by measuring before and after, I am going to assume you are talking about case length, that would be from the case head to the mouth of the case, if so that is what I would expect. When the case is fired (depending on the rifle) the case fills the chamber, most shooters have fast ammo meaning the case, bullet powder and primer accelerates to a speed that allows it to get to the front of the chamber before the primer is crushes by the firing pin, not my ammo, my firing pin crushed the primer before the bullet, case and powder knows their little buddy the primer has been hit.

By what ever method the case when fired fills the chamber, by what ever method the shoulder forms to the shoulder of the chamber, the case body fills the space provided for it in the chamber body and the neck expands, and, the head of the case moves back to the bolt face, every event described contributes to the case stretch two ways if allowed, out against the chamber walls and out as in forward.

Then comes full length sizing to minimum length, the body of the fired case diameter is reduced, when the body is reduced in diameter the shoulder moves forward and takes on the appearance of a radius, when the shoulder is pushed forward the neck also moves forward (case gets longer from the head of the case to the mouth of the case), at this point the neck gets sized, it does not get thicker or thinner, it gets longer or shorter, when the neck is sized down the neck gets longer, when the neck is expanded the neck gets shorter, so when full length sizing expect the case to get longer.

Back to my assumption, the case getting longer when sized is a given, my purpose for measuring a sized case is to determine the length of the case from the head of the case to it shoulder, meaning if I am full length sizing cases to minimum length the length of the case will shorten from the head of the case to it's shoulder. I determine the length of the chamber before sizing and my favorite case is one that will not chamber because it is too long from the head of the case to it's shoulder, and that is what I do, I size cases to the chamber, others fire first and call themselves 'fire formers' when I fire a case I get once fired cases,

Difference? others fire to determine the effect the chamber will have on a case when fired, I measure the chamber first to determine the effect the chamber WILL have on a case when fired. After firing is a good time to gain information about the effect the chamber has on fired cases, I am not a fan of making the same mistake over and over and over, fire it once, then measure, firing THAT ONE CASE 5 times leads the reloader into the twilight zone, they think the case is becoming an adult case and is not full grown until it is fired 5 times +, fire it once, make your measurements, and if able and have access to the companion tool to the press, the feeler gage, make adjustments.

Learn to use the FL sizer die before you allow someone to talk you into getting a 'not necessary but nice to have die.

F. Guffey

 

[fguffey]

"Once fired then I can neck size but I have over 300 brass to go through.

I am thinking my die is set wrong"

No, I recommend practice, lots of practice, with practice there are two kinds, there is practice and then there is correct practice, you can practice it wrong over and over and get it wrong every time, on the other hand if you practice it correctly you get it correctly, ever time.



I would not suggest you size all the cases then start loading, full length sizing is not always necessary, my opinion it is better to determine the length of the chamber first, others fire the cases to determine the effect the chamber's effect on the case when fired, again, I have one chamber that is .016 thousands longer than a minimum length case or .011 thousands longer than a go-gage length chamber/

The perfect chamber? The go-gage length chamber according to someone called Sammy has a + or minus after it, not my chambers, not my cases, I determine the length of the chamber before firing, what does that do for? It gives me control of the window, I( am a fan of the 'narrow window) correct practice makes perfect, practice it wrong, get it wrong every time.

F. Guffey

 

[bigedp51]

dbldown

When you full length resize a cartridge case it "will" get longer.

It gets longer because you squeeze the case to minimum SAAMI case dimensions, and it "grows as you compress the case.

It gets even longer if the inside of the case neck isn't lubricated.

Old cigarette commercial below from the 1970s when the long 100mm cigarettes came out but it applies here to your resizing.

"It's not how long you make it, it's how you make it long"

I quit smoking and got bigger and thats normal also.

I now use the money saved from not smoking to find out "how you make it long"




I don't buy someone else's fired cases because you don't know "how" he made them "long" and how much the cases stretched in the web area.




Get a Lee Collet die and neck size your cases, they won't get longer, you don't need to lube the cases and they will be more accurate.



Click on the link below and watch the video.

http://www.youtube.com/watch?feature=player_detailpage&v=RZEas38vkKg

AND read the front section of the reloading manuals, this problem is explained in depth and there is much to learn before grabbing the handle on the reloading press.

 

[dbldown]

Thanks for the replys. I knew the cases were going to stretch but my concern was towards the amount.

 

[ranger335v]

Some streching due to diameter reduction and shoulder set back is normal but 14 thou does seem excessive. Try backing your sizer die up about 1/8th turn (about 9 thou) and try chambering it. If the action closes smoothly leave it there, if not turn it half way back.

 

[243winxb]

Lube the inside of the case neck, less drag/ stretch.

 

[x_wrench]

also, that larger your chamber, the more you will notice this. but dont sit and worry about it. your chamber is your chamber. you can not adjust it.

 

[fguffey]

"also, that larger your chamber, the more you will notice this. but dont sit and worry about it. your chamber is your chamber. you can not adjust it"

There is the Savage, for all others there is the press, the press with the threads, all of my presses have threads, threads make my presses adjustable, all I have to know is the length of my chamber, I adjust the length of the case to off set the chambers effect on the case when fired. Again, I am a fan of cutting down on all that case travel, I form first then fire.

F. Guffey

 

[Sensai]

dbldown, The phenomenon of the magic changing case length has been well described. I recommend that before you full length size all of those cases, you should try to chamber them in your gun. If the fired cases will chamber all you need to do is neck size. It may wind up that you're working the brass for no good reason. If it comes out that you have to full length size, you haven't lost anything by trying.