I know it sounds simple but I'm having a time fireforming some 223 cases. I measure them before and after firing (head to shoulder) and they don't change. I need to lengthen them about .004" to fit my rifle snug on closing.
I've tried partial sizing, neck sizing, always checking each case for center of shoulder to base with a die I made on the lathe.
What do you use for slightly shorter cases.
David

If you had neck sizing bushings you could use a smaller bushing for a tighter fit of the bullet. Are you jamming the bullet into the lands to keep the base of the cartridge hard against the bolt face?
Butch

If you are using a light load you might not be stretchng the brass. You can also neck the neck up and then resize the neck forming a false shoulder at the point you want the shoulder to be.

You are a better man than I am worrying about .004"

Rather than a lengthy bunch of stuff from me check this out ,I think it will help you . Sometimes full loads are required to fill the chamber .

http://www.reloadersnest.com/f...c.asp?TOPIC_ID=13718

http://www.reloadersnest.com/f...ID=12901&whichpage=1

I have a 20 tactical (223 necked down to 20) and it takes a firm charge to get the case to conform to everything in the chamber.

Doc224/375, thanks for the hot links. It is what I was looking for.
butchlambert, I am jamming the bullet into the rifling, it's a 55gr. thinking of the 60 Hornady SX.
ramrod340, The load I'm using is a max load of benchmark.
This all started when I made a die to measure the distance from the head to the center of the shoulder. When I got to measuring my different 223's and 222's I was shocked to find them so different. About .017" from the tightest to the loosest in the 223's. I keep the brass seperate but it got me to wondering, I bought some new brass and was fireforming but they didn't change! Supprised me.
I appreciate the replys guys,
David

quote:

Originally posted by Mark:
I have a 20 tactical (223 necked down to 20) and it takes a firm charge to get the case to conform to everything in the chamber.

I form my Tactical 20 cases out of LC brass and get them pretty snug as they are formed. I'll load them up with my regular PD loads and at the end of the day I have enough fire formed cases to last me.

I'm shooting them in an AR 15 so unfortunately I can't get away with neck sizing those puppies. The riled shoots great but it hates to have one try to slip in that doesn't have its 0.003 or 0.003 shoulder room.

Greg

Actually, what I've done with my fireforming is I made a die that has a steeper shoulder (think a 300 H&H type shoulder, though that is exaggerated) so the case headspaces on the neck/shoulder region. I believe this is better for the cases as it allows for more metal to form the shoulder/body juncture than having it seat there and forcing a smaller amount of metal to move to form the shoulder.

I'll also say that cornmeal has never given me sharp corners, it has always taken firm charges to sharpen them.

As mentioned, if your brass is short seat the bullet out into the lands.

I guess that I haven't had a problem fireforming. For most of my cartridges I have chambered a barrel stub[12-20"] with the same reamer as I have chambered with. I run it in .004 short. I usually use Bullseye to the shoulder and a wax plug. Sometimes with a wildcat I will have to hit it twice.
You don't have to like or care for my method, but it serves my purpose. I probably fireform 2-300 cases of various types a year.
You can't mix your brass in different chambers. Make your measurements right after firing with the spent primer removed. You can remove them without sizing the brass.
Butch

Have had trouble fire forming 22 jet rimless made from .223.The biggest problem is the shallow angle that produces a long shoulder which gets into the thicker brass wall . After three full loads the corduroy shoulder produced by Butch's bushings are still somewhat apparent.( no flame intended Butch ). roger

stronics: If you are doing a bolt gun this is the way to be sure. Expand the necks up to 6mm(.243) and then run the case into the 223 die set so it will size about 7/8th of the neck. At this point try it in the gun, it should not close. Keep turning the die down in 1/4 turns till the bolt will close with a medium amount of force( I don't mean uses a hammer). At this point you have formed a small false shoulder on the neck that will hold the base against the bolt when you firerform. When you fireform the cases they should come out with **0** headspace. I have a Stoneypoint system and uses a headspace insert to measure these cases and uses the measurement if I ever have to reset my FL sizer die. A quick and dirty way to take this measurement is to uses flat feeler gages between the bottom of the die and the top of the shell holder but you always have to keep the same shell holder with the set of dies. I do this with all of my gun. 280Rem up to .308 and then back down -9.3x62 up to .375 and then back down-303 up to 8mm and then back down. After that all I ever do is neck size.