New Win. 243 brass won't hold bullet

[vonb]

I have some brand new .243 Winchester brass that is brand new that was purchased 6-7 years ago. The other night, I went to load some rounds and ran into an issue. As always, my first step is to run them through a Forster F/L sizer,with expanding ball in place) using Imperial wax. I mainly do this to round out the case mouth.

After performing the step above, I went to charge and seat and the seating was where I ran into an issue. I was seating 100gr Remington Core-Lokts and after seating, I noticed that the case mouth was too large to reliably hold the bullet in place. Therefore, just shaking the case would move the bullet. Where have I gone wrong here?

I have performed these same steps many times in the past and no changes have been made to my die. This setup has worked well using 85gr HPBTs and 87gr VMAX. I'm using a Forster Co-Ax press.

 

[Dubya]

Be sure to clean the wax out of the necks and if you are using
to much powder you may have a compressed load situation, which could cause the bullet to unseat itself.

Gary.

 

[vonb]

I didn't use any wax in the necks and I don't think 35.5gr of IMR4064 is compressed.

 

[Spotcheck_Billy]

Is this Forster F/L die and expander ball new or have you used it successfully in the past?

 

[terryb]

Had this happen to me twice using an old set of Bonanza,forster)fl dies and win. brass in a .308.Worked fine with R-P or Fed.What's happening,when you run the new brass in your die the expander takes it out a bit oversize,and the die neck is not touching the brass enough to size it back down to hold a bullet.The .243/308 win. brass is a bit thinner in the neck than r-p or fed,Forster will probably send you a new die if you send them the old die and a couple of brass you ran in the die.

 

[Preacher]

If you have used this die before, then your on your own.
If it's a new one, you might need to shave the expander ball down a little as it sounds like it's to big...

 

[vonb]

This is a die that I have used in the past successfully with Winchester brass...That's why I'm stumped myself.

 

[BoydAllen]

Run a few cases through the die without the expander ball. If there is enough neck tension, then you will need a smaller expander ball, at least until this lot work hardens from use. What may be happening is that this batch of brass may be annealed to a softer,less springy, condition in the necks.

 

[billmo]

Hunt127588, I ran into this same thing with Win. brass for a .308 a few years back. I was using a regular Redding neck sizing die. A shooting buddy of mine uses RCBS FL dies backed of from the shell holder a bit. I gave the brass to him and he was able to use it. I guess the brass was at the thin side of spec and maybe my die was at the more open spec. I never had that problem with Lapua, Fed, or R-P brass. Just an observation. Bill

 

[vonb]

Thanks everyone for the replies. I'm going to do a little experimenting going forward and see what gives. Should the brass not work in my .243, I may just neck up and use it in my .260 even though I'm not a huge fan of differing headstamps.

 

[Dubya]

Have you measured the ID.,inside diameter) of the neck on your brass after it's been through the sizing die? Most .243s' will measure .239 to no more than .241. .239/.240 is norm.

Just trying to help,
Gary.