I've been reloading bottleneck cases for over 25 years without a problem, but my first go at straightwall cases has got me stumped. Every time I try seating a projectile the cases just crush down and the bullet only goes in about 1mm. I'm using a Redding 3 die set as per the instructions. Projectiles are Remington 300gn sjhp. Does anyone know what I might be doing wrong?

Are you belling the case mouth?

Yes, I've screwed the expander plug almost all the way down. I'll try posting pics of cases.

I have a feeling your sizer die may be closing that mouth too much or the bullets are oversized.

Never see that with straightwalled.

Measured the various bits. The bullets are .457, the body of the expander plug is .456 and the flare at the top of the expander is .461

You aren`t crimping while seating the bullet are you?

Yep! thats exactly what I was doing! I usually lift the ram and then lower the bullet seater until it touches the bullet and then start adjusting from there. Now I realise this was crimping the cases! Have loaded a few now and its working fine, thanks.

I found another way to crumple straight wall cases. Same as you, new to straight rifle cases. New dies, weird third die included.
Used FLS die supplied, "where's my bloody expander plug"? I thinks.

Somewhere gets the idea the third die is a belling thingo, so used it to only just start to enter the neck.
So on seating a bullet, all sorts of wrinkles appear.
This was because the first part of the bell die WAS the neck expander, and the bell part was way up the top somewhere.

quote:

Originally posted by jdl45:
I've been reloading bottleneck cases for over 25 years without a problem, but my first go at straightwall cases has got me stumped. Every time I try seating a projectile the cases just crush down and the bullet only goes in about 1mm. I'm using a Redding 3 die set as per the instructions. Projectiles are Remington 300gn sjhp. Does anyone know what I might be doing wrong?

Bell the case mouths enough that you can insert the bullet into the case past the mouth edge by hand before you slip it into the shellholder and seat the bullet all the way.

(Your bullet bases are catching on the case mouth rims and causing them to collapse as you try to seat them. You must get the bullet bases into the case mouth past the point where they can catch on the edge of the case mouth BEFORE you push them up into the seating die to finish the seating job.)

Judging from your pictures:

1) Put a larger bell on the case mouth.
2) Do not seat and crimp in the same operation. First seat the bullet, then crimp it.

seperate the crimping stage to the last thing you do.Don't combine it with seating the bullet.Use a lee fac crimp die!Best fac crimp die for the 45-70 IMO!

If you put a slight champher on the inside of the case mouth you will not have to bell as much.
Doing the crimping seperately is good advise.
Good Luck!

quote:

Originally posted by ricciardelli:
Judging from your pictures:

1) Put a larger bell on the case mouth.
2) Do not seat and crimp in the same operation. First seat the bullet, then crimp it.

Crimp dies were designed to operate while seating the bullet. It is quite simple and logical.

Any half-wit can do it with a little bit of finess. One way is to put an empty case in the shell holder and screw in the die until it just starts to crimp. Not hard?

Then wind the die back up a fraction.
With another case ready to go primer,powder etc.
start seating a bullet. Keep winding the bullet seater down. When it's within a whisker,
wind the die body back down again.
Some more very minor adjustments for perfection
and it's done. Any half-wit can do it.

Of course, if your cases are all the same length it's a big help.