Bullet seating issue

[KeltecFan]

If the FL sizing die is properly adjusted and the correct diameter expanding button used then the correct amount of neck tension should be realized. A hardened neck may not be as elastic as a softer one but it should still be tight enough not to let a bullet drop into the case. The only time I have experienced loose neck tension was when using a FL die to neck size some 35 Remington cases. I note that the RCBS die set has an expander die. Is this set up to over expand the case mouth?

I wondered about that too. However, you'd REALLY have to have the expander go deep into the case to have it make the projectile drop through. However, I have never loaded .458. I've loaded .460 for a revolver and .45-70 but not .458.

Here's the SAAMI drawing for .458 Win Mag.

 

[fingers284]

Slow down a bit boys , your giving the OP some inappropriate advise for his problem....458, a straight walled case with 3 die set...the 'expander isn't on the primer rod, it's in a separate die that has the "expander/case mouth flare in it.

Two things can be causing the OP's malady, the first is improper use of the expander die...highly unlikely as it take an enormous amount of force on the press to do it and a distinct "bulge" in the case barrel is evident and the OP doesn't mention anything like that.

The second thing is quit possibly the wrong expander ball was screwed to the die at the factory. The OP stated that he measured the bullet & the expander ball saying they are the right ones but no actual measurements were given. I don't know his reloading history or experience so will go out on a limb here and suggest he found they measured the same so assumed that that was "right". If that is the case then you do have the wrong expander. RCBS has 3 different sized expander balls for the .458 bullet. The proper one shipped with .458 Win Mag dies has a dia of .4555 to .456 so the have a 2 thou grip on a jacketed factory bullet...however the other expanders they offer are .458 and.460 for their Cowboy Die sets (for loading cast boolits in 45-70's mostly). If your expander die was meant for one of these sets and measures the .458 or .460 then your jacketed bullets will be somewhat loose.

 

[jethunter]

Slow down a bit boys , your giving the OP some inappropriate advise for his problem....458, a straight walled case with 3 die set...the 'expander isn't on the primer rod, it's in a separate die that has the "expander/case mouth flare in it.

Two things can be causing the OP's malady, the first is improper use of the expander die...highly unlikely as it take an enormous amount of force on the press to do it and a distinct "bulge" in the case barrel is evident and the OP doesn't mention anything like that.

The second thing is quit possibly the wrong expander ball was screwed to the die at the factory. The OP stated that he measured the bullet & the expander ball saying they are the right ones but no actual measurements were given. I don't know his reloading history or experience so will go out on a limb here and suggest he found they measured the same so assumed that that was "right". If that is the case then you do have the wrong expander. RCBS has 3 different sized expander balls for the .458 bullet. The proper one shipped with .458 Win Mag dies has a dia of .4555 to .456 so the have a 2 thou grip on a jacketed factory bullet...however the other expanders they offer are .458 and.460 for their Cowboy Die sets (for loading cast boolits in 45-70's mostly). If your expander die was meant for one of these sets and measures the .458 or .460 then your jacketed bullets will be somewhat loose.

This^

And just for fun, measure the bullets and see what diameter they are. Because either your cartridge neck is wide or your bullets are too skinny and you may as well check everything.

A Lee factory crimp would probably fix it.

 

[RMacD]

Slow down a bit boys , your giving the OP some inappropriate advise for his problem....458, a straight walled case with 3 die set...the 'expander isn't on the primer rod, it's in a separate die that has the "expander/case mouth flare in it.

Two things can be causing the OP's malady, the first is improper use of the expander die...highly unlikely as it take an enormous amount of force on the press to do it and a distinct "bulge" in the case barrel is evident and the OP doesn't mention anything like that.

The second thing is quit possibly the wrong expander ball was screwed to the die at the factory. The OP stated that he measured the bullet & the expander ball saying they are the right ones but no actual measurements were given. I don't know his reloading history or experience so will go out on a limb here and suggest he found they measured the same so assumed that that was "right". If that is the case then you do have the wrong expander. RCBS has 3 different sized expander balls for the .458 bullet. The proper one shipped with .458 Win Mag dies has a dia of .4555 to .456 so the have a 2 thou grip on a jacketed factory bullet...however the other expanders they offer are .458 and.460 for their Cowboy Die sets (for loading cast boolits in 45-70's mostly). If your expander die was meant for one of these sets and measures the .458 or .460 then your jacketed bullets will be somewhat loose.

My mistake. I have deleted the wrong information. I was thinking of my own experience and totally neglected to think of the straight walled case. Thanks for the correction.