Ammo checker VS case gauge

[sarge4318]

...Cases with a tight in/out bend at the shoulder like 303 tend to work-harden there in manufacture, and if the chamber is reamed deep - as it often is - the case stretches at the web in fire-forming rather than rolling the shoulder forward. Even neck-sizing only can't remove the risk of separation in that situation.
..

I think a big part of the issues with a .303 is the case headspaces off the rim and with generous chambers the brass gets very thin near the head on only a few firings.

I have had separations with S&B brass 100% of the times I have reloaded them (on ever first reload). Admittedly I have stopped using them so might find one that lasts for a second shot and I don't anneal if that makes any difference to them.
However, I have reloaded the PPU brass 3 times and so far no separations. With several .303s to load for I full-length size each time, not just neck sizing, so giving them a good workout.

[Fox Tales]

I think a big part of the issues with a .303 is the case headspaces off the rim and with generous chambers the brass gets very thin near the head on only a few firings.

I have had separations with S&B brass 100% of the times I have reloaded them (on ever first reload). Admittedly I have stopped using them so might find one that lasts for a second shot and I don't anneal if that makes any difference to them.
However, I have reloaded the PPU brass 3 times and so far no separations. With several .303s to load for I full-length size each time, not just neck sizing, so giving them a good workout.

I'm going to guess you answered your own question with " generous chamber " dimensions.
I doubt annealing will help as this only affects the neck and shoulder .
As someone who has no experience of the 303 , can the die be adjusted for minimal shoulder set back , as per non Rimmed cases ?

[sarge4318]

I'm going to guess you answered your own question with " generous chamber " dimensions.
I doubt annealing will help as this only affects the neck and shoulder .
As someone who has no experience of the 303 , can the die be adjusted for minimal shoulder set back , as per non Rimmed cases ?

Actually I was adding to MikB's comment, not asking a question.

I think you're right in that annealing won't affect it. S&B brass is notorious for this, the LERA boys I spoke to all seem to know the S&B brass is a one use case.

To answer your question the die can be adjusted as you say, and if you only have one rifle (therefore chamber) to load for you can neck size and hardly touch the rest of the case minimising the stretch. But I have plenty of PPU once-fired and that seems to last well giving 3 firings so far on the ones I've reloaded, however the PPU ammo is pretty good too, and relatively cheap and available so my the need to reload 303 is not as great as some of the other cartridges I shoot.

[MikB]

I'm going to guess you answered your own question with " generous chamber " dimensions.
I doubt annealing will help as this only affects the neck and shoulder .
As someone who has no experience of the 303 , can the die be adjusted for minimal shoulder set back , as per non Rimmed cases ?

I had a theory that annealing new case shoulders might help, because what prevents the shoulder rolling forward in fireforming is the fact that it's so short and the in and out bends are very close together, work-hardening the whole area. If you could anneal the local area before fireforming in the "generous chamber", you might avoid stretching the web and produce a case that would last several reloads with neck-sizing. I never really tested this properly, though.

The *proper* way to set a standard die up for neck-sizing would probably be to make up a spacing washer to sit on top of the shellholder, or try to add some spacing buttons to the bottom face of the die. Anyway, I just hoped the die setting and the ram stroke would take care of it.

But as sarge4318 says, with S&B brass nothing seemed to really work, and I had to learn the LERA lesson the hard way. Separation as it happened was never dangerous on the range, but obviously needed a moment's work to get the decapitated case body out.

[Fox Tales]

I had a theory that annealing new case shoulders might help, because what prevents the shoulder rolling forward in fireforming is the fact that it's so short and the in and out bends are very close together, work-hardening the whole area. If you could anneal the local area before fireforming in the "generous chamber", you might avoid stretching the web and produce a case that would last several reloads with neck-sizing. I never really tested this properly, though.

The *proper* way to set a standard die up for neck-sizing would probably be to make up a spacing washer to sit on top of the shellholder, or try to add some spacing buttons to the bottom face of the die. Anyway, I just hoped the die setting and the ram stroke would take care of it.

But as sarge4318 says, with S&B brass nothing seemed to really work, and I had to learn the LERA lesson the hard way. Separation as it happened was never dangerous on the range, but obviously needed a moment's work to get the decapitated case body out.

Personally, I'm a fan of Redding competition shellholders. I know not everybody likes them but they work for me . I appreciate that they are not cheap. Each set contains 5 shellholders from +0.002" to +0.010" , remember that there is an industry standard for the standard shellholders . They allow you to maintain hard contact with the die , enabling consistent sizing . Start with the +0.010 and work through them until you achieve the required shoulder bump . What could be simpler.