Neck Expander die/RCBS .309 ?

[Willyp]

How much do you flair the case neck when running this into the case? Then,how do you un-flair it?

[GBertolet]

I have the exact same die. You adjust the neck expander down to flare the case, just enough to be able to start the bullet without shaving lead. You unflair it by the bullet seater die. This all happens during the bullet seating operation. You adjust the die body down until you just remove the flair, or further if you want a crimp. That's it.

[MT Chambers]

I must be missing something here as most .309 sized dies will be for cals. with a shoulder and the dies will expand the neck to whatever size the button is but these 2 die sets will not flare. The 3 die sets for straight wall cases have provision for expanding and BELLING or FLARING . I'm not sure about getting Lyman M-type expanders for your dies or you may need a Lee universal expander(flaring tool), then even the smallest amount of crimping on your loaded round will removed any flare.

[Outpost75]

The RCBS cast bullet expanders have a cylindrical section with 15 degree flared shoulder threaded onto an adjustable rod which can be set to flare or not. You can get different plugs for various diameters to interchange on the same die body. I prefer it to the LymanM--die.

[Motor]

MT Chambers, Standard bottleneck rifle 2 die sets do not have a feature that will bellmouth the case neck. These calibers are most often loaded with jacketed bullets that do not require a mouth flair.

Straight wall pistol dies do have a mouth flair. Pistol bullets tend to be very flat base and can be very hard to start without a mouth flair plus non jacketed bullets are very common for pistol reloading.

Outpost75, I like my RCBS neck expander/flair tool too but have to say you are the 1st guy I ever seen to say he likes it better than the M-die.

A friend is putting together a M-die for me to use for my cast 54R loads. He insisted I try it. Said I'd never go back. I'll still use the RCBS for my 30-30 though.