Re: 280 Ackley Hart barrel .313\" neck
[ QUOTE ]
Is some space around the neck necessary?
[/ QUOTE ]
Absolutely, the brass needs to be able to expand to "let the bullet go". I like .003-.005 total in my hunting rifle just to be safe, don't want to run into problems with dirt, dust, or moisture in the chamber preventing the brass from expanding, that could get ugly quick.
If your once fired brass measures .311 your neck is probably close to the .313 advertised as brass spings back a bit after being fired and cooling down. So all you should need to do is just clean the necks up .001 or .002 and you should be good to go.
Ignorance can be treated with education, sadly there is no cure for stupidity.