The reamer and SAAMI spec drawings for the .284 Winchester indicate a .320 neck OD. The FL Redding resizing die is a .309 and the loaded Lapua brass reflects .3125 OD Many of the .284 match reamers cut with a .316 to .318 neck diameter. My reamer is ground to cut a .3165 neck and I have had flier issues with lighter/shorter hunting bullets. I am curious to what neck diameters others are using in their .284 Winchesters chambers. The reason for the .320 neck was so the .284 did not over pressure the Winchester model 88, 100 and older Savage model 99 rifles. I have not head any pressure issues with the .284 in a bolt gun.
Nat Lambeth
Nat Lambeth