I asked multiple places. For a hunting / field shooting rifle the consensus was 0.004-0.006 clearance. Fired brass from this gun measures 0.315 so I turned so the necks measure 0.3095 with a bullet loaded.
How much is needed?
I went with Lapua 30-06 brass to form my 280AI rounds, during sizing the necks thickened.
Reamer print shows 0.3156 diameter at the neck so what should I turn the necks to?
I disagree with your assessment on 140's in a 7mag as my pet load has been 140g Partion since the late 80's. I never bothered working up the newer bullets because the 140's plan worked out to 400 or so.
I also started shooting Nosler factory loaded 140 AB's in my 280AI and enjoyed great...
150ABLR is treating my son well. As soon as I got this load developed he took my rifle from me...
Fast spot light shooting from 100-150 yards
Laying prone at 400
Rifle came to me with bullet stuck 1/2 way down the barrel. Rifle will close easily on a no-go chamber gauge. This excessive head space can lead to lite primer strikes for sure.
But can a lite primer strike cause incomplete ignition thus causing the squib?
If I give up on the ABLR I will go to 200 AB. I know my gun will shoots Bergers because it will stack the HSM 210 VLD factory loads in a ragged hole. I prefer the Accubond bullet though