Everything comes to play when considering oal, everything. Most importantly, neck tension.
I threw setback into the mix because you shouldn't be scared to deviate from suggested oal, IF you follow one simple seating rule.
Seat bullet ogive, that's the curvature coming off straight wall bearing surface. Keep ogive 1/32" off case mouth.
For those who are scared of increased pressure, you're right. Deeper you seat, higher the pressure. As to setback blowing up guns, myth. Factors like insufficient neck tension, unsupported chambers, wrong powder and powder overcharges are what blow up guns.
Setback is a product of lost neck tension. Inertial sling is what becomes of setback. So be careful, leave chamber room.
Your primary concern is neck tension, secondary is feed ability and third is accuracy. Seat your pistol bullet for optimal feed ability, published oal is pertinent to weapon used for published data.
Regards,
dc.
P.S. Forgot the put the pudding into the post. Industry doesn't setback as overriding event in catastrophic case failure, cartridge related handgun failure. It's either been dismissed or viewed as a secondary or even third factor in case related failures.
One quick call to Sierra or Hodgdons will lend perspective.