Tribb -
Howdy !
For a magazine-fed application, max allowable c.o.a.l. will be dictated by the limits of clearance inside the magazine. And perhaps sometimes, if a certain cartridge o.a.l. exhibits feeding challenges in the action.
Beyond that, ideally..... you'd like to be able to reach the lands w/ the seated bullet..... or perhaps find the gun shoots best w/ the bullets a couple thousandths off the lands..... or sometimes even might find the gun shoots best w/ bullets seated out for a slight " jam ". Only one c.o.a.l. described above could possibly match the reloading book' spec. So.... I wouldn't let reloading book spec's dictate the c.o.a.l.
It was not immediately clear to me whether your cartridge's o.a.l. could be configured to reach the lands, of even to have the seated bullet reach within a couple 'thou of the lands .... by abandoning the reloading book spec ??
What would be interesting to know is...... what c.o.a.l does get you into the lands territory; and whether that dimension does fit the magazine.... and cycle through the action ?
If your rifle is a single shot, or ( for example ) you are single-feeding a bolt gun; then.... the world's your oyster.
Please let us know what you find out.
With regards,
357Mag