Curt, Your post doesn't include enough information to give a definitive answer, but there's plenty to indicate that some caution is required.
Do you know the type and amount of powder your friend used to load those cartridges? This could make a difference. If he didn't notice that some of the cartridges were noticibly shorter than the others, OR if it didn't bother him, I must question the level of care he used to load them.
Your initial question was, "is there a minimum over all length for the .45 acp with a 230 gr. lead round nose bullet?" Not really, but it's easy to see if the bullet is seated so deeply that the case mouth reaches past the ogive. If it does, the bullet is seated too deeply, and you might very well see some grossly excessive pressures. Also, you're very apt to have trouble with reliable feeding of such short rounds.
The .45 ACP is a low pressure cartridge. SAAMI standard maximum pressure is 21,000 psi, and no published load for the 230 RNL bullet is much above 18,000. Industry standard max overall length is 1.275". Most suggested loads show 1.270 for that shape bullet. A couple of thousandths less is not hazardous, but I'd go no shorter.
Given what the .45 ACP is, there's utterly no logic in trying to "magnumize" the cartridge seeking velocities above 850 fps with a 230. I personally load 230 LRN and plated bullets to about 800 fps. This is plenty to reliably operate any autoloading pistol with a standard recoil spring. It is plenty to knock over steel plates and Pepper Poppers in matches, and reliably runs two different Thompson SMGs. It is also easier on the guns AND the shooter.
I really believe the short, easy answer is to go with Unclenick's suggestion: pull all the bullets, re-expand the case mouths, recharge them with uniform amounts of powder, and reseat the bullets to 1.270", using the cleaned seating die.
If you're comfortable shooting your friend's powder charges, you can probably get away with a shortcut: Use your inertial bullet puller to lengthen all the too-short loaded rounds without actually pulling the bullet out of the case. Then reseat them to the proper, uniform, length.
Good luck to you.
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Blog: Expert Witness