I think the significance of most issues like this are overblown. There's two different scenarios here that no one seems to differentiate. With short cartridges like the .45ACP in proper .45ACP chambers, the bullet is traveling through and is guided by the throat. Same for firing .38's in .357's and .44Spl's in .44Mag's. The bullet enters the throat before it clears the case. With a short cartridge in a very long chamber, where the bullet has enough room to clear the case before it enters the throat, it 'can' cause a little wobble whereby the bullet might enter the forcing cone something other than straight. Of course, you would probably have to be very scientific about it just to find a measurable difference.