Water-Man said:
"In my opinion, effectiveness is close enough to be inconsequential."
I'd like to know, factually, what you base that opinion on.
The 327 is far more powerful with better penetration & expansion.
Check the numbers for yourself. It was my opinion, not a declaration of absolution.
A few numbers can be found below. But if you want more, you can look them up for yourself. I'm not going to spoon-feed you, simply because I felt like sharing an
opinion.
Velocity is obviously different, which means energy figures are different as well.
But the end result in ballistics gel and barrier testing is almost exactly the same for nearly all comparable factory SD loads using cup-and-core bullets (copper-jacketed, lead core).
.327 Federal, with AE 100 gr and 115 gr bullets averages 13-15" penetration in gel (with or without FBI protocol fabric in front).
.380 Auto, with the 90 gr Critical Defense load that I carried, averages 13-14" in gel -- with better expansion (again, with or without fabric, as used in the FBI protocol). [Some loads average far less penetration. Some average far more. In the end, the average for the cartridge is roughly the same: 12-16"]
Since I (thankfully) haven't actually shot anyone with either cartridge - let alone enough people for a statistically significant sample size for each cartridge - I have to base my opinion on the information available from ballistic gel testing and personal experience.
I've been shooting .327 Federal for almost 10 years, now, from five different revolvers. And I've been shooting .380s, off and on at times, for 29 years in at least a dozen .380s.
My opinion is that the only difference that matters when up close and personal and using the right ammo, is how much louder and angrier the .327 always is. ...And extra noise for the same result is not what I want.