Originally Posted by
Valorius
The problem with .380 is that rounds that expand rarely penetrate deeply enough to satisfy most defensive minded people. As in often not even 10".
The one .380 round that really seems to perform extremely well in both penetration and expansion is Buffalo Barnes .380+P solid copper hollowpoint ammo. You don't say what kind of gun you have, so i don't know what the barrel length is, but even in short barreled Ruger LCP type guns the Buffalo Barnes load hits over 1100fps velocity, and should get 11+" penetration to go with .60-65 caliber expansion.
This round actually exceeds the gel performance of the legendary Illinois State Police Federal 9BP 9mm+P+ 115gr JHP loading, which usually gets about 10" penetration and .55" caliber expansion in gel. A round which is in the 1300fps/450fpe range.
From all the tests i've seen, magtech rounds perform very poorly in expansion. So do the winchester PDX .380 rounds that seem to be very popular. Hornady Critical Defense rounds seem to expand, but they are unbonded and low powered, so they will perform very poorly in barriers in comparison to the Buffalo Barnes round.
Underwood ammo also makes some very hot .380+P ammo with the Speer Gold Dot bullet, that is a lot cheaper than the Buffalo Bore ammo i just recommended. Also, because it's bonded core and has much higher energy, it should perform much better in barriers than any standard pressure .380 ammo.
If you want to stay with standard pressure ammo, the one round that always seems to do well in tests in that it gets both good penetration and decent expansion is the Federal Hydrashok.