[V19 Experimental Build 7 available!]

So, how much armor penetration does each pellet have? A shotgun slug would punch through armor, but pellets have very little kinetic energy due to their low mass.

Not to nitpick, but shotgun slugs are exceptionally poor at penetrating armor. The slug does have quite a bit of kinetic energy, but most of it is spent deforming the slug when it hits since it has no jacket.

Buckshot is even worse of course, but if you want to penetrate armor, a jacketed rifle bullet is what you want.

[V19 Experimental Build 5 available!]

And about breaching the UFO; if you want to spend fifteen turns doing that, that's your choice. Personally, I just open the door and shoot the buggers where they stand, but maybe that doesn't work for you? I generally put two shield guys in the front and have them crouch, and let them fire their pistols like mad. Then I have guys with shotguns stand behind them and fire over their heads, mercilessly gunning down anything inside. On occasion, I'll toss a C4 into the UFO, but that messes up my finances, so I try not to do that too much.

Weird, that works for you? For me, aliens inside UFO's have been pretty much impossible to hit ever since V19 Build 1. I can literally walk to the square right next to an alien and fire a five round burst with a heavy and miss every shot. It usually takes about fifty shots to kill one alien from 5 squares distance if the alien is inside a UFO. I wrote a bug about it at http://www.goldhawkinteractive.com/forums/showthread.php/6252-v19-Experimental-Ground-combat-Almost-impossible-to-hit-aliens-inside-UFO-s

[[v19 Experimental / Ground combat] Almost impossible to hit aliens inside UFO's]

Ever since the aliens started always leaving a couple of guards inside their UFO's, I've noticed this very aggravating issue. Basically, it's almost impossible to actually hit aliens inside UFO's. I've mostly tried light scouts, since it's hard to go far into the game with this issue.

What happens is this: I reach the crashed UFO and park six soldiers in a 2x3 formation right outside the door, two heavies in front and the rest riflemen. End turn.

I open the door and spot one or two aliens. Since it's a small UFO, the distance is about 5 tiles. I target it with a heavy and the accuracy indicator usually says something around 10-20% chance to hit. I fire - every shot misses. I pick the next heavy. Every shot misses. Repeat for all four riflemen - if I get lucky, I hit with one or two bullets. I move them all out of sight to prevent counterfire. End turn.

I move all soldiers back into the 2x3 position in front of the closed door. End turn.

Repeat for maybe six to ten turns until I've hit with enough stray shots to actually kill two caesans. During that time, I've probably fired a hundred bullets or so.

I've even tried running up and standing right next to the targets, firing full auto with both riflemen and heavies. The accuracy indicator at that point usually says 50% or so, but still I usually miss with all bullets. The bullets will literally go straight down into the floor or at a 45 degree angle to avoid the alien.

This happens every single ground mission.