I Know You're Dying To Know

So you can sleep at night...

.22 WMR #12 shotshell.

Damage is 1d-5(0.2) pi-
Range is 6/127
RoF is n277 (+8 to hit from the Savage!)

Note that damage...  You need to roll a 6 to do a point of damage.  Oops, that's just for crushing damage!  All other attacks do a minimum of 1 point regardless of negative modifiers, so 1d-5(0.2) pi- always does 1 point of basic damage.  DR 0 things get DR 1, so that point is nullified on anything.  pi- halving the damage that penetrates is just icing on the cake.

Your only chance for doing any damage at all is under the Flexible Armor and Blunt Trauma rules on p. B379.

Let's assume a skill of 14 in Guns/TL8 (Shotgun) and we aimed one turn.

At three yards we're -1.  +8 for the number of pellets.  +5 for Acc.  That's 14+5+8-1 for 26 net.

I roll a 10 to hit.  With Rcl 1, that means 17 pellets hit.  On average that's still 0 points of damage, but if we get 10 sixes in there we do a WHOLE POINT thanks to the blunt trauma rules!

Teeny shot sucks.

Update:  I forgot the extremely close range shot!

At 10% 1/2D range ≈ 1 yard; you lose the +8 to hit from lotsa projectiles but gain a x138 to damage and x138 to DR.  So while it does 138 points of basic damage at point blank range the pi- part means the unarmored foe get their DR 1 raised to DR 138...  However, this is the range where the blunt trauma rules really kick in!  13 points of blunt trauma will be applied!

At one yard a .22 WMR shotshell is a far better deal than ball or hollow points, in GURPS with the rules as written.