252 SpA Mega Salamence Dragon Pulse vs. 4 HP / 0 SpD Garchomp: 158-188 (85.8 - 102.1%) -- 12.5% chance to OHKO
252 SpA Mega Salamence Dragon Pulse vs. 4 HP / 0 SpD Kommo-o: 134-158 (88.7 - 104.6%) -- 25% chance to OHKO
252 SpA Mega Salamence Dragon Pulse vs. 0 HP / 4 SpD Hydreigon: 150-176 (89.8 - 105.3%) -- 37.5% chance to OHKO
252 SpA Mega Salamence Dragon Pulse vs. 4 HP / 0 SpD Mega Salamence: 152-180 (88.8 - 105.2%) -- 25% chance to OHKO
Rule 1 of Doubles: Don't roll dice unless you absolutely have to.
-------------
252 SpA Mega Salamence Draco Meteor vs. 4 HP / 0 SpD Garchomp: 240-284 (130.4 - 154.3%) -- guaranteed OHKO
252 SpA Mega Salamence Draco Meteor vs. 4 HP / 0 SpD Kommo-o: 204-240 (135 - 158.9%) -- guaranteed OHKO
252 SpA Mega Salamence Draco Meteor vs. 0 HP / 4 SpD Hydreigon: 228-270 (136.5 - 161.6%) -- guaranteed OHKO
252 SpA Mega Salamence Draco Meteor vs. 4 HP / 0 SpD Mega Salamence: 230-272 (134.5 - 159%) -- guaranteed OHKO
Rule 2 of doubles: Overkill is a myth perpetuated by the smoldering craters of my enemies.
-------------
Yes, Kommo-o has the same special bulk as MegaMence which is almost equal to Garchomp, I too learned something new today.
Also, for Kommo-o specifically:
252 SpA Aerilate Mega Salamence Hyper Voice vs. 4 HP / 0 SpD Kommo-o: 126-150 (83.4 - 99.3%) -- guaranteed 2HKO
252+ SpA Kommo-o Clanging Scales vs. 4 HP / 0 SpD Mega Salamence: 188-224 (109.9 - 130.9%) -- guaranteed OHKO
cant say your calc has 252 Atk / 0 Sp. Atk for Kommo-o's Modest "Special Attacker" set, please fix before I forget <3