In all the games I've started or savegames I've reloaded, the 12.7 has been extremely rare as a random drop for me (I don't like to kill/steal from friendly NPC's) and while I know it's possible I don't personally want to go through the entire game with the 9mm or even Maria, especially on VeryHard where my dmg. is halved or something.
Occasionally later on the Legion guys who like to ambush me drop 12.7's but not often. Looked on the wiki and all it says is the 12.7 can be bought at certain shops at "higher levels." Does anyone know what level, more specifically? 15? 18?
Also...best perks for non-revolver pistols? Or do they all apply to both equally.