/ɣ/ became /v/ but only if the /ɣ/ appeared originally between high labial vowels /u/ and /y/, otherwise lost entirely (cf. suku 'kin, family' : suvun [genitive form] from earlier *suku : *suɣun, and kyky : kyvyn 'ability, skill' [nominative and genitive, respectively] from *kükü : *küɣün, contrasting with sika : sian 'pig, pork' [nominative and genitive] from *sika : *siɣan). (A similar process explains the /f/ pronunciation for some English words with "gh", such as "tough".)
О как! А не симилар ли процесс иксплэйнз /в/-произношение "того"/"его"/"красивого"? Никогда не догадывапсь сравнить их с tough.