While the reticle was designed for the 5.56 62gr round, you can adapt it to use for .308. You would just have to re-calculate for the .308 round using the ballistics calculator of your choice.
Response from Atibal:
"The XP8 BDC was designed for the 5.56, but we have had customers use it on .308s with great success. The drops for 5.56 and .308 are very similar, but we would recommend using the Strelok App to find your holds on a .308"