I've been searching everywhere for this and can't find a definitive answer on this topic.  Many ammunition sites list .308 and 7.62x51 as if they're interchangeable, and documentation seems acknowledge that they're the same size with the main difference being the pressure.  But there are also plenty of articles that run the gamut of what is and isn't safe.

My specific question is this:  I'm in the process of acquiring an KAC M110 rifle, and would like to know if .308 is safe to fire out of it.  I can't find anything official or unofficial on this topic, and was hoping someone here might have some insight.

Thanks in advance for any information.

For some really old 7.62 guns, theres a small chance that some .308 could be problematic.
For a modern rifle it's no factor

There is a Knights Armament forum in the Industry section. If your a knights guy it's a good sub forum.

I would imagine they set it up for the more powerful 308 round, that way either 308 or 7.62 could be used without issue. Much like AR15's are chambered for the more powerful 5.56 round and .223 isn't an issue. But yeah the Knights people could tell you for sure no doubt.

Good advice, I'll give that a try.  Thank you.

I have a KAC Sr25 ECC and have shot commercial 308 Win from it as well as 7.62x51 m118LR.  You can fire either safely in It.  Don’t ever hesitate to pick up the phone and call KAC  if you have a question about it.  There are no stupid questions when it comes to anything related to the safe operation of your rifle.  Yes, go over to the industry section and look for Knights.  There are some very knowledgeable collectors on there and enjoy your rifle.  My biggest suggestion is try and acquire factory KAC metal magazines if your reloading and want to experiment with setting the OAL of the cartridge a little longer.  I can load longer rounds with the factory mags than magpul.  Yes the factory mags are stupid expensive but keep an eye out on the equipment exchange for them to pop up in good used condition.