I would be wary of mixing AR 15 components with an 308AR Buffer system, unless you plan on using Armalite AR 10 Buffer assembly , including the Receiver Extension , 308 Buffer spring & a Heavy H3 AR 15 Buffer . With the Tubb's spring , as said there is no need for a Heavy Buffer .
No offense to Clint , but he is selling a system & the Tubb's spring would contradict his system he is selling , direct competition . Nothing wrong with Heavy Buffers or the system he sells, just two different ways to accomplish the same thing .
My Magpul CTR & ACR both have a locking system to lock down the stock . An Adj. Stock is just that , it can be adj. for length of pull or those who find a Rifle stock too long , not to mention if you are wearing tactical gear .
You wanted an A2 stock , just stick with it & a 308AR Buffer & Spring & you will be fine , add a Brake or Compensator for a Muzzle Device & your 18" barrel & the rifle will run smooth as silk , now if you start swapping incompatible components , you will most likely have issues , Keep it simple with the correct components & it will be smooth sailing .