[mdmtj]

Heres a very easy way to get the seating depth for your rifle and have next to zero headspace. Take and empty case, seat a bullet just enough so the it is held firmly in the case, now draw the bolt back on you rifle, gently slide the round in the chamber and now let the bolt come forward and push the bullet into the case. Now draw back the bolt, and let it go forward again, and one more time....now what youve just done is seated that bullet specifically to that rifle. Double check the OAL to verify its in spec and youve done this correctly. Now you can reload away and they will all feed and fire just fine.

I use this method with my AR and my bolt action .308

These rounds fit in your AR magazine? If I used this method the resulting round wouldn't fit in my magazine.