Did you fire this brass in your gun? Brass from a semi auto .308 may be over sized and you will need the small base dies.
If you fired these in your gun, you should be able to resize them. YOU ARE NOT OVER LENGTH at only .018" over trim length. Trim length is usually .010 under mfg spec to allow you a couple of firings between trimming. This should NOT keep you from closing your bolt. If you were .050" over, then maybe the bolt wont close, or it will close hard. (Unless you have a match chamber which you don't or you wouldn't have to ask us the question.)
Go to your press. Unscrew the sizing die about three turns and unlock the lock ring. Screw the lock ring up about two turns. Pull the press handle down so the ram is all of the way up. Take your hand OFF the press handle. Screw your die down until you cannot screw it down any more by hand. Now, while holding that die with one hand, pull up on your press handle. You should be able to feel that die move just a little. This is the little bit of tolerance difference in the threads. You should also have smooth upswing of the press handle. Now turn your die down just about 1/16th of a turn. (On my press I watch to see one or two letters in the RCBS printing on top of the die move.) While still holding that die, push your press handle down. You should feel the ram touch the die. You should feel the die move a little, and then you should feel that press handle move as it "cams over" at the bottom of the stroke. You adjust your die down to where that little bit of movement in the die disappears as the press handle cams over. If you have to FORCE the handle to cam over, you have gone too far. This is full length sizing!! Screw the lock ring down and lock it.
For my bolt action guns, I screw the die down until it touches the shell holder, then I lock it in place. I will size the brass and see how it fits in my gun. If bolt doesn't want to close, I start to adjust the die as referenced above. ONLY, I don't keep turning die down untl all the slop is gone. I will turn it down 1/64th of a turn, or 1/32nd of a turn, lock it in place, and size a brass. I see how the brass fits my chamber and how the bolt closes. I will adjust the die down sometimes 10 times before I just get that bolt to hit the sweet spot where it locks down with just the slightest hint of hesitation at the very bottom. If it feels like your bolt is opening and closing super freely on a brass you have previously fired in your gun, you are over sizing it and will work harden the brass and lose case life. If you do the minimal sizing to get that bolt to close, you will hit optimum sizing for accuracy and brass life for THAT GUN.
Once you get used to adjusting the sizing die, you screw the die down and cam the handle back and forth so fast it just becomes second nature to hit that ultimate setting for full length sizing. HOWEVER, do not do this setting for a carbide die for pistol brass. You can crack your carbide insert. You only want to size enough of your pistol brass to seat the bullet anyway.
Just 2 cents worth of info for a nickel job.
Steve
