I just had a Benchmark barrel put on my 223 (Ruger Hawkeye). Cost me a ton to have the barrel done and have the action squared up and the stock bedded. Got it back finally and started working up loads. It shot real well, but seemed to go vertical when the barrel got hot. Well, that's not good, but probably not a deal killer. I found the good loads for 40, 55, and 65 gr bullets and loaded up a bunch of ammo. Over a week or two I shot the rifle with a cold fouled barrel to check the zero and the accuracy. I got great accuracy at times (well less than 1/4 inch) but at other times the accuracy was oddly off. I just could not figure out what was wrong. Turned out it was the scope, a Leupold VX2 6-18. Apparently the scope would start to wander on POI the more I shot it, and finally just got random all the time. I had another scope and the rifle is shooting great little groups and does NOT wander when the barrel is hot.
So my suggestion is to go with a custom barrel, but get the action tuned up while it's at the shop. And when accuracy gets odd when it shouldn't, swap out the scope. If I hadn't had a similar soope problem some years ago, I doubt I'd have diagnosed this problem properly. Probably I'd have given the rifle to a nephew and got a new Tikks 223.
And for the record, the original Ruger barrel shot quite well, though not good enough to satisfy me. Turns out that the action/boltface needed to be trued up.
