03-13-2023, 02:44 AM
It's not about the cost of shims. It's about the fit between the barrel extension flange and the receiver. I wrap extensions with stainless stock to achieve a press fit between the extension and the receiver tube. From tearing down uppers and reassembling them, I find this improves accuracy by about .25 moa. I don't care what the barrel nut looks like under the handgaurd. Based on my experience, I would not want a shim between the receiver face and the extension flange, if I could avoid it. I would rather cut off a tooth. In fact, I prefer handguards with nuts that don't have to be timed for this reason. For what it's worth, I have rifles that have shims between the nut and the receiver, but I prefer otherwise. YMMV.