Scope mounting to maintain zero

[ResearchinStuff]

The dinky screws are absolutely part of the problem. Base screws tend to be the smallest, that's why it's best to use an integral rail if available. Next best is a bonded rail.

 

[Choupique]

would be significant advantages to using larger diameter screws

Probably, but they may not be significant. Theres too many variables. Something that has to be dealt with is the universal nature of the parts involved. The rifle is made for everyone's mounts, the mounts made for every rifle, the torque values based on the tapped hole being steel or titanium or stainless etc. They're as universal as possible for economy of scale which makes good joint design impossible. You might only accomplish distorting the mount or the reciever more by using bigger/stronger fasteners. I don't think it's really worth modifying stuff and then marrying yourself to custom bases from that point forward. Just "glue" it all together.

If the failure mode is slipping, dowel pins would be "better" without having to tackle the fastener problems. Thats how you handle it with machinery when you either can't or don't feel you need to get adequate clamp load from foundation bolts. Thats basically what a pic rail and cross bolt rings gets you, assuming they fit very tight and are installed properly. The factory supplied tikka rings do this with a pin, nightforce rails with a lug that indexes against the receiver bridge. Those kind of features can make a big difference here, since we have such light clamp loads.