I bought a T/C Custom Shop pistol barrel used. It came with a standard Weaver base. It hung out over the taper a good bit and looked awful to me.
My solution was a call to Virgin Valley. I Bought one of their mounts and since I was not using 3 rings, I had them cut the base down at the first forward notch. Now it fits perfect with very little hanging over the taper.
If I recall correctly, this base was not expensive and they modified it at no charge.
Hope this helps,
Smoky