I have shot two, one in 30:06, one in 375 H&H. Both were remarkably accurate. The 30:06 was regulated at the factory for 150gr loads and would shoot four of them into under 2" at a hundred yards. I recall showing the target to the instructor at my club and he was astounded. The 375 put 300gr Noslers (Federal loads) into a not much bigger group. Both were later fitted with QD scopes (G&H and Hugh Lomas, respectively) and shot just as well.
The rifles came from the custom shop with signed targets identifying the loads used.
As for strength, the Browning action has those big sidewalls and large underbites, so I wouldn't have much fear for them unless one put much hotter loads in them and shot them quite a bit.
