Some barrels like forward support, most don't need it.

It has been said by some very knowledgable rifle builders(Charlie Sisk & others) that the 7mm Mag "can" be difficult to get to shoot well. That can usually be solved by reloading and finding the load it want's or perhaps searching and finding a factory load it likes.

Just passing on information I have absorbed from others over the years :-) Good Luck ... Jim