Re: Bedding Remington 700 sps tac
First, the stock flexes so you'll want to expand the channel the barrel sits in, or get a non-flexing stock.
Bedding is using a material (in the old days it was fiberglass) which was put between the receiver and the stock and allowed to harden. In the real old days, you would bed the entire length of the barrel where it contacted the stock).
It supports and stabilizes the action.
There is a lot more to learn before you try it, and various precautions to take so you don't ruin the rifle.
For mine, I bought a stock from manners and had them bed the action.