bedding of the barrel is an issue that has to be tried and tested to see what the gun wants , some guns shoot best with the whole barrel bedded other shoot best with the barrel floated.
Personaly I perfer to have a barrel free floated.
When I bed a gun I pillar both front and back and glass the front of the action generaly say like on a Rem 700 I'll bed from the mag well to about one inch in front of the recoil lug. In wood of Synthetic stocks I like to have my bedd at least 1/4" thick so I remove a good bit of material from under the front of the action , I don't believe that skim bedding does any good unless you doing it on an aluminum bedding block. Also , I only use Brownells Steel Bed kits , I feel that I get a better service and results with it than other epoxies and JB weld type things , yea it more expensive but I feel its worth it (never tied Marine-Tex)