yeeh...if gambit got a hold of it,....he could charge it no problems....and it wouldnt' necessarily be abig explosion...thats up to how much gambit decides to charge it...
Something about its convex shape. Wait, lemme go look it up somewhere....
"The shield has great aerodynamic properties: it is able to slice through the air with minimal wind resistance and deflection of path. Its great overall resilience, combined with its natural concentric stiffness, enables it to rebound from objects with minimal loss of angular momentum."
There ya go. Anyways, it wouldn't matter if Gambit could charge up Cap's shield, Cap would just throw the damn thing at him and let it blow Gambit to hell.
but that wasnt part of the question...the question was just whether Gambit could charge it...and the answer is yes...as easily as charging a deck of cards...he was able to charge wolverine's adamantium