Because I don't know the context. Is he glad he no longer had HIS OWN revolver, or is he glad that he (someone else) no longer had his revolver.You wouldn't say: "il était content de ne plus avoir son revolver".
Yep, sorry I didn't think; it would indeed be subjunctive.But! the reason i was going to use the infinitive in the first place was because I thought it was better to when there is no change of subject. If i use que here, I need the subjunctive, true? il était bien content qu'il n'eût plus son revolver???