i have an axis xp in 308 and now im looking for another. i see i can get the axis heavy barrel for about $15 more than the base axis. i can then use the $50 mail in rebate on the heavy barrel bringing it in the $250 range. my question is, what is the difference other than the barrel between the two? same triggers? stock? same rifle basically 1.5lbs heavier and a beefier barrel? thanks for any info