I JUST PURCHASED A MILITARY HD SERIAL #277XXX AND AM HAVING SOME PROBLEMS.ROUNDS FEED INTO THE CHAMBER FINE BUT GUN FAILS TO FIRE ABOUT 50%OF THE TIME.SLIDE WILL CYCLE AND COCK THE HAMMER ,PULL TRIGGER AND HAMMER DROPS BUT ROUND DOESN'T GO OFF.IF YOU RE-COCK HAMMER THEN IT FIRES FINE FOR A FEW SHOTS TILL THIS HAPPENS AGAIN.PISTOL HAS BEEN THOROUGHLY CLEANED AND THE MAGAZINE WORKS FINE,JUST CAN'T GET IT TO RELIABLY GO OFF. ANY THOUGHTS OR SUGGESTIONS WOULD BE MUCH APPRECIATED.