check your ammo for out of roundness,bad cartridge rims etc,,, or lack of lube on the the rails or bolt head,,caution,,saftey on ,,,,load a round thru the ejection port and slam the bolt closed,,if it locks up then it could be a worn firring pin spring or pin,,,if it don;t,,,check your bolt head or bolt head pin,,for wear,,or your recoil spring is going,I don;t shoot from the hip but that won't stop your M1014 from firring and neither will your optics..this weapon is made to fire in all condtions and positions.