Home Forums Hunting & Shooting Gunsmithing Best penetrating oil?

I rank Kroil number one closely followed by PB Blaster. Allow the Kroil to work for a few hours.

It is either a rust or thread locker issue. If you have directed the Kroil or PB Blaster to a couple of different openings to the threads and let it work a couple of hours and that didn't help, then it is most likely heavy thread locker and you will need some more heat.

If the receiver sight is an aluminum Williams, you may be dealing with oxidation of the aluminum. The only solution to that other than drilling the screws out is more heat, to the point of ruining the sight.

Also have you looked closely for any "staking" of the heads? Sometimes they disrupt the body into the screw slot or some other area of the screw head.

Again as staded earlier, try tapping a sharp rap with a screw driver bit in the screw slot, straight down after the Kroil soak/work; this will break rust free, but have about zero influence on aluminum to steel oxidation.

Just an FYI: Anti-sieze should be used on steel screws going through or into aluminum to prevent that nasty bauxite oxidation.

edited for spelling