doublegunshop.com - home Forums General Discussion DoubleGun BBS @ doublegunshop.com help on changing nipple

I have a mid. 1800,s Blisset (Liverpool) 17 bore double with a broken nipple. My first idea for removal is to mill out most of the old one and try to pick out the remaining threads. I am leery on applying heat because of the soft solder joining the barrels. I would appreciate any suggestions from someone who has faced this job themselves. Also has anyone re-tapped old Damascas
nipples.Thanks

I've never removed a nipple but with bolts I drill and use an easyout with some penetrating oil

Usually the breech itself is not Damascus (never seen a Damascus steel breech). I have used the mutitude of penetrating oils and after weeks of soaking those,I did CAREFULLY drill out the old nipple. I started small and then worked up in size. Almost all nipples in shotguns, that I am aware of, start out as 1/4-28 thread. You can try the easyout like Mike suggested. I drilled out the nipple until I could collapsed the old nipple and withdrew it that way. Special oversize taps and nipples are made, in .005 increments up to about .285. Of course try not to go larger in size, but make sure you do have good threads to hold the nipple safely.

Drilling out the nipple or any screw to the root diameter of the thread and then picking out the remaining thread can be difficult. First you need to be certain that you are drilling dead center or you will wipe the threads off one side. Easy outs are great if they work but dont break one off as they are hardened and can't be drilled out if you break it. Being a welder I use a different method. Using a TIG welding torch I build up a small tit onto the broken screw untill it is large enough to grip with a vise-grip or weld on a nut. Then I attempt to back the screw out. The heat from the welding is often a benifit to loosening the screw but not enough to cause melting problems like you describe. I have done this hundreds of times with great results. If it does not work you are no worse off than you started and you still have the option of trying to drill out the screw. When it does work you have a perfect and original tapped hole left to install a new screw or nipple into.

Bill G.

I haven't had to remove a nipple but I will say that Kroil + time has worked for me in a number of situations.

I wanted to pull the barrel from an Enfield P-17 which are famous for being all but impossible to remove without a relief cut and 6 foot cheater bars and even then I'd probably bend the action. I stood the action muzzle up in a corner of my bench and whenever I noticed it there I'd put a few drops of Kroil on the barrel/receiver joint.

This went on for three months before I decided to attempt to pull it. I set it up in the barrel vise, attached the action wrench. I dropped a hand wrench and as I bent down to pick it up I leaned on the action wrench and the action spun right off.

If you have the time, a little Kroil every few days, then a drill and easy out may do it.

A nipple with a clean break is easier to drill out than a broken screw because the drill will tend to stay centered and not wander into the female threads. I have had good luck with left hand drill bits because with the counterclockwise rotation, sometimes the bit catches and unscrews the broken piece. Always be patient and use a GOOD penetrating oil giving it as much time as you can to work. Recoilrobs' experience with weeks of soaking on a barrel is a good example. I have soaked screws with Kroil and others for days and found totally dry threads a short way down, and credited my sucess to luck. Incidentally, the absolute best penetrating oil I ever used is Cabots' TASGON. It was banned by the EPA in the 1970's because it contains creosote. I have about a pint to last the rest of my life and only use it for extreme emergencies. Watch for it at flea markets and garage sales and guard it with your life. It makes Kroil, PB, Liquid Wrench, and a dozen others I have tried look like weak tea, even on heavily rusted parts. Stinks like the devil when applied daily to rusted exhaust manifold studs, but a week of that has let me break and easily remove nuts on studs that were literally half rusted away in the middle. You can repeatedly heat a pointed copper rod and locally apply heatings to the nipple to get repeated expansion and contraction to help loosen the threads. Vibration from tapping or even an electric engraving pencil may also help the oil find its way down the threads. Last resort on a valuable piece is to find a good EDM machinist as the EDM process will eat away the broken part and not damage the female threads. Good Luck.

Does anyone here recall desicanted kerosene and how it is made? Some time ago i read that it worked the best at penetrating rust. To the best of my recollection, it involves super drying salt in an oven and mixing it with the kero. I think the kerosene is then poured off and either used immediately or kept air tight. TIA H