.22 Norinco jw15 or puma hunter mods

Improving and repairing firearms. Rifle bedding, barrel work, stock replacement and other ways to improve your firearms.

Re: .22 Norinco jw15 or puma hunter mods

Post by Gwion » 21 Feb 2018, 9:27 am

Cherza wrote:
Wm.Traynor wrote:Sounds like you have a lump attached to the barrel's under-side, like a 452 CZ. That arrangement is very difficult to deal with, I am sorry to say. Briefly then and IMO, the whole rifle should sit on the bottom of that lump and the underside of the action, at the rear take-down bolt. No contact between those two areas. Because this bedding arrangement is unlike others where there are screws at the front and rear of the action, it cannot be tested as far as I know. When I did my 452, tension on the bolt at the front "lug", was a big influence on vertical dispersion.
How far in front of the action is the lug?

That is correct its a little round dove tail lug.
Its about a inch in front of the action from memory


I know this is a few months old but..... bedding 22lr with a barrel lugs is a pain in the bum. After removing the trigger and mag receiver assembly and stopping up any voids with plasticine, you need to wrap an even layer of sparkies' tape around the lug and fill the voids in the dovetail join with plasticine (be generous and even build it up around the join: neatly: or you will have one stuck barrelled action!) and put release agent all along the action. I also build a plasticine dam about an inch forward of the lug to create a stop for the bedding compound. Obviously, all this is done after the inletting has been relieved and keyed; being sure to leave a small datum point at the tang end as height reference. Stop up trigger and mag inletting with placticine.

I then reassemble the rifle and toques down the action to get the dam to the height I want it. Once I am happy that the action is sitting where I want it in the stock, I take it apart and trim the action side of the channel dam so the bedding creates a nice straight line perpendicular to the bore.

Here's the tricky part.
If the lug screw is captive in the stock, you have to do something to prevent bedding compound binding the whole show together.
Get a screw that matches the female thread on the barrel lug. Screw it in all the way and mark the depth. Grind all the thread from the screw and cut the head off. It should now slide through the take down inlet in the stock with plenty of clearance. Wrap an even layer of sparkies' tape around the protruding rod and again use plasticine or wax to fill any void where the screw enters the lug.
I have found it most successful to then plug the lug inletting from the barrel channel side and pour in candle wax from the other side. Once set, use an appropriately sized sharp drill bit (by hand) to ream the screw hole and leave a small collar of wax all around. Your lug rod should now pass easily through the lug inletting hole in the stock and the wax is preventing bedding compound from binding the parts together.
Mask up your stock. Mix up your bedding compound and put the two pieces together. Using finger pressure, set the action to datum (the point you left at the tang and the dam you built in the barrel channel) and give a bit of a clean up of any squeeze out goo. Use heavy rubber bands (I use cut up strips of bike inner tube) just behind the barrel lug (to allow clearance of the lug rod; ideally you use two wraps and offset the bottom passes so that the pressure is even directly on the lug) and also at the tang end (directly over the datum point you left). Don't over do it. You just wand even pressure to hole it to datum. Give it another little clean up but don't go nuts because you will get some suck back as the bedding sets and (if you have masked and coated with release properly) it is easy to sand any excess back once it has cured and comes to final clean up.

Allow it to go off. Crack the action out and begin the slow, tedious process of cleaning all parts of release compound, tape and plasticine. Remove and ridges or burs left in bedding compound. Bevel and taper around any inletting for trigger and mag. Ensure the line at the end of the bedding is exactly perpendicular to the bore/barrel. Reassemble. Shoot. Set torque. Wonder why the hell you took out the pressure point bedding in the first place. Experiment with where is the ideal place and what is the ideal height of the new pressure point by shooting and testing with small strips of card board. Re-install pressure point. Shoot.

Feel proud of your work for a few months and then realise how much of a waste of time it was on such a cheap rifle but then shrug your shoulders and think, "hey, at least I learned something".

:lol:
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Gwion
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