Sunday, April 17, 2011

Haenel 303-Super Tear Down Part 3

Still operating on the assumption that the transfer port is too large in diameter. The easiest solution is to sleeve the port down to a smaller size. 1/8" was the size Cardew favored from his research and I'm in no position to argue.

Some brass tubing from the scrap box. The ID of the tube is 0.125".

Test fit. The port is drilled at an angle. I'll assume that the angle at the breech face is identical to the angle of the inside face of the compression tube. I filed the brass tube to match the outside angle, turned it around and turned it over. An index line scribed on the tube made this easier than it sounds.

Because this can't be quick and easy, the tube is too loose in the transfer port bore. Knurling the tube will expand the OD a few thou.

It'll also give the epoxy something to grab.

Was pretty liberal with the JB Weld. If it doesn't work, the brass will easily drill out and Cardew and I will have something to talk about.

A 3/4"rod held vertically in the vise acts as a stop inside the compression tube for the blind end of the brass tube.

Cleaned up the excess JB Weld from the breech face before it hardened.

Cut the tube off flush with a jeweler's saw.

Finished the breech end.

Back to that too short spring guide. Found some likely replacements in the scrap box by test fitting them to the ID of the mainspring. A piece of o.500" cold rolled tubing and a spare Weihrauch spring guide made the final cut, but the HW won by virtue of a better fit to the spring. For what it's worth, the HW guide is 0.514" in OD.

Punched out the stock sheet metal tube. This was easier said than done. I expected it to pop right out, but no, Haenel had reduced the diameter of the tube, inserted it from the front, then rolled that rear flange. Tip of the hat to them for permanence, but I'm scratching my head that they put so much effort into fastening what's no more than a piece of too short, too small diameter, sheet metal. Uh, way to go guys?

Cut the tabs off the HW spring guide then through drilled it so the Haenel piston rod would clear.

Of course, the OD of the HW tube is too big to fit into the bore of the plug. Reducing the plug end of the HW tube will leave the wall thickness on the thin side.

So rather than thin the tube, I drilled the plug out to 0.500".

Then used a boring bar to open the hole to 0.512".

Set everything in the vise jaws and heated the plug with a torch. Used the vise to press the tube into the bore while it was hot.

Took a substantial amount of force to seat the new tube. Given how hard it was to remove that original guide, this one is even tighter. I think the guys at Haenel would approve.

I was getting ready to reassemble the rifle when I remembered that metal cap--or button whatever you want to call it--that keeps tension on the cocking lever. It was all scarred up.

Just a thin stamping. Almost looks like a bottle cap.

More scrounging in the metal box gave up a piece of tool steel--most likely W-1.

Turned an end down to 0.640" OD.

Then hogged out the end until the coil spring fit inside. Cleaned up the interior with a boring bar...

and parted it off.

Sanded the top flat on a granite surface plate.

Took it to 400 grit. I'll harden, then polish it so it doesn't wear out like the original.

I'll be back with more in a few days.