HAENEL 28 PISTOL

Made around the mid 1930s, this pistol, .177, No. 12741E, had a broken cocking link when received. A strip then showed the absence of a piston head. Major operations were thus to fit a new piston head and make a new cocking link. On a working pistol, a button on the rh side, near the breech, is pressed to release the grip section from the cylinder. The grip then swings down and back, pivoting at the rear of the cylinder to compress the spring and engage the piston on the trigger sear. The barrel is not used to cock the pistol but pivots on its own pivot to allow a pellet to be loaded once the pistol is cocked. Overall the pistol is very easy to work on with only screwdrivers and pin punches being required, although I found a means of clamping the pistol cylinder to be needed when refitting the mainspring.
To strip, remove the grips, one screw each side. Unscrew the end cap. Be prepared for the sudden release of the cap under spring pressure as there is considerable (about two inches) of preload. Remove spring and spring guide. To remove piston and with the grip action still locked to the cylinder, pull the trigger and, with a finger inside the piston, withdraw the piston over the trigger sear. The piston cannot now be removed until the cocking link arm is lowered ... either do this by pushing the end of the link in the grip body or push out the pin that the cocking link pivots on and remove the link. The pin has a large flat end c. ½” diameter that fits snugly into the grip frame. As you remove the link, note the spring leg that fits inside a groove on the inside of the link. There is no need to remove this spring but if you wish to, there is a pin that holds it in place.
With the link out of the way, pull the piston free. On this pistol there was no leather piston head. There was an end plate with a countersunk central hole but the hole looked as if it had been filled with solder. I guessed that there was originally a screw that went through this hole and secured a leather sealing washer. So I tapped the hole at 6mm and made a leather piston head, securing it with a 6mm countersunk bolt and a lock nut inside the piston. I place this in neatsfoot oil to soak while I continued.
There is no need to remove the barrel unless there is good reason. If you wish to do so, simply remove the retaining screw and main pivot bolt.
My cocking link had broken at the end that contacts the piston to push it back. I thus needed to make a new link. I found out that a reproduction link was available from JG Airguns in the USA for $50 plus postage but decided to continue making my own. I was kindly sent a picture of the grip frame complete with cocking link and from this managed to produce a life size picture of the link that I then used as a template to make a new one. A piece of ¼” (actually I used 6mm) steel plate and several hours work with hacksaw, bench grinder and various files later, I had a good first model link. The pin hole in the centre that secures it to the grip frame was 4mm. Refitting the piston minus the spring showed that this first link could move the piston into the cocked position. When doing this it was important to ensure the small leg of the link spring was located in the groove on the inside of the link. By unhitching the link from the piston and pushing the piston fully home in the cylinder it was possible to fine tune the link to ensure that the piston was fully home with the link attached. Care had to be taken to make sure the link was shaped correctly in order not to catch on the link spring body nor on the top of the pistol grip frame. When all seemed well, I case hardened the end of the link where it contacted the piston body.
The pistol was then ready for final re-assembly. The piston, lightly lubricated with moly grease on the outside) was pushed home over the trigger sear and the new link put in place, making sure that the end of the link contacted the piston body and that the link spring leg was located in the groove on the link. The link retaining pin was then fitted and the piston pushed fully home.
The spring and spring guide (light coating of moly grease) were added and the cylinder clamped in a rubber padded vice before the end cap was screwed back on. There is considerable preload. I found it easiest to use a block of wood to push the cap onto the threads with my right hand and use my left hand to turn the cap to engage the threads. The grips were then refitted.
Cocking is not the easiest operation and considerable effort is involved. During testing I almost convinced myself that the spring I had found in my pistol was not original such was the preload. But a photograph of a pistol plus spring convinced me that my spring, at 23 coils, was correct.
After a few test shots to settle the action, I decided to chrono the pistol. From various fora I had expected output to be around 300fps with Hobby pellets (7gn) so was very pleased to record an average of 340 fps with excellent consistency of +/- 4fps.
Phil Russell