Sunday, 18 May 2014

Heanel Mod 1 DRP Strip Down

It's been a long time since my last blog entry, but i've been so busy - a new job, fixing the garden, kitting out the new LDV, feeding the family, and of course waiting on my wife hand and foot so she will agree to let me buy new air rifle bits and a chrony! So here it is...... finally!

The Heanel after a quick tidy up with a cloth and oil.

The more I research about the Heanel Mod 1, the more intrigued I become. There's not a lot of info on the net about it but you can find a bit if you look hard enough. With a complete strip down and replacement of internals and breech seal, as well as fixing the rear open sight, it will be a neat little rifle.

Fixing the rear sight should not be too taxing a project.

There is no scope rail so the rear sight really needs to be fixed, and the safety at the back of the compression tube doesn't engage even though it does look rather snazzy.  

A solid looking but ineffective safety.

I popped a Wadcutter in the breech to see how well the rifle fired ... nothing came out of the barrel, and on inspecting the breech end of the barrel I could see the back of the pellet sitting half an inch down the barrel. The leather piston seal had most likely dried up, so adding ten drops of 3 in 1 oil down the transfer port, I worked the break barrel up and down a few times and left the rifle to stand upright for a few hours. After a wait I then cocked the rifle and fired it into a bucket of sand, and sure enough, the pellet shot out of the end of the barrel.

So with some time on my hands, I thought I would strip her down and have a shufty. 

The stock is need of some serious TLC, if not major surgery.

The stock, which is well worn with age, was removed by removing the leading screw on the trigger guard and and two smaller screws set at 90 degrees either side of the fore stock, all flat head and the fore stock screws threaded at the end as they pass through a metal cup.

The sleeve around the fore stock screws stops the wood being chewed up.

Fore stock screws threaded at the tip, very tidy.

The trigger tension spring is fitted into the stock and connects to a tab on the back of the exposed trigger blade.

Tab on the back of the trigger for the tension spring, the block next to the pivot hole is the safety catch.

Should fit back into place easily enough.

Trigger tension spring built into the stock.

The trigger pivot had a small circular nut with a flat head that screws onto a bolt with a flat head slot just like you find on a Diana 16.

Nut for the trigger pivot bolt.

This runs the width of the compression tube, and the flat head nut was only finger tight. 

Nut removed and bolt ready to slide out.

With the trigger out of the way, I could see how the safety moved and was supposed to hold the trigger to stop it releasing the latch rod. It looks like it should work unless it's just worn with age, as nothing appears to be broken.

Safety bar inside the rear of the trigger housing.

As I want to get access to the compression tube unhindered, I removed the breech, barrel and cocking linkage. 

Locking screw for the breech pivot bolt removed.

The locking screw for the breech pivot came out easily and I unscrewed the pivot from the forks, carefully as I didn't have a very wide screwdriver and did not want to damage the head. 

Breech pivot bolt unscrews a lot easier if you break the barrel.

The breech moved forward and I was able to lift the cocking linkage from the compression tube and slide it through the retaining bridge, which, like the block that holds the main stock screw, was seamlessly connected to the tube.

Some pretty spotless welding.

The cocking linkage is held together with tubes of steel that have been riveted out either end, I would most likely damage them if I tried to remove them.

Best leave the cocking linkage as is, for now.

The breech seal is made of leather and using a small flat head on a small screwdriver, I gently worked the seal out from the outer edge.

Leather breach seal is well past shimming.

It came out in one peice but looked a little beyond repair. 

One shagged out breech seal.
The leather was old and dry and some had come away, sticking in the breech seal hole, so even with soaking in oil and shimming it would not work again. Such is life, but it was nothing a peice of rubber O ring and a bit of glue couldn't fix; a new one could be made with thick shoe leather and a craft knife or correct sized hole punches.

That is a 38 for sure, makes the rifle 75 years old by my reckoning.

The year of manufacture is stamped on the breech block and here I found the number 38, so did Neville Chaimberlin bring this air rifle back with him in 1938 to tell the nation we shall have peace in our time? Most likely not, but this air rifle is a solid piece of engineering just like the rest of the German war machine of that time. This rifle is very similar to the Weihrauch HW 35 in much of it's looks and design features, perhaps it's a German thing but I reckon the influence is obvious.

Here you can see the influence on the Weihrauch HW 35.

The breech lock bar fell out nicely and I could see how it was designed to move, limited by the pivot bolt.

All holds together nicely, but not when you remove the pivot bolt.

The detent locking bar was held in place by a grub screw on the underside of the compression tube which means a very long transfer port. Years of the cocking linkage rubbing against the bottom of the compression tube had deformed the flat head of the grub screw, but being a softer steel it was easy enough to reshape the flat head. 

Years of cocking has worn the outer edge of the grub screw hole and the top of the grub screw itself.

Now I could tighten the grub screw but not remove it, this was because the cocking linkage had also deformed the end of the screw thread in the compression tube slightly.

Screws in but not out, easily sorted though.

As the safety runs through the centre of the back block, the retaining pin runs below this and was a bugger to remove as it had most likely been there since the start of World War Two, but with the compression tube in a vice, I was able to loosen the pin by gently tapping the slight overhang back and forth with a hammer. 

this pin did not want to drift out without some serious persuasion.

Once it was loosened, I was able to drift it out and the back block and safety came out.

End cap, safety, and pin. Knock the the small pin out of the safety tab and it should all come apart.

It was now possible to see a short, spring loaded inner sleeve which is the trigger housing that held the spring guide in place.

Drifting the spring loaded trigger housing out enough to get a grip on.
 By putting the compression tube vertically in a vice, I could drift the sleeve out a little via the trigger slot and then use flat nose pliers to remove it completely.

Drifted out a little and pliers will remove it the rest of the way.

With this removed, the main spring pushed the spring guide back over an inch.

Inch and a half of preload on the main spring.

The spring guide and main spring came out easy, revealing a cleanish guide and a fairly worn spring that had most likely been in there for 75 years. The piston moved easily down the compression tube with the aid of a screwdriver and was pulled out the end. 

In need of a good clean and a new main spring in an ideal world.

There was a little oil from where I had previously put some down the transfer port over the spring and piston, the leather piston head seal was grey and nasty from this oil and years of dirt. 

Old and worn leather piston seal.

When I gave the piston a wipe clean, I found a rivet embedded in the leather piston face, which was a sure sign that some numpty had ran out of pellets at one time and decided to see what else the rifle could shoot.

After a clean and there is a rivet embedded in the face of the leather seal.

Anyway, I prised out the rivet/nail and unscrewed the leather seal and spacer from the piston body, and even though there was a nail shaped hole in the piston face I reckoned I could save the seal, or at least give it a go.

And there lies the culprit.

I took the old main spring to the shed where I have a couple of lengths of different diameter spring that I once bought for some forgotten experiment, one was a fraction wider and would fit the piston, though the wire diameter was maybe a tad smaller. I also picked up a pack of three different grades of wire wool which would be ideal for cleaning the walnut stock, and I still have a load of Danish oil left that will bring out the grain a treat. So there, a few things to fix and clean and the rifle can go back together, most are already done as I write this, so further blog entries will be coming any day soon.


Wing Commander, Sir Nigel Tetlington-Smythe


No comments:

Post a Comment