Heanel Mod 1 DRP, Fixing and reassembly

Heanel Mod I DRP

Even though this air rifle was 75 years old there were still a lot of sharp edges on it, so I needed to get the draper mini drill out and deburr the compression tube. 

I thought it wise to clean the inside first as I didn't want to clean it with bits of deburred metal everywhere. It would also be nice to see if any damage had been caused by the nail that was embedded in the leather piston seal.

Hole left by the rivet in the piston face.

I used medium guage wire wool clamped onto and wrapped around the cleaning rod, it was dipped in white spirits and the inside of the compression tube was given a good all round scrub, and this was followed with a fine grade wire wool and then kitchen towel. 

Coarsest grade of wire wool removed most of the crud.

The inside of the compression tube was mirror smooth and shiny along the whole length, however some of the leather piston seal had stuck to the end of the tube, so I carefully chipped this off with the end of the cleaning rod. Now I could see that there were slight markings below the transfer port caused by the head of the nail, though these were nothing of concern. I did notice that the transfer port ran from the centre up to the barrel and by using the cleaning rod as a guide could see it was about 3 cm long.

White spirits stops most of the crud from collecting on the outside of the wire wool.

Using a craft blade I scraped the hard surface off the leather piston seal and shaved off any lumps and bumps off the face, 

A sharp blade brings life back to what appeared to be one knackered piston seal.

but not from around the hole left by the nail. Pouring some 3 in 1 oil into a milk bottle lid, I put the leather seal in to soak for a few hours.

Soaking in 3 in 1. A red plastic back plate give a flat surface for the leather seal to sit on.

When it came out, I placed it on a kitchen towel to soak up the excess, then pressed hard against a table surface. 

Remove as much excess oil as possible, it's going to smoke for a while as it is.

The seal appeared to have a new lease of life and a compression test proved there was new life in it now. Leather seals need a quick push to start to seal the compression tube unlike O ring and parachute seals which will seal straight off.

One restored leather piston seal.

I deburred the cocking slide and the pivot pin holes from the inside of the tube, 

Still has sharp edges after 75 years.

then screwed the grub screw for the barrel lock bar right in and deburred any metal created by the cocking linkage. 

That grub screw should come right out now.

White spirits and kitchen towel were used to remove any metal grindings from the inside of the compression tube, then I used 3 in 1 oil on some 0000 wire wool and cleaned every external surface of the rifle while it was dismantled.

0000 wire wool and oil removes rust but leaves whatever bluing is left on the action.

Now the leather piston seal was soft with no excess oil when pressed. It was screwed back on to the piston body, then the piston unit was replaced in the compression tube. 

A polish and light greasing.

The trigger housing has enough spring tension to hold the main spring in place with its preload.

With some Abby LT 2 grease liberally spread over the original main spring and spring guide, they followed on behind. I could always order a new spring later and this one was still a lot stiffer than the length of spring I ordered a while back.

The original main spring.

The trigger housing inner sleeve was still well and truly spring loaded and with it lined up, I carefully squeezed the forward end into the rear of the compression tube. I then gently tapped the rear of the rifle against the floor until the inner sleeve was back in place. 

This shows how much spring tension there is in the trigger housing.

The spring tension of the sleeve was enough to hold the main spring under preload and with the aid of a screwdriver the holes were lined up, 

All lined up.

the trigger was lined up and the pivot bolt fitted. With the safety in the off position and the trigger pushed forward, I replaced the end cap. With the end cap lined up, the retaining pin was fitted, it required the aid of a hammer to drive it home fully.

That pin takes some effort to fit as well as remove, so bear that in mind if you have to do this.

This was finger tight as there is a cut out in the stock for it to fit in.

The grub screw that holds the barrel locking detent bar unscrewed easily now that the end of the hole had been deburred.

A fair bit of wear and tear on this grub screw over the years, but it was easily fixed.

The bar and spring were removed, cleaned, greased with a little LT 2 and put back, with the head of the grub screw in a little deeper so that the cocking linkage wouldn't damage it again. 

Detent bar and spring all cleaned up.

 With a little grease on all the moving parts, the cocking linkage was slipped through the bridge and slotted into the compression tube, 

Guide for the articulated cocking linkage and threads for the fore stock screws.

the unlocking latch and breech were placed back in the forks and the pivot screw was replaced followed by the locking screw.

The pivot bolt goes in so much easier with the barrel broken.

It was a lot easier to tighten the breech pivot screw with the barrel unlocked as if it was ready to load, and this was without a breech seal in place.

The old leather breech seal was well beyond repair so I resorted to my trusty box of rubber O rings, 

Leather breach seal well beyond repair.

I did not have a three mm O ring of the right diameter so I cut one to the right size and super glued the ends together. 

New breech seal made from a section of rubber O ring.

It was made a tiny fraction larger so it would sit in the breech under its own pressure, the breech was closed to push the seal all the way home and a perfect seal appears to be produced.

New rubber breech seal fitted into place.

With the rifle lubed and put back together, I fitted it back into the stock, using a screw driver to hold the trigger tension spring back until the trigger was in place for the spring to fit over the tab.

Easing the tension spring back to fit on the back of the trigger.

Then it was a simple matter of fitting the stock screws. Each screw was fitted loosely at first allowing the action a little adjustability in the stock. This way all the screws attached correctly and then were tightened up fully. There is nothing more annoying than tightening one fore stock screw all the way home, only to find the other side won't fit.

Rifle back together, i gave the stock a rub down with wire wool to discover some lovely wood.

All I need to do now is build or bodge some sort of rear sight, the original sight is a simple affair so should be easy enough to make a rough copy. The safety still doesn't work, but I have an idea on how to remedy that, and the barrel lock could do with a new spring behind the detent bar. Anyway, the rifle fires with some authority now for it's size, but I will have to wait until I get a new chrony to find out what power it is producing.

TTFN

Wing Commander Sir Nigel Tetlington-Smythe.


   

SMK 15, Small plinker for Small People

My wife got a message from a friend of hers the other week asking if she'd know of anywhere she could sell her sons old .177 air rifle. He was no longer interested and Mum was aware of my hobby (obsession) with air rifles. Wife says " it's never really been used and it's got SMK and 15 written on it, oh and it's got a scope and gun bag with it". She won't get a lot for that I thought, i'd give her 20 or 25 quid at the most though I could suggest a few sites she could advertise it. Seems she was happy with 25 because a week later we're off to pick up the wife's new air rifle. I hand over 25 of our English pounds and in return I am given a very well padded gun bag with an unknown quantity of wood and metal inside it. Mmmm, this should be fun, I thought!

As it came, Rifle, Scope, Gun slip, and bits and bobs.

The SMK XS 15 Supergrade  air rifle is a junior size Chinese air rifle very much along the lines of the Webley Cub. For 70ish quid you get an air rifle and a 4x32 scope. Now this is an older version of the same deal coming with an extra gun slip, two packs of .177 darts, and an abrasive cloth for cleaning the gun. I would say it's about 10 years old owing to the fact that the open sights are not fibre optic, which to some people is a good thing. I reckon they're OK on some rifles, but I would be mortified if they were on my HW35, if you know what I mean!

The front sight is a square post in a hood on a raised slope and has no adjustment, apart from the post, the sight is made from a molded plastic which fits around the end of the barrel.

 The rear sight is adjustable for both elevation and windage in the traditional style and is also mainly composed of plastic, however it makes a clear and crisp sight picture when aligned with the front sight. The wheels turn with nice pronounced clicks, and there is no looseness to them at all.

When I tested the rifle, it was pretty accurate with open sights but with the scope fitted you could see the rifle could do with an internal overhaul, or maybe it was just typical of an old Chinese air rifle. We shall have to see.

The rifle having been stored for ages had tiny little rust spots all over it, so some very fine 000 wire wool and gun oil soon had those removed.

The wood was in really good condition apart from a tiny nick at the front of the stock.

I don't know what wood it is, most likely something cheap, but still looks of reasonable quality - the wood on my SMK multi pump is awful in comparison!

The SMK sign could be seen through the the half decent bluing. It has a blackness to it that is common to all SMK's I have found, not very deep.

The end cap is made of plastic along with the safety catch, the end cap being held in place with a steel pin.

 

The safety sets on cocking and pushes in easily at the rear like many Diana air rifles. I'm truly tempted to paint the white dot red but alas it is not my call.
.

The breech is held between the forks by bolt as opposed to a pin, which is always a bonus in my opinion, and a locking screw keeps the whole business in place.

The trigger is made of pressed steel and is not too heavy, it feels as if there are two stages to let off though I imagine there is no adjustment.The front screw of the trigger guard holds the stock to the action, along with two screws at the front which screw in diagonally up into front of the compression chamber.

The rubber butt pad is just what it is, made of rubber and screwed into the rear of the butt by two screws.

It doesn't need to be ventilated or anything fancy as this is a junior rifle and fires lightly with no major kick to it, and it takes very little effort to cock the gun.

The break barrel breech is held in place with a ball bearing and spring, which with the power this puts out should do the job nicely. Though wear and tear could see problems with vertical accuracy, which is a shame as the breech block is bolted horizontally.

The breech seal looks nice and healthy so I can't see any problems there for a while. In fact when I took the rifle out to the woods for some free hand practice it was surprisingly accurate at ten yards, and at 25 yards could hit a drinks can every time.

It's a junior plinking air rifle and does what it says on the tin. It's pretty solidly constructed and feels hefty in your hands and I must admit i like how it looks. The rifle feels small to me but will fit the wife nicely, I also have a Crosman 1077 which she likes to shoot as well.

I reckon that should do it for now and im sure I will be back with a blog on the internals of this feisty little bugger, that is if it's OK with the missus for me to take it apart.

TTFN

Best wishes, Wing Commander Sir Nigel Tetlington-Smythe OBE.

BSA Mercury, The Final Stages

For now.........

Sweet looking air rifle

When last i wrote a blog i had just finished fixing up the BSA Mercury, and left off with popping in the breech seal. However i realised i had forgotten to order one, just missed it out on my order from J Knibbs. So in goes another order for a Titan XS mainspring for the Weihrauch HW35, a flip up red filter for my gun lamp, and two generic BSA breech seals, I got two as i have a BSA Meteor which would benefit from a new one as well.

 When i gave the original Mercury breech seal a close inspection i could see why it needed replacing, one half of it looked liked it had been filed flat so one side was flush with the breech face and the other side protruded a smidgen to where it should seal. 

Worn old breech seal

When i placed a cigarette paper over the breech to see if any air escaped when fired, it didn't just move it, it shot into the air, and that was with me gently holding the paper to the sides of the breech with my fingers.

Ready to replace

The generic breech seals are made from a firm rubber and are white, where as the original is a black harder harder material, but that may be because it has aged and hardened. 

Two new breech seals, i have a Meteor as well.

It's a folded over circular seal with a small slit on the inner fold, and the fold is the side of the seal that faces the outer side of the breech. The old breech seal had to be prised out and as it was so old it came out in small pieces and crumbs, most definately well past it's sell by date.

Oh crumbs!

Though once removed and cleaned the new seal just slipped in easily and straight away i could tell the differance between the old worn seal and the new one, standing just past flush from the breech face and making a perfect seal around the transfer port. 

New breech seal fitted

Cocking the rifle and loading the pellet then taking the shot i could hear the pellet hit the back stop with a lot more force than it had done before. Though i would like to point out that according to a very well known and experienced airgun tinkerer (known to some as T20) reckons that most Wiehrauch breach seals would fit even better to Meteor's, Airsporter's, Mercury's, et al, and give you an extra 1/2 ft/lb as they are made from tougher stuff and are a tad longer. Anyway read his blog 'Air Gun Tech' and you can see for yourself that him and his buddies know their minerals, it all makes sense to me, sort of.

I also made an order to Uttings for a 6x40 AO Nikko Stirling scope and a set of Accushot high profile off set mounts, the mounts arrived but i would have to wait another week or so for the scope as they were out of stock.

Lots of bit's that come with the scopemounts

Scope mounts in the box

I have discovered that after buying loads of economy scopes in the past that it's best to spend a little bit more, though you don't have to break the bank doing this. 6x40 is a good hunting magnification and Adjustable Objective is pretty handy for guaging the distance of your target, and being a little short sighted i can use a scope with AO with my glasses on. However they didn't have any in stock several weeks later, so i reordered a 3-9x40 AO Nikko Sterling and i can just leave it on x6 mag for hunting

Ready to fit the scope

The one piece off set mounts are crucial for BSA Mercury's and any other BSA with the curved trigger unit, as the scope rails are set to far forward for most people to use comfortably with normal mounts. In this case i  mounted an AGS 3-9x40 scope and with the off set facing backwards found it sat just perfectly for my head an eye to line up, two hex bolts clamp the mounts to the scope rails and two smaller hex scope stops screw down to add extra support on the top or the piston cylinder. The Accushot mount came with three allen keys and one spare hex bolt in each size, this was handy as i had a one piece mount with a striped hex head so i popped it in there. The hex head was a little thicker than the others but it does the job fine, and now i have a spare one piece mount for one of my other springers.

Out in the back garden i sat down at 27 yards from my target and trap and took some test shots with .22 Eley Wasps No2's, The scope was fairly close to the POI but the shots were stringing vertically and some went left or right which showed me this rifle would need at least half a tin of pellets to settle down and a very gentle hold, though when i tried some .22 RWS Superdomes i found the grouping was a hell of a lot better but still not upto anywhere good enough for hunting. Most Super domes fitted snuggly into the breech though some were looser and deep seated themselves. However i could feel the wasp's click in snuggly, but they can be seen by eye that they all differ or are slightly deformed in some cases, and would explain why I found this a little odd as old BSA barrels are 5.6 mm and Wasp No 2's are made for this and they just did not perform that well, where as the super domes that fitted deeply where falling into roughly 2 inch groups which was without a doubt an improvement.

With the new main spring and lube this rifle slams the piston home with force but there is no buzz or twang which is a bonus, but for a smoother lock cycle it is in need of a top hat and a slip washer and 3 or 4 coils removing. I feel this air rifle is now performing close to if not a little above factory specks, but give it a bit of running in to settle the spring in and short stroke the piston and its going to be a corker of an air rifle which is not so hold sensetive.

I mean, i shoot at a dot on a piece of paper and my shots appear to go all over the place, but if i place a few bits of 1 x 2 inch wood on the shelf in front of my back stop and i miss one every 5 shots. So it seems i can hit an inch size object better than i can group an inch circle on paper, and that's at different ranges to boot. Now that's all well and good out in a field of rabbits where i originally learn't to shoot well, but i have to garrentee i can do that with whatever air rifle i am using at the time in order to make a clean kill. Most of my air rifles will allow me to do that out to 45 yards in some cases, but with this rifle as it is now i wouldn't like to take the chance, even at 15 yards.

 It would appear that i still have a lot of work to do on this lovely little Mercury, and as this blog is all about my learning curve with working on air rifle dynamics and the improving of my knowledge of said objects. Then it would stand to reason that i will be squeezing a few more blogs off this gun.

TTFN

Wing Commander, Sir Nigel Tetlington-Smythe.