Saturday, 30 March 2013

DIY Sping Compressor



 In the past if i ever needed to compress a spring for one of my air rifles i would use the wood lathe, it was one of those jobs where you would clamp a drill in the headstock. The tailstock would adjust by sliding along a round bar then lock in place, it had a live centre which would wind in about four inches. By placing a wooden bed above the round bar and a block of wood over the hole for the drill in the headstock, i could then secure the spring and piston cylinder to the bed at the right height for it to be in line with the centre on the head stock. This worked fine unless there was a lot of preload on the spring but i usually found some way around that. However i had other plans for the wood lathe, and that was to convert it to a rudimentary metal lathe which i did. Unfortunately the conversion made it impractical to use it as a spring compressor anymore, and besides i really needed a bit more than four inches of movement when taking a spring out.

Makeshift metal lathe from old wood lathe

Having seen other DIY spring compressors on you tube and various airgun websites i decided i would have a go myself, and the sooner i did it the sooner i could get on with tuning up the glut of air rifles i was given. Not only that but its bloody freezing in the shed sometimes, and it would be a lot warmer to work on the kitchen table with some thing a little bit more portable with easier access to to the kettle

Cylinder bed
Framework for nuts and threaded bar

There was a load of various offcuts of wood in the shed, and instead of using an old G clamp i would use some 12mm threaded bar and nuts surrounded by a plywood frame and secured with metal putty. An old piece of wooden shelf was used for the base, the end block was very hard wood in which i cut a slot in for barrels to fit through. This was butted against three lengths of wood that ran part length up the base, the middle piece being a tad lower so an air rifle cylinder would sit comfortably.

Threaded bar clamped for cutting

Handy homemade disc cutter attachment for the drill

Bar lined up, washers and nuts in place for metal putty to be packed in

As the most pressure is pushed outwards against the two end blocks i decided i would strenthen and support them with metal brackets bolted to the bed, i then made a trough for a piece of hardwood to slide without slipping when the threaded bar is wound against the back of the rifle. When i tuned the Norica Quick the cylinder was held in place with strong tape, though later i drilled two holes in the bed and popped a couple of coach bolts through them. Now i could clamp a piece of wood strengthened by aluminium to act as a clamp.

Nuts held tight, metal bracket for extra support
Plastic strip for support trough

Admittedly it did not like the five inches of preload from the Norica's mainspring, but after a little settling in it did the job fine. This one will do for now but i have a load of metal frame and sqare section that will make a more permanent compressor, and this one should be able to handle a lot more pressure. But the odd jobs keep mounting and there is no telling when that will get done, let alone the tuning of my other springers and the Weihrauch HW35 most definitely needs a good check up as it's not as accurate as it used to be.

Just needs a few finishing touches

Two Breakbarrels, Big and Small

 Today I shall take a look at two break barrels, and see the odd bits of repair that have been done to them to get them up and running. Both guns are classics in their own right and deserve a little TLC at least, so here is what has been done so far to the Original Mod 16, and BSA Mercury mk11.

Diana/Mod 16 with BSA Mercury and scope

Firstly I picked up the Mod 16 which was looking in fair condition, but alas when i cocked, loaded a pellet and fired it, the pellet did not move more than two inches down the barrel. The Mod 16 is a small rifle made from pressed steel with a brass smooth bore inner barrel. It has a leather piston seal and a large leather breach seal on the cylinder which runs flush with the inner barrel and the large outer barrel - the outer barrel is a a tad smaller in diameter than the piston cylinder. The cocking linkage is pressed steel with a notch that locks onto a pin under the cylinder, you can cock it with one finger once unlatched. Cosmetically it just needs a paint job as the wooden stock is in pretty good nick.

Mod 16 breach and sight
Large leather breach seal on barrel and liner
Barrel catch is the loop piston lever

To get it working I popped a few drops of synthetic oil on the breach seal to rejuvinate it, and a little bit more of the same down the transfer port to put some life back into the piston seal. I then stored it barrel up for 18 hours to let the oil soak into the leather, and sure enough it fired just fine after that. I was getting 1 1/2 inch groups at 10 yards with the simple open sights, but I knew it should do a lot better than this. This is a junior rifle and is working just dandy at at the moment, but it does need a new spring and piston seal really. I reckon I can get away with soaking the leather in WD/40 then oil to bring it back to its former glory.

Tis a dinky lil' rifle, and pooch
Mod 16 shoulder stock
Pressed steel trigger
Whole barrel presses onto leather breach seal

Getting on to the BSA Mercury ... I find an air rifle that looks in a tidy condition, the bluing is fine and the stock just has a few surface dinks on it. The Airsporter is basically the underlever version of the Mercury and has the same trigger unit that creates a flowing curve from the piston cylinder to the stock, which makes for a a rather sexy looking air rifle in my mind. However, at one point someone has pulled the trigger while the rifle was cocked open, resulting in a very noticeable bend in the barrel at the breech. Also the rifle has had the open sights removed at some time, the jaws holding the breech are slack so the barrel moves from side to side a little, and the original spring has been taken out and replaced by one from a SMK B2. Why? I don't know, but it's sure easy to cock and probably produces about 8 ft/lb if it's in a good mood.

Smooth flowing lines of a Mercury
Ventilated rubber shoulder pad

So the first thing i did was to remove the stock, then tapping out the pivot pin i removed the barrel from the action. Clamping the breech end in a vice putting pieces of leather between the vice jaws and barrel to protect it, i used a piece of pipe slipped over the barrel till it came just short of the bend then pushed like mad till the barrel looked straight. Metal used to make gun barrels needs to be fairly soft, so it wasn't that hard a job to do. Using a long metal rule i held it flush to the barrel to see if any fine adjustments were needed, of which two or three were needed but the barrel was now true.

Straightened out barrel
Breach seal still in good nick

For fixing the barrel side play i used dial calipers to check if the jaws were out of alignment, and sure enough they were. By using the 90 degree angle on the end of a small rule i found out which jaw was bent, and again i used the vice to remedy this. By placing a 5 mm piece of metal at the end of the bent jaw i close the vice around both jaws and the end of the piston cylinder, on releasing the vice the jaw sprung back but only so far as to make a tight fit for the breech. Whoopee! Problem solved.

Articulated linkage on piston rod
I then slapped a Crosman 4x20 scope on it and it fired on target no problem, the only problem is that the scope is rather short and i have to crane my neck to use it, and the magnification is more like x2. With a lot of older BSA's in .22 the bore is a tad wider than most other .22's, so i found that using Eley Wasp no2 pellets work the best as they are 5.6 mm as opposed to 5.5 mm.

Cheap Crosman scope soon to be removed when i get something better

Some time soon i will get to sevicing and tuning the springers, but for now they seem to be doing fine. It's all down to when i can afford to buy the spares and springs for them, so it looks like i'll be doing a fair bit of busking to finance this air gun habit of mine.

Trigger guard needs a spot of paint i think


Salutations, Wing Commander Sir Nigel Tetlington-Smythe O.B.E.

Friday, 29 March 2013

Goodbye Norica Quick

Yep, it sure is a Norica

A friend of ours was looking for an air rifle recently, so the wifey tells him, "Oh, his Lordship has a load of them, I'm sure he'll have one that you might want". So after a bit of Facebook chat he wants one for hunting and out of the .177 Norica Quick, the .22 BSA Meteor, and the .22 Relum Tornado, he decides on the Norica. Which is just as well as the other two need a lot more tidying up before i would let them go to a friend, and besides it's knocking out H&N field trophies at 11.5 ft/lb and there would be no way in hell i would be able to get the other two above 10 ft/lb with out short stroking the piston or some other drastic measure.

Norica looking sexy with it's new scope, and unpainted new underlever catch

In the previous blog on the Norica i told you the under lever catch was missing, it was held on by two M3 screws and had temporarily screwed a turned round of aluminium with an indent for the ball to catch. Around that was a sleeve of tubing to slide over the tip of the lever so the lever would not pop off when it was fired, i was only using one screw so it moved a bit then fell off eventually. A total bodge job if truth be told, but it was only a make shift measure. Now it has a piece of round steel held on by two screws with loctite to secure them, an indent for the ball catch, and the sleeve of round pipe to hide the screw holes. The lever holds perfectly, and i painted it black to match the dark bluing of the barrel and lever. Spare parts are impossible to find in the UK, not even Chambers Gun Spares have any thing but a decent exploded diagram, which is pretty handy for dismantling, lubing, and repairs. A spot of Locktite fixed the the split on the rubber buttpad, 'simples (squeek)'

As it used to look with no scope and the old bodged catch

It was suggested that our friend buy a scope and have it sent to me so i could mount it, add shims if needed, and sight it in. I recommended a 3-9x40 or 50 as the larger objective lense lets in more light and gives you a bigger field of view, an illuminated recticle as he would most definatly be hunting at dusk, night, and dawn, and adjustable objective would be a handy thing to have though not the end of the world with out it. I suggested Nikko Sterling, Hawke, and AGS as pretty good value scopes, and i must of mentioned the Nikko Sterling Mountmaster AO IR 3-9x50 because that's what the postman delivered a week later. An excellent winning bid on Ebay, boxed and most likely used once if at all, lucky bugger.
Nikko Sterling Mountmaster with Hawke high mounts

It tells you all you need to know in one spot, very handy indeed
The scope has mil dots and red and green adjustable IR, personally i perfer duplex crosshairs or 30 30 crosshairs but i found these mil dots a good second choice as they were very fine and didn't completely cover the bullseye at 27 yards. I did have to use four shims from an aluminium can on the rear mount to keep the vertical adjustment turret knob central, i find if any adjustment knobs are dialed most of the way out the erector tube holding the recticle can move when springer fires. The spring on the other side of the turret knob is to loose and the erector tube will move slightly on each shot and change your point of impact (POI), there is enough slaming around on each shot to make your scope slide off the rails. So those clever little Spanish airgun designers put a scope stop that screws on the rear of the piston cylinder, this is just as well as the open rear sights have a minute bit of side to side play. Which is no biggey when your shooting tin cans at 30 yards , but just don't make the grade when you want a clean kill on a bunny scratching his butt at 30 yards.

Just to show the clarity, it was not mounted so the ferrets were safe
Nice fine mil dots unlike some cheap scopes

The trigger pull is very heavy, in fact so heavy that it effects the accuracy to a degree, the trigger is a direct sear trigger which means that trigger and seal are one piece. So it looks like i will be giving it a tune and a looksee at what i can do about lightening the trigger pull, i reckon it will still be stiff but not as bad as it is now. Roll on another blog then.

A closer look at how sexy gun and scope look together


Happy Days, Wing Commander Sir Nigel Tetlington-Smythe

Friday, 8 March 2013

Two Underlevers, Old And New

Relum Tornado above and Norica Quick below

Today I will have a look at two Underlevers, namely the Relum Tornado in .22, and the Norica Quick in .177.

Relum Tornado with slimmed down stock

First we have the Relum, which is in need of more metal restoration than I first thought, as the metal is slightly pitted with rust and 95% of the paint is missing. But when I rubbed it down with some really fine grade wire wool and oil it cleaned up quite nicely. I really need some rougher grade wire wool to remove the rest of the enamel then it could be painted, enamelled or blued, ooh! I'm spoilt for choice. The stock is interesting as only the fore grip is original, the rest has been slimmed down to come flush with the cylinder, and wood added to change the shape of the butt and grip. I have never seen a stock like this on a Relum before so I assume it's a home project, and I have seen a lot of Relums. I mean, you could buy them from the Co-op in the 60's and 70's, yes really! It may not be everyone's cup of tea but I like how it looks and it balances nicely at the foregrip, though that aluminium muzzle break and hood will have to go for sure.

Hole for scope stop.   Slimmed down stock.  Reshaped stock with wood added to comb and grip.  Hole in rear sight

The Tornado is about 7lbs in wieght without a scope, and about 40 inches long. It has the look of a long rifle about it and that is what appeals to me. This air rifle is going to need to have a lot of time invested in it to get it looking good and get it up for hunting - other people have reported thet they have got up to 11 ft/lbs but we shall have to wait and see.

serial number

All Relums have pretty much the same leather seal piston assembly and a double spring set up, which is a smaller diameter spring inside of a larger one, instead of a guide rod. This double spring can be replaced by a BSA Meteor spring, but it would be wise to have a guide rod made up to support this. They have a simple sturdy Eastern European build quality as they were made in Hungary, but have never been capable of more than 8/9 ft/lb. This I reckon could be improved upon by changing the piston head to seal with two O-rings and giving it a slightly longer piston stroke, which hopefully should not alter their light firing cycle much.

Another common feature on these air rifles are the rudimentary open sights. The rear sight is held in place by a dovetail and adjusts the elevation, whilst the front sight adjusts for windage by sliding it across its dovetail. This was originally covered by a simple hood. Pellets are loaded via a tap mechanism which still feels nice and tight, and the bore is the same as modern .22, unlike some older air rifles and pistols which are a tad larger. The BSA Mercury has this larger sized bore which is 5.6 mm instead of 5.5 mm, you can buy Wasp no2 pellets for the larger bore size. Interesting fact: did you know Relum is Muler spelt backwards, which is the surname of the owner of the factory!

Hole for scope stop (off center).  Loading tap.  Inlaid wood.  Rust removed with some oil and very fine wire wool 

Well, why won't this air rifle cock? I'll tell you why. When I removed the stock I found the sear pin was missing. This was replaced by grinding the base of a broken drill bit of the right diameter to size. Now it cocks and fires, but the piston seal and spring need looking at as it's nowhere near 8/9 ft/lb. The rear sight is a small hole through which you have to center the front sight (as opposed to a notch), this is not reliably accurate, so gluing some crosshairs made from a strand of copper electrical wire will improve this no end. There is a small hole at the rear of the scope rail which could be used for a scope stop if it ever needs one, however I suspect, along with the stock, that this has been added afterwards and was not produced this way. I reckon this air rifle will be fun to restore, and I have spares from the Relum Telly if they are needed. I could always use the Telly's barrel for another project I have in mind, so nothing is wasted.

Norica Quick and it's favourite pellets

The Norica Quick appears to be in tip top condition, apart from missing a small piece of metal that holds the cocking lever in place. There are two M3 holes on the underside of the barrel to hold it in place, so turning and drilling a replacement would be the thing to do until i can find the original part. However a search on the internet has turned up very little useful information and spares, I think this air rifle only had a short production run from its Spanish creators. You can find this same rifle bearing the name Hammerelli Nova which also returns very little information on the internet, so this one should be fun to work on.

Bodged underlever catch

 The Quick at first glance looks a little like a top quality under lever, but truth be told it is really mutton dressed as lamb. It was actually made in Germany for the Norica company. The stock is a nicely lacquered beech with chequering on the grip and forestock, the butt has a raised comb for the right handed shooter and a soft rubber butt pad which needs a spot of glue. The end cap is plastic as well as the chunky trigger guard, the front and rear sights are mainly metal with fibre optic and this is missing on the front. The trigger blade is stamped steel and the action and barrel are blued to a black finish, while the flip up loading breech which is vagly similar to the HW57 design is plainly plastic. This is a large air rifle at 46 inches long and is about 8 lbs in weight. It is full UK power to boot, action and stock fit snuggly together and is comfortable to hold.

                                         anti-beartrap on the Norica Quick

Loading and firing is a little long winded, but once you get used to it is fine. The plastic flip up breech is long, giving you plenty of space to load. It locks in place with a spring loaded knob on the right and hinges over on the left, this seals well but gives it a rather long transfer port. The cocking arm is heavy at 56 lbs and is hollow so has bent a little over the years. The trigger is really heavy and you have to hold the grip firmly to squeeze, this will obviously affect the accuracy somewhat and will also need looking at. But truth be told it's a good priced lower-mid range underlever that performs as well as it costs, and gives the appearance of a quality German air rifle.

Flip-up loading breach and dayglo open rear sight

At first loading a pellet, cocking the rifle, turning of the anti bear trap, then removing the safty in the trigger guard was a bit of a chore after firing break barrels, but it did not take long to become second nature. Improving the front open sight or fitting a scope will improve accuracy no end out to 30 yards, but will only help so much until I can improve the trigger pull. There is a slight buzz upon firing which Moly and spring grease should sort out and improve lock time, removing the anti bear trap and greasing the cocking linkage should make it a much quieter rifle, and Chambers supplies a decent exploded diagram to make the job a lot easier.

So there you have it, TTFN

Best Wishes, Wing Commander Sir Nigel Tetlington-Smythe O.B.E.