BSA Mercury, Friction in the Piston

And Finding The Most Accurate Pellet For a 70's British Springer

Out in the woods testing the .22 BSA Mercury.

I have done a far bit of tinkering with the .22 mercury, but i know it needs a little more. It's knocking out RWS Superdome's at 10.5 ft/lb then slowly dropping down to 9 ft/lb, this i'm sure is down to the tight fit of the rubber O ring piston seal. 

The new piston seal O ring below is a bit over sized.

 I've read that it's a common problem that the piston seal can be a little oversized when new, and i did have to use some force to push the piston into the compression chamber with this one. Most people usually put a tin of pellets through to wear the piston seal down, but i reckon in this case i would need nearer two tins of pellets before any wear is noticed on the O ring.

Repeatedly putting a 1000 pellets through the Mercury would get a little tedious to say the least.

My other option would be to dismantle the rifle yet again, and use wet and dry to wear the O ring down, i would need to turn the piston in the lathe and apply the abrasive to give it even wear, 

It doesn't look over sized when fitted on the piston head , but believe me it is.

Then i would size the piston now and again till it was just short of a sliding fit, so once the ruff edge of the seal had smoothed out after reassembly it would fit perfectly. 

I would rather avoid going through this rigmarole again.

My only concern for the rifle is for the thread on the breech block getting damaged with all this taking apart and reassembly, i also have a concern for the spring compressor because of the mighty preload.

These were good value and sorts out the problem of the scope rail dovetails being set too forward on the compression tube of the Mercury.

A 1970's .22 BSA Mercury has a barrel that is 5.6 mm as opposed to 5.5 mm that is more prevelent now a days, and the older pellets that were a tad wider are not available any more. Eley Wasps in the blue tin are sized at 5.6 mm but are crap compared to how they used to be, 

No 2 5.6 mm Eley Wasps are not the pellet they used to be.

i have found that RWS Superdomes fit just as well in the breech and are infinetly more accurate. So with this in mind i reckon it would be best to see how the rifle performs after i put a tin of Superdomes through it, at 7 quid a tin it sounds like the fun option to me and i usually take a second rifle with me when i go down the woods.

Accuracy

   I have found the Mercury shoots most consistantly with a light hold and supported by my off hand just in front of the trigger guard, from personel experience most springers are more accurate for me if i support them at where they balance and this is where the Mercury balances out. The trigger breaks lightly and cleanly with no first stage travel so it's easier not to pull any shot of target, both my BSA Meteor and the Webley Hawk have similar triggers to this so i reckon it must be some British thang.

Ready for the off.

Testing the accuracy in the woods means i can't test from a bench rest, but the results will be more indicative of how it will perform in a hunting situation. The rifle was sighted for 28 yards and i will test at 15 yards and 30 yards, and with the shelter of the woods i don't have to worry about wind effecting the results.

Resting the rifle, uncocked and unloaded, while i go of to check the target.

Using the large cardboard boxes that were left over from Christmas presents as targets i took Scatterbone down to the woods and paced out 15 yards, 

Handy large cardboard box left over from Christmas, inside is foam packing and a piece of ply wood, after a few tests i can stick targets to it with the Gaffer tape i always carry around with me. As i say," If counceling won't fix it, Gaffer tape will."

i shot from a sitting position with my back against a tree while holding the rifle lightly with my off hand supported on my left knee. Out of AA Diabolo's, Falcon Accuracy Plus, Eley Wasp's, and RWS Superdomes, i found the Superdomes to be the most accurate in the 5.6 mm barrel of the Mercury. 

RWS Superdomes in any caliber are the best all rounder in my opinion.

At 15 yards 6 shots came inside the size of a two pence piece with the Falcon's coming a close second, the Eley Wasp's were all over the place thinking i had lost my mojo but then the the Superdomes did it again.

I'm pretty happy with these results, cleaning the barrel and perfecting my hold will improve results no end.

I tried to test the Mercury out to 30 yards but it was pretty windy even in the shelter of the woods, with the wind push the pellets two inches over to the left. I managed to do some shots compensating for the wind and managed to get on target, but as it was i was well chuffed with the results of the 15 yard shots. Having put just over half a tin of pellets through the Mercury since i last tinkered with it i have found the best hold for me, being happy with that i reckon i should just put an other couple of tins through it till it beds in and the velocity rises and settles down. I really would like to keep this air rifle as the surge and recoil are quite mild and as a .22 it carries a lot of knock down power down the range, and above all it looks bloody sexy for an air rifle.

TTFN

Wing Commander Sir Nigel Tetlington-Smythe.   

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

TTFN

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

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.