[Sticky] Hämmerli sidelever spring sporter air rifles

Hämmerli sidelever spring sporter air rifles 

With thanks to Alistair for this information. 

The Model 4 had the underbarrel weight, and a micro-adjustable rearsight, while the Model 3 I have has a crudely adjustable notch. They are very similar to the 400 series, with the exception that the Model 4 barrel inserts above the centre-line of the compression chamber, while the 400 series has it centrally. The 400 series includes the 401 (micro-adjustable open sights), the 402 (no ironsights), the target version 403 and the 420 Military trainer.

They were sold with the underbarrel weight as target rifles, but can be used (at less than 30m) as sporting rifles, the power being about 8 ft/lbs.

They have very nice triggers, on a par with the Anschutz 335 and nearly as nice as the Weihrauch Rekord unit, although not as robust.

Recently the BBS yielded that some of these Model 4s (there was a Model 3 and a Model 10 which are nearly identicle) have trigger units which lack the sidelever safety anti-beartrap mechanism.

They are extremely sweet-shooting and extremely accurate, the trigger being very smooth and precises owing to its long levers, and also the barrels are some of the best ever fitted to a spring powered air-rifle. They are also some of the only recoilling tap-loaders that are actually MORE accurate than most of the top-quality break-barrels of the time.

The main weaknesses are the tiny allen-headed bolts holding the trigger unit on, which must be kept tight, but not so thight that they shear. If the trigger unit gets a little loose, the stamped steel sear will wear out. The side-leaver can start to bend near the hinge, so be gentle when cocking it and don't 'slam' it open. The strange ball-and-V-spring sidelever catch has worn out on my Model 3 and I am replacing it with a brass catch from Robert Dyas, like one would use on a small cupboard.

The mainsprings are still available from Chambers, although I heard that a HW77 spring will fit; this might get a little more power out of it. The mainspring is possibly the longest spring ever fitted to a rifle, at about 15" before fitting. The spring guides are very tight on the spring, and the rifle discharges very suddenly and without any twang.

Hammerli ought to have developed this rifle but must have decided to concentrate on pistols and firearms, and the design hevily influenced the Sussex Armoury Jackal range, the company which eventually became Air Arms.

Do a search on Hammerli, there is a bit of other info about.

Keep the rifle, they are nice shooters, simple and spares can be made up by any competent engineer. One thing to note is that they have wide 13mm scope grooves, which means you have to get some from an old Weihrauch or get some modified to fit.

These knowledgeable internet posters provide more information:

TheHammerli420 military-style rifle was produced in the mid 1970s before the Sussex Armoury Jackal.Hammerliis a Swiss company, although I think the factory was in West Germany at this point. Some say that the Jackal is a larger, beefier copy of the design and that some of the early Jackal barrels were made in theHammerlifactory. It is aHammerli400 target/sporting rifle in an assault-style stock, not sure why this target gun company decided to make one. Perhaps for the Swiss market? they have a citizen's army so are obliged to practise shooting their G3s and it might be something they could use at home in their gardens/fallout shelters! Anyway, it was reviewed twice in AGW and always did extremely well in the accuracy section, although it wasn't very powerful, about 9 ft/lbs tops. The mythical 'Fred Grimwade' in AGW was a great fan of the wood-stockedHammerli401 series in .177 as a HUNTING rifle, he valued accuracy over power and was the first person in the UK to 'come out' and say that .177 was superior to .22 for hunting.

Internally, the 400 series has an extremely long spring (you really need a spring compressor) which is under a great deal of pre-load and which has a long, tightly-fitting spring guide. This gives a very sweet firing cycle and very little recoil or vibration. The chamber does not have a large swept volume, so there is not much room for improving power, but the transfer port and loading tap have little 'dead space' so they are very efficient. According toHammerlilegend, there is a tight choke on the barrel which contributes to its superb accuracy and relative lack of pellet sensitivity. DON'T 'carbine' this rifle, you will lose its excellent accuracy.

The trigger is sweet as they come, although the stamped parts cause the problem of wear if the trigger mounting bolts are not done up tight. It's mechanism employs very long levers which allow a light and crisp action.

The lack of sear engagement is quite common. The trigger unit is held onto the compression cylinder by six or eight tiny allen screws (too small in my opinion) and if these are not tightened up properly then the sear will not engage, or it will only partially engage and then wear the tip of the sear off. The sear itself is a small flat piece of tempered stamped steel with an angle on it, if it is worn out any competent engineer or gunsmith could make one up in 20 minutes for you. The screws holding the trigger unit on should be carefully screwed in, first just finger-tight and then finally with an allen key, doing them in sequence so the pressure is spread evenly, just like when you are fitting a cylinder head on a car engine.

The rifle should have an anti-beartrap mechanism which is quite noisy, you can press down a lever which juts up near the cocking slot and ease the spring down if you need to de-cock, but be careful or you will chop your finger tip off!

The strange drum-style loading tap, with its knurled round knob annoys some people but I soon got used to the one on my 401 and could open it very easily with the left thumb by applying a sort of rolling pressure. Once I got practised I could load and fire it at the same speed as a break-barrel.

The open sights on these rifles comprise the quite nice interchangeable tunnel foresight from theHammerli401, which is held on by a bolt squeezing the unit on the muzzle, plus the non-windage-adjustable rearsight from theHammerliModel 3. But to experience the great accuracy these guns exhibit you need to fit a scope. I seem to remember they have quite wide scope rails, 13mm, the mounts from the older Weihrauchs fitted well.

It's a really nice rifle and I think the only reason they didn't sell well is that they were not '11.9 ft/lbs' which is all anyone ever cared about in those days. There were probably about 100 sold in the UK, most of them with the swoopy stock like the one you are selling, also didn't have dummy magazines and were sometimes black in colour, sometimes green like yours. They are far better rifles than the Sussex Armoury Jackals which were larger British copies of theHammerli, but as the Jackals were very popular (11.9 ft/lbs!) they allowed Sussex Armouny/NSP Engineering/Air Arms to develop and eventually come up with the TX200 series. Of course the TX is Ken Turners 'perfected' HW77 and owes nothing to theHammerliin terms of design, but in spirit, the gun you have is the great-grandmother of the TX200!

You can still get mainsprings from Chambers, but other parts are not available. The piston seal is leather so you can make your own, but the design is very simple so you shouldn't need any other spare parts (other than the sear, which can be made up) really.

To answer your question, were they target or hunting, they are really both for the time that they were sold in. They were good hunters up to 35 yards, and they were the same power as most .177 hunter rifles anyway. The BSA Airsporter and Original 50 (which are comparable fixed-barrel hunting rifles of the time) both did about 9 ft/lbs tops in .177, only the BSF and Feinwerkbau rifles were really powerful in .177. Of course it is not a match rifle but it's superb for informal target shooting and plinking. Its a peach!

In relation to the model 40x:

Beware of how the trigger unit attaches to the cylinder. My 401's was attached by 4 M3 bolts (some say 6 but mine had 4). Trouble is the cylinder wall isn't very thick so there's not much for them to grip and it's easy to strip the threads. Consequently I found only one of them still gripped, the others having wrecked the threads were just sitting there. A highly dangerous situation, as it could have gone off by itself when cocked. The solution was to (a) not use it until I (b) got someone to tap them out to M4. Then you'll find that they like to be tightened up just so - too tight and they don't like it at all. The spring washers play an important role.