Tesro RS 100 Eco

TESRO was founded in April 2002 by Peter Römer and his son Daniel. Peter worked at Walther as designer (I believe he was involved in the design of the LG 300) and then became a general manager. His son, a graduate in applied science, joined him and together they developed the Tesro Range of rifles and pistols.

They first developed and released the PA10 air pistol, things moved swiftly and the sport-pistol was released in the early 2003 followed by the air rifle in 2004. The rifles are based around the RS100 action – Basic, Eco and Pro versions being available with an increasing number of features. They also deliver the same action in “auflage” style stock that is made for the German standing shooting from a rest. A junior version is also available.
 
First Impressions

The Tesro RS 100 Eco was supplied in a lockable, foam-lined hard case! The first impression is one of quality. Finish is excellent with satin aluminium for the main stock components and barrel shroud, blue and grey laminate for the grip, cheekpiece, forend and contrasting black action, muzzle weight and cylinder. A tool kit, charging adapter, cylinder discharge screw and a 4.0mm plastic sight insert are supplied to get you going. You can have the Eco in a black finished stock if you find that more appealing.

The aluminium stock allows a greater degree of flexibility over their wooden counterparts and the RS 100 makes full use of this. The forend can be moved forwards and backwards and has spacers (two provided) to alter depth. The butt-plate has a fixed profile and can be adjusted vertically and angled laterally. Likewise the cheekpiece along with the provision for being moved backwards and forwards. A balance weight can be added to the rear of the cheekpiece. The vertical adjustment has a scale to assist control. The stock length is altered by loosening a single bolt and sliding in and out. The butt-plate mounting also carries a bar to add further weights if desired. The pistol grip can be moved forward and backwards and swung side to side but not rotated about its vertical axis.

So what’s missing on the Eco from the Pro version? Well the butt-plate on the Pro has an adjustable profile and more offset and angle adjustments and can be angled down and upwards. The Pro cheekpiece can be rolled over as can the forend and the grip can be rotated. Practically speaking there’s plenty of adjustment!

Charging the Cylinder

The cylinder is unscrewed from the rifle for filling, a DIN adapter is provided. The system allows either 200 or 300 bar filling. A full charge of 300 bar will give enough air for about 400-shots. The fill indicator on the end of the cylinder is, as ever, very useful as a quick check before shooting allows you to forget worries about the state of the charge. A screw is provided to allow discharge of the cylinders if you need to discharge them for whatever reason.

The 20mm diameter stainless outer tube houses a 16.5” barrel which I believe is Lothar-Walther in origin. It shows the familiar extension tube arrangement as on most 10m rifles – to optimise length but maintain the sight radius. This feature can be adjusted by moving the barrel weight/foresight from 650mm out to the ISSF maximum 850mm.

Operation is by a side lever and cocking effort is minimal. It utilises a hollow, probe-type bolt which pushes the pellet into the breech but, when fired, delivers the air into the centre of the rear of the pellet. This aids in it starting in the best possible conditions. A dry fire button is provided which intercepts the hammer on its forward stroke.

The barrel is supported at the breech and also at the front of the stock – good if you are in the habit of resting the muzzle during loading.

Sights

The Tesro features the now familiar, back-lash-free, tube-type rear sight and 18mm front unit. The latter is mounted on the barrel weight. This useful feature means that you can make minor adjustments to suit your preference within the 850mm overall mechanism length. The neat thing is that they are both adjustable for cant. The rear can have the adjustments vertical no matter how much cant you use and the front bar levelled to control the cant.

The eyepiece is threaded to take the standard iris/filter attachments available for Centra, Gehmann et al. The foresight appears to take standard Anschütz 18mm accessories and elements. The literature provided with the rifle says each click is around 1.2mm at the target end – I didn’t notice anything unusual - the normal handful of clicks had the desired effect.

Outwardly the trigger looks Waltherish! It has all the standard adjustments for weight of first and second stage and travel of both first and second stage. You can attack the sear engagement if you wish – however, the release point was crisp and consistent so I left it. All adjustments are fine and easy to access and crucially independent! There’s nothing worse than altering say, first stage travel, and it changes all the rest of the settings. However with the factory setting the trigger released at a pleasant 110 grams – everyone who tried it commented how crisp and consistent it was – never the less I doubt many will stay un-adjusted!

The blade can be mounted on either of two parallel rails and is adjustable for position fore and aft, side to side, up and down and can be turned on the stem. This means you can literally place it anywhere in the guard so no compromises here. The blade has an O-ring which can be placed in different grooves to allow consistent finger placement.

Accuracy

Testing was from the machine rest at 10 yards. 5-shot groups were fired with a variety of pellets.

The best muzzle velocity readings over 10 shots were with H and N Finale Match (4.49mm) with an average velocity of 538fps and an extreme spread of 12fps.

The rifle is clearly accurate and the spread of the velocity provided by the regulator is good to the extent of being unnoticeable on a target at 10m.

The near perfect one pellet wide test group supplied with the rifle was shot with 4.49mm pellets as well, which confirmed my tests. The Tesro was not particularly sensitive to pellet type but had a preference (albeit small) for 4.49mm head size. The best I could get was 5.2mm outside edges with the ammunition I used.

Prior to shooting from the shoulder the rifle was easy to get a basic set up and although it doesn’t have all the adjustments of its “Pro” cousin! I would be soon investing in a set of sight raising blocks but apart from that it was very easy to get going. The literature doesn’t mention any compensator system but there was no apparent recoil or pulse on firing, evidence of a well-balanced regulator and air delivery system. The velocity at just under 540 fps is sensible and generally removes muzzle flip issues; do you really need more speed? Methinks the only thing you will notice at 540 fps, as compared to 580 fps, is the smooth shot development at the lower figure.

The rifle was a pleasure to shoot with a quick action and good trigger – what’s more it was easy to set up for others to use with adjustments that are easy to get at and largely independent of each other. This makes its intrinsic accuracy easy to deliver. The dry fire system is always useful for practice.

Conclusions

The Tesro RS100 Eco offers good build quality, accuracy, a useful range of adjustments and a superior trigger. The standard of finish is excellent and if you are in the market for a 10m air rifle it is definitely worth a look. It’s nice to see something new on the block – particularly when it turns out to be this good. Let’s face it; 10m target air rifle has got to be a nightmare of a market to break into. Ultimate accuracy and quality are expected as the norm but it looks like they have the pricing structure right and I think they will do very well. There is a market for a good quality, competitive rifle with a practical range of stock adjustments at a reasonable cost and the Tesro RS100 Eco is in that bracket.

Tesro also manufacture pistols (air and .22) and a very interesting range of .22RF rifles and stocks. Word is on the street they are looking into the feasibility of a 12ft/lbs FT version of the RS100 which would be a very interesting prospect for FT and HFT. Thanks go to Dave Mills for the loan of the test rifle.