Tesro RS100

[Jon]

Very very Walther, without taking measurements i would say the one piece action is same as the old LG200 from circa 1998, LG300 and LG400 with minimal differences.

Make no bones about it these are a right pain to take apart but once figured turn in to a pain.
Wondered why there was just one allen key in the tool kit, they should have provided a 3mm drift, hammer and pliers.

You want the bolt or hammer out, means taking two trigger sears out and rear adjuster, driving numerous roll pins out that have to line up with another part. The shear amount of parts you will have lying around i would say 80% of tinkerers would give up.

Reg is the same as a Mick Dawes from 1983 which have been making since 1992 and in current Walthers, Anchutz, BSA, and many more. Difference here is the piston runs in the main action rather than a bolt on arrangement.
What i did notice is a Steyr reg could bolt directly on but would need to block off where original reg piston sits and create a seal on front of action off the Steyr reg. Easier to make a new one.

Another difference is the knock open valve arrangement held in by the front of the reg rather than screwed in.

Cocking is side lever interchangeable left or right hand. Half rifle has to come apart to change over including trigger sears and adjusters. You have to line a hidden pin up in bolt manouver with hole in top dovetail, line hammer up all in line and drive a pin down in to trigger area. Thats why trigger has to come out. To get the hammer out that pin has to come out deep inside action with very little room and two pairs of hands.
Trigger is exactly Walther mechanically.

The low down on this should anything ever fail, its you out of action unless happen to have a work area then a couple of hours to spare. Walther LG200 to 400 series are s a 5 min job most things.
Theres roll pins every where and fear some will work loose. In fact apart from 4 screws to bolt reg on and hold knock open valve in, barrel and cocking pivot, thats all the screws there are apart from adjusters.

Safety is a push button rather than a rocker as on Walthers.

Pressure tube is labelled Tesro and working pressure 300bar. Its M28 X 1.5mm threads over 11.3mm length with 2mm clearance at end of male thread.
First things first a new end plug with quick fill and dust cap.

Good news and about the only good news is this is the first German rifle thats bedded in right in the aluminium mechano bolt together stock.

[Delphinus]

Jon,

How the Tesro barrel performs, it’s like in the FWB or take more wind?

[Jon]

No idea havent even fired a shot through it yet, just had a look at how it could be done.

[MarcKA]

The Guy behind Tesro seems to be an old Walther Designer, so we should see quite some Similarities here.. I also once have heard that he'd be quite happy to build 12fpe Versions right from the Factory, if Demand is high enough.

Could you post up some Pics Jon?

[Jon]

Me and piccies

Thought he was ex Walther, another one who didnt reply back in 2005 so went else where to a company that did ie Anchutz.

[Jon]

Hot off the press the first 12ft/lb conversion in the world, certainly not doing another.

They are really awkward to do with the bolt on internal reg which rules out threading regs direct to action. Add to this theres as much work in just doing that than a full on power conversion for a P800. Then add on a purpose designed and made reg with extension all screw cut together, you can just see one joint where I have put a 45 degree angle the rest is wasted space in the adaption to action remaining safe.

I could have easily have hidden the reg inside the cylinder giving a shorter overall length. Main reason didn't know what to expect and needed something I could quickly adjust, hence being able to remove cylinder leaving air inside. Got it off to a fine art adjusting reg pressure can do it in 3 mins back on rifle. Once set will be locked down.

Even then couldn't get the power hit a limit of 750ft/sec so machined up a reliable CZ barrel and had to back off 40ft/sec. CZ barrel also fits inside the original Tesro sleeve which will look better ending flush with dust cap.

Like the Walthers these are awkward to machine and fit correctly. By that you wont just bore the feed in it has to be matched so transfer port lines up whilst bolt creating a seal without touching the bolt taper in front and behind the o thin ring.

Don't get me wrong you could reasonably easily machine the taper in the barrel but it wont align with transfer port, only one solution sand it in and lots of trial and error. If you were doing a fair few easier to make a tool up but that will leave marks in the tapered feed.

Replacement end plug with quick fill and dust cap on to the Tesro aluminium cylinder.

Differences over the ancient Walther blocks ie LG200/LG300/LG400 is side lever cocking, thinner block think its 19mm, safety button, and that dreaded left full where Walthers reg extension sits strengthening it up. The Walthers here flex 3 dimentionally even with some aftermarket rails, the Tesro wont even without.

The new AA FTP thingy has a front A frame fixed off the action, the Tesro already has it and guarantee zero shift.

Luckily there is a hole in stock on underside usually where the Walthers should be only fixed to. Do away with A frame with reat two screws and bed in on that underside stock fixing hole, free floating guaranteed to work. Rest assured that will be done with that FTP thingy.

As is it shoots better than 99% of Walthers, its no Anchutz 8001, 8002, 9003, Steyr lg100 on or Feinwerkbau P800.

I don't know if the Walther cylinders will screw on to a Tesro but if they did it would be cheaper and easier to buy a Walther reg no extension and have an adaptor and reg extension made. From memory think the Walther regs are close on 35mm diameter, max you can go on Tesro is 32.5mm but an easy job to turn down.

Steyr regs look like they will bolt on to the action having a pretty close 4 bolt fixing to the Tesro but in same no win scenario need to create volume and blank off where reg sits in action. To do it right will lose volume and add extra unwanted length much like the P800.

[AdminMASTER]

Congrats Jon !

Another World's FIRST power mod. !

...like everyone, just wondering how good that CZ barrel and the whole package shoots..

[Jon]

Certainly wont shoot as bad as the majority of Walthers.

First class trigger on it same as LG200.
Its very light until I put the muzzle weight on.

[AdminMASTER]

I fancy another power modded 16J Tesro RS100 - with a different alu stock. & blue laminate parts

Mmm...wondering if Jon can do this one as well ?

[Jon]

Funny enough the other week had a blue cheek raiser anodised similar colour.