Old HW50S

[Quadra]

I recently purchased a 1972 DOM HW50S. Upon arrival I tried a few weights of quality pellets through my chronograph. JSB exact 8.44 gr averaged 570 FPS and Exact 7.3 gr came in at 615.Both were 10 shot average.These figures are low so I ordered a spring and guide kit from ARH designed for the R8 HW50S. In the description of the kit there was mention of varying piston lengths. Would someone versed in older Weihrauch HW50 air rifles explain that to me please. I am unfamiliar with the internals of these airguns aside from the 25mm piston diameter and that it will be a leather piston sea.

[Mach 1.5]

The old HW50S are 25mm. The new version HW99 and in Europe the HW50 are 26mm. The old HW50 is a different beast to the modern thing and in my opinion a far better rifle. It appears you may have ordered a kit for the new version and not the classic HW50. T20 will be along shortly to help with more tech spec. Mach 1.5

[Quadra]

The kit specifically states it is for the Beeman R8 Hw50S, not the current HW50S/HW99

[Mach 1.5]

Interesting. Beeman was sold off in 2009. So unless the new kits are to a different spec then I'm not sure. Sorry I couldn't be of more help. Mach 1.5

[landymick]

The R8 is the later version of the MK1 HW50S ,still on 25mm internals but uses a synthetic seal . This later model had higher power than its predecessor running around 700 fps in .177 .

[Mach 1.5]

Maybe the leather seal needs attention? Mach 1.5

[landymick]

If it’s getting around the 600 fps velocity it’s about right for a standard leather seal MK1 50 .

[deejayuu]

They may be referring to the slight difference in piston rod/stroke dimensions of 50 and 55 versions. Just a thought.
P.S. got photos somewhere if it helps.

[MDriskill]

Jim Maccari at ARH ("Air Rifle Headquarters") absolutely knows his stuff. He's a big fan of older airguns, and the kit you mentioned is the correct one for the "real" original HW 50. I've installed several of his HW 50 and HW 55 kits and have been very pleased.

On the piston length issue, it's my understanding it's not the overall length of the piston per se, but the length of its solid front section, that the piston seal threads into. This affects how much space is available for the spring - many years ago I put one of his kits into an HW 50 with a "long" piston - it coil-bound the spring before the sear could engage. Jim has long since modified the kits to work with even the "longest" piston. If your piston is a "short" one, it will still work fine out of the box, but you may be able to add a spacer to get a bit more compression.

[wil95k]

I have an old Hw50 and a new 50,I'll put some pics up of the pistons/dimensions for you tomorrow.

[Quadra]

thank you for the replies gentlemen, I'm eagerly awaiting the package. I thoroughly enjoy tinkering and learning something new.

[T 20]

. T20 will be along shortly to help with more tech spec. Mach 1.5

Unfortunately, Paul.

The 3 HW50s I've worked on have all been synthetic sealed guns with a 65mm stroke so I couldn't really add anything, my fourth 50 maybe leather sealed but it's running so nicely that I don't want to open her up.

The HW35 leather sealed piston and synthetic sealed piston have different length piston heads and Spring room so I'm happy to accept MDriskill's explanation which makes perfect sense.

My playing with Oldschool 50s --- https://www.airgunbbs.com/showthread...highlight=HW50



All the best Mick

[duomatic410]

Have the HW 50 in 22, it must be an early one as no safety and not Record trigger.
It's very weak in power but a pleasure to shoot.
It's got nylon seals.
Shoots spot on, can't be bothered to change springs to up it as have others available that are 11 plus.
It's lighter than the 35s, and a lot lighter than the 80 mk1👍

[T 20]

Have the HW 50 in 22, it must be an early one as no safety and not Record trigger.
It's very weak in power but a pleasure to shoot.
It's got nylon seals.
Shoots spot on, can't be bothered to change springs to up it as have others available that are 11 plus.
It's lighter than the 35s, and a lot lighter than the 80 mk1��

There are two different HW50 --- the HW50M has the Perfect trigger and the HW50s has the Rekord trigger.
The differences are shown in the Airgun book by John Walter :-

image.jpg


So the trigger fitted appears to be no indication of age, --- it's better to work off the serial number.

Also, all 25mm Weihrauchs changed to synthetic seals in 1983 so if yours has the original piston it could be younger than you think.




All the best Mick

[duomatic410]

Thanks for that Mick, 50M it is, no safety catch on this one of any type.
Trigger not Record but quite good. 👍 John