Walther LGR: a puffer paradise

[Phil Russell]

I admit to really enjoying bringing a non-working rifle back to life. But every now and then one throws me a googly that gets me wondering what's wrong ... me or the rifle. Such was the case yesterday and today for a Walther LGR. I knew it was not in working order, no compression at all. So new seals were ordered ... the piston seal and the valve seal. The piston seal apparently comes in two sizes according to the Knibbs site. I selected the size which matched the current (blue) seal on the piston and figured it would be OK. Parts were soon with me and what I thought would take at most a couple of hours began. No problems with the basic strip down but one of those two screws that have curved slots for the driver played up and I had to resort to much heat before it shifted. And yes, the curved slot suffered even though I had a good fitting driver. Never mind, I sorted it. The rest went swimmingly and I noticed with relief that the piston would slide much too freely in the cylinder and that the firing valve seal was the nature of cork. But then the piston seal bit ... jeepers that was difficult both to remove and replace. At one point I was thinking that the piston may have been an old one that had the bonded seal but I persevered to cut the old one away and was relieved to discover the slot for the new head to fit into. Fitting the head was an horrendous job but using hot water treatment, a vice and some timber and brute force and it finally clicked into place. Homeward run? Nope, another bite coming.
Re-assembly of the parts was pretty easy and it was with some trepidation I cocked the action and too the first shot. OK, good. Then tried a second shot but oh dear, trigger failed to engage a couple of times then did engage then did not. In the end I had the rifle out of the stock watching the bits as I cocked the action and fired. I could see nothing untoward but stripped parts down to make sure I had not gone wrong. Nope. Then I realised that the shot before the failed attempt to cock would somehow displace the end of the hammer mechanism from the two small prongs that fit around the trigger frame support, not a lot but enough to prevent cocking. Twiddling the hammer prong frame back into its correct position on the trigger frame resulted in perfect cocking. Why? I spent a long time looking and puzzling. In the end I looked at a parts diagram and noted a 'puffer seal' (Walther part 2184711, part 71 on their diagram) was missing on my LGR. It sits on the actual sliding hammer rod and must act as a buffer between the hammer spring assembly and the sliding hammer. I can only guess it had perished and disintegrated never to be seen again. I found a suitable O ring to fit and tried again. So far with many shots there has not been a failure to cock. Relief. Such a small thing to cause so much trouble.
But it seems as if I am back in business. Now all I need is a dioptre sight ....
I accept that my description of the parts involved could be a bit hazy. This is mainly because the mechanics are not like any other rifle I know .. I had not looked at an LGR before except to replace the two breech seals. But a look at the parts diagram will show all. What a pity I did not do that to start with ....

Cheers, Phil

[Mark D]

Well congratulations on persevering At least you accurately diagnosed the problem and got it working properly in the end.

[RobinC]

The puffer does disintegrate, it always used to be part of the seal kit. Even if it looks good, it should be changed with the seals

When you change the breach seals don't forget to "headspace" them by barrel adjustment, by setting up the action in a padded vice with the barrel vertical, slackening the barrel so its loose, with the breach closed, let the barrel weight settle, then a gentle nip tight of the barrel clamp screw, then a gentle tap on the barrel end with a soft mallet, the degree of tap is experience, then crank up the barrel really tight.
If the breach is too tight (tap too hard!) the breach springs open on firing, if too loose it leaks (test with tissue paper). Setting is a feel thing and can take a few attempts to get it perfect.

Have fun
Robin

[Phil Russell]

Hi Robin, many thanks for that information as I had no idea about it. I will look and see.
Now to the puffer again. Adding a pseudo puffer seal, in my case an O ring, certainly solved the issue with my LGR as the tendency for the hammer system prongs to jump out of alignment with the trigger frame prongs has not happened since I added the O ring. I can only think there was a spring recoil / twist operating on the hammer spring during firing that caused the prongs jumping.
But.... and here is the puzzle... I have since had an opportunity to look at another LGR that has no problems but the puffer seal is missing. I am still puzzling and beginning to doubt my diagnosis that the lack of a puffer was the cause of my issue ... but then adding a pseudo puffer cured it.
If anyone can explain I would be grateful.
Cheers, Phil

[RobinC]

Phil
My wife was a GB Walther LGR shooter back in the "day", and still has her pre production prototype LGR Junior that she used Internationally then, and we spent a lot of time at Ulm, and I learnt all the set up routines used by the factory techs. Although I did reseal hers a few years back I can't remember the full details.
I think the puffer is primarily to seal not support, but it does serve as a bearing as well, with out it I suspect the sear does not set correctly, need to have a good look at the drawing, its on the Walther site, media, then breakdown drawings.

Now dear old Bill Welch has passed on we've lost the last of the factory trained wizards on the old stuff, he was doing most of Walther's "classic" repairs and service before he passed. We still go to Ulm, although they value their heritage and they still have a lot of knowledge on the classics, they are not really geared for it. I think Protek bought all of Bill Welches classic stock.

Have Fun
Robin

[Phil Russell]

Thanks again for the info Robin ... I appreciate it and your comments have been added to my little file of 'useful information'.
I too am still puzzled as to what the puffer really does. I am not sure it is a seal as such as there does not seem to be anything for it to seal. The puffer I refer to is called a puffer in the German translation form the Walther site and sits on the 'hammer plunger' next to the hammer bracket. My guess is still that it acts as a combined buffer and bearing to absorb the tendency of the hammer spring to twist / rotate during firing. Without my pseudo O ring puffer the hammer spring assembly tended to jump out of engagement with the trigger bracket ... and always in the same direction. It took quite a bit of effort to push it back as the spring needed to be compressed slightly so that the lugs engaged. Hence my thoughts on spring twist during expansion. One day I will get round to getting a proper puffer .. I wonder what the are made from? Urethane? On initial disassembly of the rifle I now recall some corky like fragments in the puffer area but thought they were from the valve seal as that had disintegrated into the corky crumbly mess. I might just cut myself a urethane disc just for devilment.
I am not a 10m shooter myself but my daughter is, although of late she has been mostly shooting small bore. She shoots at Cambridge and I have fond memories of ferrying her down to Bisley for some national competitions.
Once again, thanks for the info.
Cheers, Phil

[RobinC]

Phil

We always only ever knew them as "puffers", but puffer in German can mean buffer, so you are right. I remember them being a white nylon type material, not "O" ring shape but with square edges, but I am dredging the depths of an old memory!

Have Fun
Robin

[Phil Russell]

Well well, my German is not good enough to know that 'puffer' translates as 'buffer' but when you know this it all seems to fit.
The loading port seals are clearly made from the same material ... I bought two new ones for a rifle owned by the Cambridge 177 Club and they were white, square sides but with a slight raised part on the faces. The old ones were white (well, dirty cream) and cracked.
Cheers, Phil

[Phil Russell]

I decided to get the Puffer/Buffer from Protek.
It is a white material with square (almost) section. OD = 15.75mm, ID = 10.5mm, depth = 3mm, ring width = 2.6mm
Not sure what it is made from, maybe urethane? Certainly not rubber as for O rings.

Cheers, Phil