HW35 The Collectable Weihrauch

[Muskett]

T20
Might have to find a copy of Airgun World; good excuse as I only buy one once a year.

Wow; the John Bowkett article is major engineering. Many thanks for sending it to me. Very interesting, and for those who don't have a copy you really need some serious engineering equipment and know how to do the work.

In truth other than a strip, clean, de-burr and tar and moly thats about me. However, I think a fully worked HW77 might be in the offing as it would have the nostalgia and accuracy that I want. Something for me to think about.

[coburn]

I remember Terry Robb doing a similar thing on the 80 in a publication called "Power without Powder". Does anyone have a copy?

[T 20]

I remember Terry Robb doing a similar thing on the 80 in a publication called "Power without Powder". Does anyone have a copy?

Hi Coburn

Terry Robb's book (can't remember the title) was a bit vague to say the least.

Power without Powder was written by Mike Wade of Mike Wade engineering.
I had a couple of long chats by phone with Mike in about 1985 when ordering his book and when ordering some parts (nice chap).
The book is a step by step guide to tuning the HW80 to about 21 ftlb's, and is a very good read.
Power output for a HW35 is shown at 13to15ftlbs for a .22" gun with a honed air cylinder and enlarged transfer port running a PTFE piston head and stronger spring.
Power output for a HW80 is shown at 19to20ftlbs for a .22" gun.
Power output for a HW85 is shown at 17to18ftlbs for a .22" gun.
Power output for a HW77 is shown at 16to18ftlbs for a .22" gun.
These outputs are not in the book, they are taken from the order form Mike sent me for his Viper Power Products.



Hi Muskett

Glad you liked the Bowkett Article on the HW77.
I'm going to have my two 77K's burried with me.

All the best Mick

[coburn]

Hi T20 might need some help on 35 tuning. My 35K arrived yesterday and looks to be in good nick. Its been unused for a while and is very "dry" lube wise.

I've fitted an Anschutz Dioptre and it shoots RWS Superdomes into one ragged hole at 12 metres however over the Chrono after a squirt of SM40 in the transfer port I get a mere 520fps with Superdomes and 580fps with Hobby. Not great for .22.

I intend to strip, inspect and lube but can anyone tell me what length a std 35 spring should be?. Also I remember many people on here writing that HW springs of late were fairly mediocre is that true?

[T 20]

Hi T20 might need some help on 35 tuning. My 35K arrived yesterday and looks to be in good nick. Its been unused for a while and is very "dry" lube wise.

I've fitted an Anschutz Dioptre and it shoots RWS Superdomes into one ragged hole at 12 metres however over the Chrono after a squirt of SM40 in the transfer port I get a mere 520fps with Superdomes and 580fps with Hobby. Not great for .22.

I intend to strip, inspect and lube but can anyone tell me what length a std 35 spring should be?. Also I remember many people on here writing that HW springs of late were fairly mediocre is that true?

Hi Coburn
I really couldn't tell you what the original size of a HW35 spring is.
Perhaps this would explain why

http://www.airgunbbs.com/forums/showthread.php?t=301845

I hope this explains the situation with my 35.
As a coded welder I believe there are many HW35's out there with poorly brazed breach block joints.
Jim Tyler (BTDT) in his recent article in Airgunworld (Feb 2009) says this problem occured in the 1970's in a few 35's, I just wonder if the problem still happens once in a while and gets missed at quallity control.
I don't think you have one of these Coburn as your power output is fairly high compared to a poorly breach one.

From the Weihrauch site it would seem that the HW35 is only advertised as doing 574 ftps in .22" calibre.

http://www.weihrauch-sport.de/englis...te/e-index.htm

When I get five mins I will scan all the articles I have on tuning the HW35 so that I can send them to other members.

Hope this lot helps you a bit for now Coburn

All the best Mick

[coburn]

Just retried it over the chrono. Its averaging 9.5ftlbs with Hobby but only 8.6ftlbs with Superdome. I really need to get round to giving it a strip and lube. I suspect a lube problem because in my string of 12 shots with Hobbies its first shot was 618 followed by a gradual decent to 597fps. There was no dieselling or smoke at all.

However whilst I had the stock off I noticed that the spring guide appears to be a synthetic material! I was under the impression that HW's were fitted with those horrible rolled steel ones. Can anyone enlighten me.

[T 20]

Just retried it over the chrono. Its averaging 9.5ftlbs with Hobby but only 8.6ftlbs with Superdome. I really need to get round to giving it a strip and lube. I suspect a lube problem because in my string of 12 shots with Hobbies its first shot was 618 followed by a gradual decent to 597fps. There was no dieselling or smoke at all.

However whilst I had the stock off I noticed that the spring guide appears to be a synthetic material! I was under the impression that HW's were fitted with those horrible rolled steel ones. Can anyone enlighten me.

Hi Coburn
Chambers show a synthetic spring guide for the 35, I don't know if this is the standard fitment now.
With your gradual drop off in power it may be worth checking the breach seal for leakage, these can be shimed out with paper or thin card if needed.

From your chrono results it seems your gun is only 50 to 70 fps below the 12ftlbs limit with Hobbies. I would strip, clean, and lube the gun, I would also change both seals (£10) and see what it does then.
On second thoughts I would change the breach seal and just inspect the piston seal for wear and fit as it wouldn't appear to be that bad from your chrono results.

If you need a tuning kit for your gun, Bonnie and clyde has just put together a kit for the HW35, check it out on the revue section.

All the best Mick

[uk litehammer]

I intend to strip, inspect and lube but can anyone tell me what length a std 35 spring should be?. Also I remember many people on here writing that HW springs of late were fairly mediocre is that true?

Hi, the standard spring I just bought from Chambers is 9 1/4 inches long.