Hw35 optimal set up

[charub]

Winter is here and it is time to dig out the old project guns.
I have a dog of a 35 that I want to give some love to. Last year I attempted to solder the porous breech, I am dubious that I succeeded.
So I’m now going down the Loctite or JB weld route.
Whilst at it, I thought I would check what is the optimum transfer port size in a later model with synthetic piston washer?
I’m not overly concerned on overall power, i just want it smooth to plink with

Thanks guys.

[Shed tuner]

2.8ish mm port, synth head piston with the longer 64mm stroke and a few grammes lighter, don't over spring it, and fix that leaky breech. Job done, it'll shoot sweet as...

[Hsing-ee]

2.8ish mm port, synth head piston with the longer 64mm stroke and a few grammes lighter, don't over spring it, and fix that leaky breech. Job done, it'll shoot sweet as...

What is your preferred method of removing weight from a piston, and how much should it weight when its done?

[charub]

2.8ish mm port, synth head piston with the longer 64mm stroke and a few grammes lighter, don't over spring it, and fix that leaky breech. Job done, it'll shoot sweet as...

Cheers.

[Geezer]

I think the consensus is that factory ones ran 2.8-3mm and are fine, though some report good results from opening up to 3.1 or 3.2. I doubt there is much in it.

[Shed tuner]

What is your preferred method of removing weight from a piston, and how much should it weight when its done?

i was reffering to the factory synth piston being lighter as is..

more generally, a slot opposite the cocking slot on the piston always gives a worthwhile weight benefit.. just keep well away from the nose and skirt whilst cutting it..

[CapitalBee]

What is your preferred method of removing weight from a piston, and how much should it weight when its done?

I think the advice concerns replacing the old leather sealed piston with a newer synthetic piston. It increases stroke by 4'ish mm and is lighter. Mick (T20) posted a useful article on it. I've done this myself and it does improve an already good shot cycle, as well as upping the power by at least a ft/lb (possibly 2), allowing you to take some spring out of the configuration.

[Shed tuner]

I think the advice concerns replacing the old leather sealed piston with a newer synthetic piston. It increases stroke by 4'ish mm and is lighter. Mick (T20) posted a useful article on it. I've done this myself and it does improve an already good shot cycle, as well as upping the power by at least a ft/lb (possibly 2), allowing you to take some spring out of the configuration.

yup - about 2 ft lbs for me - a lot of spring had to come off

[charub]

Ok guys, what’s the best method for cleaning up before the porous breech fix. Please bare in mind that I have previously washed a cylinder head in the dishwasher and have been told in no uncertain terms that I should be looking at a bedroom fun band if anything remotely garage / workshop like is washed in there again!!!!

[Hsing-ee]

Ok guys, what’s the best method for cleaning up before the porous breech fix. Please bare in mind that I have previously washed a cylinder head in the dishwasher and have been told in no uncertain terms that I should be looking at a bedroom fun band if anything remotely garage / workshop like is washed in there again!!!!

I think isopropanol is probably the solvent of choice, but a good swill with meths and then make sure it is all evaporated (maybe warm the metal a bit before with a hair-drier - caution though, you don't want to start a fire, so well ventilated and no sparks or flames when you wash it). Brake cleaner also seems to work well, but again its quite expensive.

What is a 'bedroom fun band'? Is it a pop group or some kind of kinky stretchy strap?

[CapitalBee]

Ok guys, what’s the best method for cleaning up before the porous breech fix. Please bare in mind that I have previously washed a cylinder head in the dishwasher and have been told in no uncertain terms that I should be looking at a bedroom fun band if anything remotely garage / workshop like is washed in there again!!!!

I used brake cleaner and some mops / rags. Thinners could work as well. You just want to use something that evaporates after use for no residue. A good trick is to apply the Loctite through a straw with a flexi joint on, that way the Loctite can be directed into the joint.

[TonyL]

A well sorted, sweet shooting HW35.

The '35 first came to my attention back in 1977 with the launch of Airgun World. And I think I got my first one the year after. Loved them ever since.

Apologies for the drawn out nature of the next bit, especially for people that may have read some of my previous ramblings on this particular gun. I bought the gun in question back in 2008 from an old acquaintance. When he offered me it he did say that it was "a bit rough"! I duly went and viewed and yes, it was most certainly a little cosmetically challenged. Rusty and the stock badly scrawked in places. The breech seal was a sticky, goo-ey mess. When I asked him about the seal he said, "Oh, my daughter probably stuck a fruit pastille in there". And it would seem he wasn't wrong! When I asked him how much he wanted he said to make him an offer. I didn't want to as I didn't want to offend. He then said, "Oh, just give me £20". I thought that that was too cheap so we settled at £30,

Once I stripped it, the cylinder and piston were in perfect condition. The leather seal was goosed. I duly ordered a standard spring, breech seal and barrel shims from a shop. They had no leather seals but said that Knibbs may have some. I rang Knibbs who said they had the leather seals so I ordered one. Over the next couple of days the bits arrived........A Titan spring "oh, sorry, no standard ones" which had to be cut down and the seal from Knibbs.....well, not a seal but a synthetic head conversion plus red synthetic seal and a credit card receipt for a larger amount than expected.....naughty, naughty!

Anyways, cutting the very long story a little shorter, I eventually ended up with a V-Mach spring and guide kit and running the Knibbs synthetic set-up.

The gun shot beautifully. Very, very sweet and extremely accurate. The power was low at 7.5ft.lbs, but I decided that that was okay as I only intended using at short range at home on the open sights. At ten yards, if I do my bit, the gun will print pellet sized ten shot holes all day.

So a happy bunny I was.

Then, once I joined the BBS seven plus years ago I came across the leaky breech threads and Mick (T20's) excellent detailed information and also the helpful info from Bigtoe. I had it mind that I might have a go, one day.

Anyway, a few weeks ago, that lovely gentleman Mick donated a later type piston to the cause. Thank you, Mick. And this meant I simply had to do it.

I trawled the 'net for Loctite product but struggled to find the stuff I wanted. But then settled on JB Weld Perma-Lock from "The House of Glues". Product duly arrived. I also ordered up a standard HW piston and breech seal from Knibbs.

When I stripped the gun, the piston was INCREDIBLY tight. Oh yes, just remembered, I chrono'd the gun immediately before the strip.......4ft.lbs! Must be the leaky breech, yes?

Anyway, I applied the Perma-Lock to the cylinder. Polished and moly treated the piston. The V-Mach spring and guide kit looked pristine so we re-used. Rebuilt last week but couldn't chrono due to lighting conditions for the F1. But I did have a plink down the hallway (it was lashing it down outside). Power output sounded healthier and the gun retains its previous superb firing manners and accuracy.

I finally managed to run some shots over the chrono yesterday........I was expecting a rise due to the breech "fix", a much nicer piston seal fit and the increased stroke......result.....an effortless 11ft.lbs and excellent consistency. And that seal still needs to run in!

So, very, very happy. In fact, I'm well made up.

So the spec?.......Standard TP (larger for the leather seal; this is a pre-safety model), piston from the later synthetic sealed guns - lighter and 4 or 5 mm more stroke, standard HW seal, V-Mach spring and guide kit. There's just about no static preload on it. The end of the guide sits a good few mm down the threads, so a good few turns required of the back block before it starts to apply any preload. This makes future strip downs even easier, of course. I also wonder if this also helps with the longevity of the spring?

I absolutely love this gun. It was always going to be a keeper; even more so now.

Cheers for reading.

P.S.....If I have any regrets it's this......If I had more spare time it would have been nice to assess the improvements in individual stages gained from the breech fix, the longer stroke and the much better fitting seal. As I have so little spare time, everything was combined in the one job. I can't remember that red Knibbs seal feeling that tight when I first built it, but it was horrendously tight when I stripped the gun. I wonder if the material isn't quite up to the job and it's been "hammered larger", almost like a PTFE seal with no memory? And maybe, if the breech was leaking, excessively hard piston landing exacerbated this? I strongly, strongly suspect that the huge rob in power may have been due to the horribly tight seal.

[coburn]

A well sorted, sweet shooting HW35.

The '35 first came to my attention back in 1977 with the launch of Airgun World. And I think I got my first one the year after. Loved them ever since.

Apologies for the drawn out nature of the next bit, especially for people that may have read some of my previous ramblings on this particular gun. I bought the gun in question back in 2008 from an old acquaintance. When he offered me it he did say that it was "a bit rough"! I duly went and viewed and yes, it was most certainly a little cosmetically challenged. Rusty and the stock badly scrawked in places. The breech seal was a sticky, goo-ey mess. When I asked him about the seal he said, "Oh, my daughter probably stuck a fruit pastille in there". And it would seem he wasn't wrong! When I asked him how much he wanted he said to make him an offer. I didn't want to as I didn't want to offend. He then said, "Oh, just give me £20". I thought that that was too cheap so we settled at £30,

Once I stripped it, the cylinder and piston were in perfect condition. The leather seal was goosed. I duly ordered a standard spring, breech seal and barrel shims from a shop. They had no leather seals but said that Knibbs may have some. I rang Knibbs who said they had the leather seals so I ordered one. Over the next couple of days the bits arrived........A Titan spring "oh, sorry, no standard ones" which had to be cut down and the seal from Knibbs.....well, not a seal but a synthetic head conversion plus red synthetic seal and a credit card receipt for a larger amount than expected.....naughty, naughty!

Anyways, cutting the very long story a little shorter, I eventually ended up with a V-Mach spring and guide kit and running the Knibbs synthetic set-up.

The gun shot beautifully. Very, very sweet and extremely accurate. The power was low at 7.5ft.lbs, but I decided that that was okay as I only intended using at short range at home on the open sights. At ten yards, if I do my bit, the fun will print pellet sized ten shot holes all day.

So a happy bunny I was.

Then, once I joined the BBS seven plus years ago I came across the leaky breech threads and Mick (T20's) excellent detailed information and also the helpful info from Bigtoe. I had it mind that I might have a go, one day.

Anyway, a few weeks ago, that lovely gentleman Mick donated a later type piston to the cause. Thank you, Mick. And this meant I simply had to do it.

I trawled the 'net for Loctite product but struggled to find the stuff I wanted. But then settled on JB Weld Perma-Lock from "The House of Glues". Product duly arrived. I also ordered up a standard HW piston and breech seal from Knibbs.

When I stripped the gun, the piston was INCREDIBLY tight. Oh yes, just remembered, I chrono'd the gun immediately before the strip.......4ft.lbs! Must be the leaky breech, yes?

Anyway, I applied the Perma-Lock to the cylinder. Polished and moly treated the piston. The V-Mach spring and guide kit looked pristine so we re-used. Rebuilt last week but couldn't chrono due to lighting conditions for the F1. But I did have a plink down the hallway (it was lashing it down outside). Power output sounded healthier and the gun retains its previous superb firing manners and accuracy.

I finally managed to run some shots over the chrono yesterday........I was expecting a rise due to the breech "fix", a much nicer piston seal fit and the increased stroke......result.....an effortless 11ft.lbs and excellent consistency. And that seal still needs to run in!

So, very, very happy. In fact, I'm well made up.

So the spec?.......Standard TP (larger for the leather seal; this is a pre-safety model), piston from the later synthetic sealed guns - lighter and 4 or 5 mm more stroke, standard HW seal, V-Mach spring and guide kit. There's just about no static preload on it. The end of the guide sits a good few mm down the threads, so a good few turns required of the back block before it starts to apply any preload. This makes future strip down's even easier, of course. I also wonder if this also helps with the longevity of the spring?

I absolutely love this gun. It was always going to be a keeper; even more so now.

Cheers for reading.

Excellent post on a rather excellent rifle, I've got four 35's and just bought a fifth for the girlfriend. Love them

[TonyL]

Excellent post on a rather excellent rifle, I've got four 35's and just bought a fifth for the girlfriend. Love them

Snap!

I have five, too. Will hopefully be six, one day........I simply HAVE to have me an Export!

[coburn]

Snap!

I have five, too. Will hopefully be six, one day........I simply HAVE to have me an Export!

Two Exports, one pre safety, a Deluxe and a one owner from new 1979 35 standard still with the factory test target. you've got to love them, I am looking for an earlier Deluxe/Luxus with the Bayern style of stock, one day!