HW45 Service time???

[clarky]

https://imgur.com/uM0zCXn
https://imgur.com/Bx7pBz1

I added a ptfe sleeve to mine, mainly to stop any grease from the spring getting into the comp chamber. Also polished the piston lightly and buffed a light coat of high moly paste into it. Seemed to cut the dieseling down a bit, but it felt a little rough to cock, so i had to add a little lithium moly grease to the cocking slot to smooth it out a bit.

I wouldn't have thought it would need servicing again for thousands of shots as you run these guns pretty dry. I doubt you'd ever fire enough shots to find out its lifespan.

If you use a small top hat ...it will centralise the spring in that piston...then go for a delrin guide at the other end of the spring....you can then do away with the grease..and no need for the PTFE liner..
A touch of Napier gun grease on the cocking slots (i hate Moly on pistols....its too mucky) and your away...
It wont exceed 5 ftlbs without some piston weighting mind but becomes awful to shoot piston weighted ..

[Shed tuner]

Biggest improvement for these is to fit a red Aussie piston seal, to replace the useless hard delrin std item that causes dieseling and harsh shooting.

[clarky]

Biggest improvement for these is to fit a red Aussie piston seal, to replace the useless hard delrin std item that causes dieseling and harsh shooting.

It might help but the reason the damn thing diesels is because of dodgy compression parameters.
In order to get compact full power they went for barrel over cylinder design which brings inefficient transfer port issues ....to offset this they packed in more spring but its enough to easily cause flash over issues of even a trace of emoilents in it ....it needs very careful meddling to get it right...
A kit i did and also done by Tinbum tames the bugger but its no 5 ftlb poser after the mod....it needs plenty of piston weight for that....Tricky gun.

[tinbum]

Our's aren't struggling for power, the new sprung version of the kit needs coils removing in most cases!
I had mine at the June springer bash and at "half" power it is almost 4ft/lb and virtually recoiless.

[clarky]

Our's aren't struggling for power, the new sprung version of the kit needs coils removing in most cases!
I had mine at the June springer bash and at "half" power it is almost 4ft/lb and virtually recoiless.

what you making on full stroke without piston weighting..

[tinbum]

what you making on full stroke without piston weighting..

Mine in .177 is at circa 5 with two coils removed from factory spring. Nothing else done except damn good polish.

[tinbum]

Biggest improvement for these is to fit a red Aussie piston seal, to replace the useless hard delrin std item that causes dieseling and harsh shooting.

The trick is dry firing the pistol twice to size the PTFE seal. It's a horrific experience, but needs doing.

[MikeHW45]

Im actually not too unhappy about the way my hw45's fire to be honest. I'm getting a five shot grouping at ten yards that can be covered by a two pence piece and as for plinking I'm dropping tins, cans, bottles etc at 20-25 yards without a problem. they are tricky guns indeed but they are so worth the perseverance. I have around 9 pistols and the 45's are my favourite. I also have an hw 75 pneumatic with is amazingly accurate but has non of the excitement of the 45's

[tinbum]

Im actually not too unhappy about the way my hw45's fire to be honest. I'm getting a five shot grouping at ten yards that can be covered by a two pence piece and as for plinking I'm dropping tins, cans, bottles etc at 20-25 yards without a problem. they are tricky guns indeed but they are so worth the perseverance. I have around 9 pistols and the 45's are my favourite. I also have an hw 75 pneumatic with is amazingly accurate but has non of the excitement of the 45's

Agreed, its the quirkiness that is appealing.

[Shed tuner]

The trick is dry firing the pistol twice to size the PTFE seal. It's a horrific experience, but needs doing.

I know ,but it's still crap.

Mine now does over 5 FP, without diesleing, and is much softer to shoot

[clarky]

I know ,but it's still crap.

Mine now does over 5 FP, without diesleing, and is much softer to shoot

Maybe this is the way to go ....i have a piece of the same stuff....ill modify and adapt to fit one...
Ive played with the damn thing for years and years, since it was first introduced.
Had about 70 club members in that time all give up on them.
The entire MPl league disowning it....
I originally played Delrin guides and stuff for it 10 years back and found running it completely dry gave some improvement...
The spring and compression ratio flashes over for fun if any oils are in it ....so going Delrin i ran dry ..
....but down goes the power from its potential 6 ftlbs.
I usually make about 5.1 ftlbs instead of its achievable 5.75ftlbs going this way.
I did a mod around 2004 which employed a solid Brass piston weight smaller in dia than stock, then machined up an outer sleeve in Delrin....to form the same dimensions as the stock steel guide...
Allowing weight but also the ability to run it dry....a combination if you like...
I was shocked to get 5.9ftlbs....weight and extra slip of the delrin was what i was after at that time...and this worked in power terms ... but within 12 months i ripped it back out and binned it..
It was still too thumpy...
In final conclusion i believe plain old delrin is best for guide and top hat and being happy with 5.1 ftlbs ..

Found the old Gamo Center a much better gun and ive done some wonderful things when tuning these if anyone is interested.

[Shed tuner]

Maybe this is the way to go ....i have a piece of the same stuff....ill modify and and adapt to fit one...
Ive played with the damn thing for years and years, since it was first introduced.
Had about 70 club members in that time all give up on them.
The entire MPl league disowning it....
I originally played Delrin guides and stuff for it 10 years back and found running it completely dry gave some improvement...
The spring and compression ratio flashes over for fun if any oils are in it ....so going Delrin i ran dry ..
....but down goes the power from its potential 6 ftlbs.
I usually make about 5.1 ftlbs instead of its achievable 5.75ftlbs going this way.
I did a mod around 2004 which employed a solid Brass piston weight smaller in dia than stock, then machined up an outer sleeve in Delrin....to form the same dimensions as the stock steel guide...
Allowing weight but also the ability to run it dry....a combination if you like...
I was shocked to get 5.9ftlbs....weight and extra slip of the delrin was what i was after at that time...and this worked in power terms ... but within 12 months i ripped it back out and binned it..
It was still too thumpy...
In final conclusion i believe plain old delrin is best for guide and top hat and being happy with 5.1 ftlbs ..

Found the old Gamo Center a much better gun and ive done some wonderful things when tuning these if anyone is interested.

That's a lot of work. I just changed the piston seal that was causing the problem 😉

[Geezer]

Maybe this is the way to go ....i have a piece of the same stuff....ill modify and adapt to fit one...
Ive played with the damn thing for years and years, since it was first introduced.
Had about 70 club members in that time all give up on them.
The entire MPl league disowning it....
I originally played Delrin guides and stuff for it 10 years back and found running it completely dry gave some improvement...
The spring and compression ratio flashes over for fun if any oils are in it ....so going Delrin i ran dry ..
....but down goes the power from its potential 6 ftlbs.
I usually make about 5.1 ftlbs instead of its achievable 5.75ftlbs going this way.
I did a mod around 2004 which employed a solid Brass piston weight smaller in dia than stock, then machined up an outer sleeve in Delrin....to form the same dimensions as the stock steel guide...
Allowing weight but also the ability to run it dry....a combination if you like...
I was shocked to get 5.9ftlbs....weight and extra slip of the delrin was what i was after at that time...and this worked in power terms ... but within 12 months i ripped it back out and binned it..
It was still too thumpy...
In final conclusion i believe plain old delrin is best for guide and top hat and being happy with 5.1 ftlbs ..

Found the old Gamo Center a much better gun and ive done some wonderful things when tuning these if anyone is interested.

Do write up your Gamo tuning experiences at some point. I used to have a Falcon, but it was a nasty harsh thing to shoot with an awful grip. I'd be interested to hear how they can be improved.

[clarky]

Do write up your Gamo tuning experiences at some point. I used to have a Falcon, but it was a nasty harsh thing to shoot with an awful grip. I'd be interested to hear how they can be improved.

Its possible you were running loose fit pellets ...
The sliding breach prefers good snug pellets ...preferably Hobbys ...at 4.53 ...
But i suspect your gun wasnt sealing as well as it should...either from the breach or piston seal.
As stock, they are lovely shooters, with good piston stroke/compression parameters provided they are in good order.

The sliding breach unit may seem a little doubty but infact gives perfect alignment and the hard plastic results in a low friction release of the pellet and wears very well.
Rebuilding with delrin top hat and guide i had one running 500 fps on a stock piston seal ...
Further, the slight twang and vibration they have was killed stone dead.....ive done 2 now for club shooters.

The guide is actually integral, made of steel and also acts as the main receiver which houses the sights.
So you cannot replace it totally.
I simply turned down the steel guide section to 8mm...then machined up a sliding cover of delrin.
This looks like a traditional guide rod with a hole to pass over the existing modified guide ...also the usual flange which sits down on the main bulkhead as with any other guide rod.
Top hat was added although did not make much difference......
A slip washer at either end took out any hint of torque..
The piston is nicely relieved along its length like a quality air rifle. The bearing sections of which taken to high polish.
Used some Napier power grease which is thinner moly halfway between SM50 and and regular Moly ...ideal for pistols

Unlike the HW in our discussion, this thing then turned in one holers off a pistol rest at 10 Mtrs...
Knockdowns at usual pistol ranges no problem.
The Center grip is adjustable and feels very nice for semi anatomical grip....suprisingly i couldnt get on with the target grip version ...but another member quite likes his.
Not tried the Falcon grip.

[TonyL]

Biggest improvement for these is to fit a red Aussie piston seal, to replace the useless hard delrin std item that causes dieseling and harsh shooting.

I seem to recall that they're 25mm, Jon?

Would the standard factory HW30 seal work, ie same fitting at the rear?