Webley Tomahawk heavy recoil

[Mark A]

Hi all,

I bought a Tomahawk a long while back from here and I love it, but it does have a surprising amount of recoil. A lot more than I remember my old Longbow having and that was .177, so with the added weight and the Tommy being .22 I was expecting it to have a lot less recoil.

I have taken it apart and the piston is a fair old lump at 285g. Could this be the culprit? If so, is there any way to sort this?

Also does anyone know if this short stroke mod was done by the factory, or has someone tuned it?

[Mach 1.5]

That's a Factory Short Stroke piston with a Webley Venom Seal. What's the spring and guides like? Mach 1.5

[TonyL]

You'd usually expect a fair bit of recoil from the Tomahawk with the big, heavy piston and long stroke. However, with this having the short stroke conversion, just getting the spring specification correct should help immensely and result in a much nicer firing cycle.

If you are using lighter pellets currently, I also wonder whether it might be worth trying heavier pellets / pellets with a higher start pressure?

[BC312]

Has someone put in a heavy spring and opened up the transfer port.

[madcarlos]

The ones I've had including my express , Longbow etc have never had recoil , More of a thud. Always felt like a strut than a spring.

[robs5230]

Hi all,

I bought a Tomahawk a long while back from here and I love it, but it does have a surprising amount of recoil. A lot more than I remember my old Longbow having and that was .177, so with the added weight and the Tommy being .22 I was expecting it to have a lot less recoil.

I have taken it apart and the piston is a fair old lump at 285g. Could this be the culprit? If so, is there any way to sort this?

Also does anyone know if this short stroke mod was done by the factory, or has someone tuned it?

Can you show a pic of the spring / guide setup and give the spring spec and sizes?
What diameter is the TP?
What pellets are you using?

There's always a chance that the seal may need replacing, but it could just need a tweak to settings

[Shed tuner]

my factory tommy piston (short stroke version) didn't have that nose extension. What is the stroke of the gun with that nose ext fitted ?

[Mark A]

I am pretty sure its a Vmach spring, guide and top hat. The spring is 225mm long, not including the top hat or guide. There is very little preload and its making 11.5ft/lb with a delrin slip washer in front of the top hat.




Hmm, the transfer port looks a little odd. I'll take the barrel off later and try and measure the port. A 3.3mm drill bit I had handy seems too large to fit the hole.




I'm using RWS Hobby, RWS superdome and H&N FFT and all give the same heavy recoil.

@Shed tuner How do I go about measuring the stroke?

[Shed tuner]

I am pretty sure its a Vmach spring, guide and top hat. The spring is 225mm long, not including the top hat or guide. There is very little preload and its making 11.5ft/lb with a delrin slip washer in front of the top hat.

Hmm, the transfer port looks a little odd. I'll take the barrel off later and try and measure the port. A 3.3mm drill bit I had handy seems too large to fit the hole.

I'm using RWS Hobby, RWS superdome and H&N FFT and all give the same heavy recoil.

@Shed tuner How do I go about measuring the stroke?

3.0mm for the port is OK.. 3.2 would prob be perfect.

To measure the stroke, look through the cocking slot at a clearly identifiable part of the piston.. e.g. the rear skirt, or the rear of the cocking slot in the piston. Marks it's position with a pencil on the underside of the cylinder in both cocked and uncocked positions. The difference is the stroke. A spare weak spring is great for this, as you can cock the gun without the stock on...

[averageplinker]

Looking at your picture it looks like transfer port has been countersunk or is that an optical illusion?

[hwtyger]

Mine are lazaglided. Still quite lively. Comes with the weight (3.2kg) combined with power (mines FAC)

[Mach 1.5]

The nose extension is from the later pistons. Got a few of these when I helped clear out Mr Pope's garage. Seems a VMach kit may have been fitted, I recognise the white grease. Mach 1.5

[Mark A]

I measured the stroke and it came out at 83mm.

The transfer port seems to be just above 2.5mm. A 2.5mm drill bit fits in there with a little bit of play. Unfortunately I dont have any other sizes to check and cant get my calipers in.

The transfer port is countersunk. Is that done at the factory, or has someone messed with it? Hopefully that wont cause issues

I think the piston seal might be slightly undersized. When I put a finger over the transfer port the piston slowly drops down. Am I right in thinking it shouldn't move at all when you cover the port? If so does anyone know a good replacement seal thats still made for Webleys?

I really wish I would have got it glided a few years ago. I remember my glided Longbow being amazingly smooth to cock. This is kinda rough to cock, despite using moly grease.


Thanks for the help guys, really appreciate it!

[Shed tuner]

so 83mm stroke is not short.. if anything, for a 28mm (or are these 29?) bore, you have too much... this coupled with your port being around 2.5mm and your spring having low preload, your piston will be bouncing quite a lot

I'd open it up to 3.0 without a second thought. In fact I'd go to 3.2 or 1/8", but for that final operation I'd suggest a reamer. You are likely to end up needing a softer spring as a result, so you can still have some preload.

I also agree that your piston seal seems undersized/worn. strip it down and replace at the same time you open the port. Chambers and bagnall & K will do webley spars, as will any of the major spares suppliers.

[TonyL]

Good advice from Jon.

The looks of that "relieved area" around the transfer port are concerning, though. Guessing the breech seal makes its seal around this and not up to the main face, so there must be some lost volume there......