Webley Mk3 issues

[Geezer]

Neither are great,but they are proper .22 cal!

Bit of an understatement. They are both rubbish, especially wasps.

Try RWS Superpoints. They may positively surprise you.

[Modski66]

RWS Superdomes seem happy in my 0.22 Senior, as do Hobbys.
My 0.177 Mk3 is a late one, June 1971. The trigger is heavy, but so is the Senior's! It was a lot better after a fettle, so I am hoping the Mk3 will show similar improvements...

[deejayuu]

Thank you. That's interesting. I was thinking about making a brass insert, with a 3 mm hole. And fixing it with Loctite. But your method is certainly more refined.

Do you know how "long" the Mk3 transfer port is? And what its diameter is? (.22" action). Many thanks

The original TP diameter is the same as the rifle calibre. Factory process to ream the tap in situ. involved working from comp. tube end.
This, comically, can result in a pellet being drawn from tap to cylinder if cocked after loading. Slack pellets have been known to fall in if rifle held vertical.
Ours measured 19 mm x 5.5 mm (.22 really) with limited tools.
http://www.airgunbbs.com/showthread....pinions-please

[andrewM]

I have found Superdomes and H&N Sniperlight to perform well in mine.

The link from Deejayuu was most interesting. Within that link was a further link which is worth reading in terms of the posts therein:

http://www.airgunbbs.com/showthread....r-loading-taps

I also noticed these posts:


Prof51mtw
Good Morning Mick: Yes, the compression ratio or, more specifically, the peak cylinder pressure will have an effect on the optimum TP size. Whether lubricant vapour combustion is present also has an effect, as Jim has just pointed out to me, citing the fact that Weihrauch reduced the size of the TP on the HW55 when moving over to plastic piston seals.
Mike

T20 Super Moderator

Thank God for that --- I thought I'd been imagining it.

As Jim has pointed out Weihrauch changed from a 4mm transfer port to a 2.8mm port when they went from leather to synthetic seals --- so in effect they doubled the static compression ratio.

I'm finding leather seals like to work at a sub 200:1 compression ratio and synthetic seals and O rings work best at 300 : 1 upwards.

The Webley MK3 has one of the lowest compression ratios I have found at 80:1, I am considering fitting a Diana 52 piston seal to one of mine and then sleeving the transfer port down to 2.5mm --- on paper this should make it a bit more user friendly.

Unquote.

This is really into the technical detail but also sheds further helpful light on the subject.

A

[thisisdonald]

Right... I've got an old banger of a mk3 here.. how do I tap all the way down the compression tube? Do I need to make an extended tap holder or is there a nifty trick to it?

[jirushi]

The original TP diameter is the same as the rifle calibre. Factory process to ream the tap in situ. involved working from comp. tube end.
This, comically, can result in a pellet being drawn from tap to cylinder if cocked after loading. Slack pellets have been known to fall in if rifle held vertical.
Ours measured 19 mm x 5.5 mm (.22 really) with limited tools.
http://www.airgunbbs.com/showthread....pinions-please

Thanks to all above for the input. @ Modski 66 and Geezer, will get some RWS Superpoints and Superdomes. I have Hobby's for my Crosman 400 (still not the right pellet for that multishot mechanism, just to go off-topic a bit). Will give them a go.

Very good info here, deejayvuu. What an enormous transfer port If this were a pcp, you could shoot deer with it
19 mm long - good heavens. Thank you for the link

[jirushi]

I have found Superdomes and H&N Superlight to perform well in mine.

The link from Deejayuu was most interesting. Within that link was a further link which is worth reading in terms of the posts therein:

http://www.airgunbbs.com/showthread....r-loading-taps

I also noticed these posts:


Prof51mtw
Good Morning Mick: Yes, the compression ratio or, more specifically, the peak cylinder pressure will have an effect on the optimum TP size. Whether lubricant vapour combustion is present also has an effect, as Jim has just pointed out to me, citing the fact that Weihrauch reduced the size of the TP on the HW55 when moving over to plastic piston seals.
Mike

T20 Super Moderator

Thank God for that --- I thought I'd been imagining it.

As Jim has pointed out Weihrauch changed from a 4mm transfer port to a 2.8mm port when they went from leather to synthetic seals --- so in effect they doubled the static compression ratio.

I'm finding leather seals like to work at a sub 200:1 compression ratio and synthetic seals and O rings work best at 300 : 1 upwards.

The Webley MK3 has one of the lowest compression ratios I have found at 80:1, I am considering fitting a Diana 52 piston seal to one of mine and then sleeving the transfer port down to 2.5mm --- on paper this should make it a bit more user friendly.

Unquote.

This is really into the technical detail but also sheds further helpful light on the subject.

A

That's great Andrew, thank you.
Great info. Very technical, yes. But with the tp measurements at hand, it shouldn't be too difficult to make a brass insert (is that the word?) to fit the tp, and then drill a 2.8 or 3 mm hole in it. Degrease the tp, some red Loctite on the insert, and then a long rod to place it in the tp. Luckily I know someone who is good with metal work haha.
Would be a lot easier than tapping the tp.

[andrewM]

That's great Andrew, thank you.
Great info. Very technical, yes. But with the tp measurements at hand, it shouldn't be too difficult to make a brass insert (is that the word?) to fit the tp, and then drill a 2.8 or 3 mm hole in it. Degrease the tp, some red Loctite on the insert, and then a long rod to place it in the tp. Luckily I know someone who is good with metal work haha.
Would be a lot easier than tapping the tp.

It is quite a fine operation, to ensure no jagged bits intrude and there is no overlap into the tap area. The TP diameter also seems to depend upon whether or not you use a leather washer, in which case the tp would be rather larger that with a synthetic washer. The links previously mentioned cast quite an amount of light on the optimum size for the tp, especially for the Mk3. I suppose, if you make a narrower tp, then you can then always widen it whereas the reverse is not so simple.

It will be very interesting to know how you get on.

A

[jirushi]

It is quite a fine operation, to ensure no jagged bits intrude and there is no overlap into the tap area. The TP diameter also seems to depend upon whether or not you use a leather washer, in which case the tp would be rather larger that with a synthetic washer. The links previously mentioned cast quite an amount of light on the optimum size for the tp, especially for the Mk3. I suppose, if you make a narrower tp, then you can then always widen it whereas the reverse is not so simple.

It will be very interesting to know how you get on.

A

Thank you Andrew. I can't wait to test the rifle with the sleeved tp. I will go for 2.8 mm first. A friend is making a brass insert, 5.6 mm. I will try to find a way to measure the exact diameter of my transfer port, but if it's actually 5.5 mm, I can always reduce the diameter of the insert.

Tested RWS Hobby's this morning before work. Don't know how they group, but power is up to 6.6 ft/lbs (500 ft/s, 11.9 gr).
That's already a lot better. But the gun is slammy.
Yes I need a smaller tp

Also did some adjustments to the trigger. It's very good now! On the verge of being dangerous. I will increase sears engagement a bit to be on the safe side. I only need the lightest amount of pressure to fire the gun. This is a third variant trigger. Not as pretty as the second and first, but it's rather good! I'm sure that polishing helped, but it's easy to adjust too.

[andrewM]

Thank you Andrew. I can't wait to test the rifle with the sleeved tp. I will go for 2.8 mm first. A friend is making a brass insert, 5.6 mm. I will try to find a way to measure the exact diameter of my transfer port, but if it's actually 5.5 mm, I can always reduce the diameter of the insert.

Tested RWS Hobby's this morning before work. Don't know how they group, but power is up to 6.6 ft/lbs (500 ft/s, 11.9 gr).
That's already a lot better. But the gun is slammy.
Yes I need a smaller tp

Also did some adjustments to the trigger. It's very good now! On the verge of being dangerous. I will increase sears engagement a bit to be on the safe side. I only need the lightest amount of pressure to fire the gun. This is a third variant trigger. Not as pretty as the second and first, but it's rather good! I'm sure that polishing helped, but it's easy to adjust too.

Be careful not to reduce the trigger pressure too much as it might accidentally discharge, especially if the rifle is knocked.

I erroneously referred to H&N Superlight; I meant H&N Sniperlight and have corrected the error in my previous post.

I also carried out some tests today. Roughly, Sniperlight were achieving approx. 9.5ft/lbs; Superdomes about 10ft/lbs and the old Eley Wasp about 10.3ft/lbs. The power sounds about right but it is worth testing the accuracy and S.Domes seem to perform quite well.

A

[deejayuu]

Right... I've got an old banger of a mk3 here.. how do I tap all the way down the compression tube? Do I need to make an extended tap holder or is there a nifty trick to it?

A square drive/8 point socket on extensions worked OK for me.

[jirushi]

Does someone know if a second type trigger works in my later end block? (as in, will the pins match up, and the sear work)
And if a second type trigger fits in the early stock with grip lines that I have?

I have found a second type trigger (with the profile).
Just making sure that I don't need to find other parts to make it all work.
I should probably simply try to find an entire early Mk3 haha...

I think this great photo of forum member @johnbaz shows the three types of triggers? Not sure. I know the first type is double pull and has a really nice curve. That the second one has a profile at the rear of the blade. And that the third one is this dull straight thick piece of sintered steel, more set back in the trigger guard.

[hwtyger]

Is yr tap aligned properly? If its not you'll loose power too.
Dont worry about pellets. 5.6 barrel dont need 5.6 pellets.
My Tempest with 5.6 barrel shoots best with FTT 5.53 and my mk3 shoots best with JSB iirc

[jirushi]

Is yr tap aligned properly? If its not you'll loose power too.
Dont worry about pellets. 5.6 barrel dont need 5.6 pellets.
My Tempest with 5.6 barrel shoots best with FTT 5.53 and my mk3 shoots best with JSB iirc

Thank you Yana. I haven't inspected the pellets yet after firing. Will follow Andrew's advice to shoot into a bucket of water and check the pellets.
But when I open the tap, the hole is perfectly centered. Not sure if this means a lot though.

Any ideas about the different types of triggers gents?
Are the middle two ones in John's photo indeed second type triggers?
Then I probably need a different trigger block.

[jirushi]

Ps. I need to send forum member Josie & John a message with the trigger/trigger block compatibility question.
This is where I read about the three trigger types:
http://www.airgunbbs.com/showthread....Trigger-weight

Josie & John writes:
"Hi,

You can adjust it. There were three types of trigger on the Mk III. The first was the so called double pull with adjustment screw located on the trigger blade. The second and third had a locking screw on the side of the trigger block, whilst the adjusting screw was located on top of the block. The differences between the 2nd and 3rd types is the 2nd has a curly trigger profile, whilst the 3rd type has a shorter trigger blade, which sits slightly further back. The 2nd type had the best and 'crispiest' pull, whilst the 3rd type probably had the heaviest pull. Ironically the Supertargets were fitted with the 3rd type, which in my experience was the worst trigger on any of the Mk III rifles!

As a rough guide, the 1st type can be seen on rifles serial numbered to 6000. The 2nd type from SN 6001 until the A prefix was introduced in 1966 and the 3rd type on letter prefixed rifles.

John"