HW77 springy underlever

[Bruno27]

I am having the same problem with my early mk2 after fitting the Vortek breech seal. Underlever much harder to close and bends the barrel downward resulting with POI drop ~60mm at 16m.
Wondering about seal thickness as I measured HW (old, may be original): 4.1mm and Vortek 4.6 with a much harder compound.

... The lip on the compression chamber is 2/10ths of a mm...

Could someone explain what/where this lip is please .

[bozzer]

Bruno

So your mk2 is a slide thumb type?

So the rod on the front sight/latch slides inside the hole in the underlever? This is actually bending the barrel down and giving a 60mm POI shift at 16m?

If it was fine before I suppose the obvious answer is to reduce the thickness of the Vortek seal to 4.1mm.

This lip ...

He's on about the front of the compression tube. The bit where you pop the new breech seal in is the comp tube nose ( I'm calling it the nose ). The nose ( which has the recess for the barrel rear end to go into to seal with breech seal ) screws into the main tube of the comp tube. The 'lip' is between the front edge ( face ) of the main tube and the front edge ( face ) of the nose.

There is debate about whether it's a lip ( suggesting main tube is forward of nose ) or a step ( nose is forward of main tube ).

[Bruno27]

Hi

Thanks Bozzer.

Yes it is thumb type slide.

I will forward pics of end of comp tube. May be my riffle has been modified.

[Bruno27]

On the left, original HW, Vortek on the right. 0.5mm difference but a much harder compound.



I now understand about the lip

[T 20]

I'd go back to a standard seal --- I would say bin the Vortek but it looks like it would work in HW break barrel.

The cutout in the Weihrauch seal is so it can compress slightly but still maintain a seal, obviously the Vortek having no cutout and being a harder compound can't easily compress.

The OP had a slightly different problem to you as his underlever was springy without a seal being fitted.



All the best Mick

[Bruno27]

Thanks Mick. I new HW breech seal is now on my shopping list as I have put aside the Vortek seal.
Far too stiff for the job

[Frithy16]

This post may as well have been quantum physics to me