HW 77/97 refurbish & venom tune

[Gibbon]

SmilerGB : Yes, I'd noticed the error (thanks to previous threads) re the piston sleeve & fitted it @ 180° to the cocking slot

Well, I've reassembled the action (with broken beartrap spring) back in the stock, scope's back on & zeroed with 4 shots whilst being very careful during loading !

Cocking is smooth, but more effort is required. The spring twang has completely gone - just a dull thud now - the rifle is A LOT quieter than before - recoil is negligable

Just had to get the Chrony out, couldn't resist ... here's the figures using JSB Exact 4.52 :

Before/After
743.8 825.5
747.9 826.2
738.1 824.5
743.7 827.0
753.4 824.7
755.1 824.7 (not a typo error !)
748.1 826.8
758.3 825.5
753.2 826.9
767.7 827.1

Anybody got an idea how much the velocity would increase if I put the other 2 washers in ???

[Akshay D.]

I've used all the washers with the Venom FAC kit and the velocity increase with H&N Finale Match 4.50 mm was about 50fps. Originally it was shooting at 810fps and after installing the kit with all the washers it's shooting at an average of 860 fps. After approximately 1000 shots its shooting at 875fps.

Regards,

Akshay

[paterdale]

You may find that the pins tap out from one direction a lot easier (they dont normally require too much effort). With ref to the problem mentioned earlier.

[Gungeek]

My tip for when reassembling the anti-bear-trap device is to use Loctite lock 'n seal on the threads of the Stock Lug, part no. 8988. Regards ... Geek

[RAGS]

Hi Guys,

Any idea of the expected velocity in a 77/.22 with an venom FAC spring?

[Rustam Bana]

I've used all the washers with the Venom FAC kit....

Are you sure? I thought we had only put in two or three?

Rustam

[Rustam Bana]

Hi Guys,

Any idea of the expected velocity in a 77/.22 with an venom FAC spring?

You will be looking at around 17 ft.lbs.. With a 14.5 grain pellet that works out to 726.5 ft./sec.

Good enough for shooting bobbing coconuts out at sea.

Rustam

[RAGS]

You will be looking at around 17 ft.lbs.. With a 14.5 grain pellet that works out to 726.5 ft./sec.

Good enough for shooting bobbing coconuts out at sea.

Rustam

Well , I assume so, esp as the 77 was doing 680 fps before I went and shot the Chrono . What's with the combro ? Building a pellet-proof vest are you

Shooting cocunuts at sea is a sport reserved for the CZ

[Akshay D.]

Are you sure? I thought we had only put in two or three?

Rustam

We've used all the washers Rustam, 4 of them I think. Remember I told you I want it maximum power .

Akshay

[Rustam Bana]

What's with the combro ?

Yet to send it to Robin for his kindly ministrations. May have to send the other one as well, as Akshay dropped it on the floor.

A friend proof chrono rather than a bullet proof one seems more appropriate.

[Rustam Bana]

We've used all the washers Rustam, 4 of them I think. Remember I told you I want it maximum power .

Akshay

But it's only doing 13.99 ft.lbs.

[Akshay D.]

Yet to send it to Robin for his kindly ministrations. May have to send the other one as well, as Akshay dropped it on the floor.

A friend proof chrono rather than a bullet proof one seems more appropriate.

But the rubber band broke, it was'nt my fault . Is it working?

[Akshay D.]

But it's only doing 13.99 ft.lbs.

Very funny , its shooting 14ft/lbs

[Gungeek]

All new 77's and 97's use 26mm piston head seals, older ones were 25mm. I measured my 77's piston diameter (new last September) it was 25.5mm. Fitted a Venom spring, chrono'd: 15.3 ft/lbs, and that's without even trying! Immediately (oh yes) ripped the spring out, sent it back - what else could I do. Waiting for shortened spring to arrive from Venom. Regards ... Geek

[Gibbon]

Wow Geek !

Mine's 'only' doing 12.8 ft/lbs (with 2 washers in)
Do you think I've messed up somewhere ? or perhaps you were using very light pellets ?