Some time ago I bought a .177 Mk2 25mm 77k from Protek, the first 77 I’ve ever owned. It came with some Venom-ish bits on it (engraved pistol grip cap in brass and a cocking aid) and the internals had bearings fitted though it wasn’t thought to be Venom work when I put pics up on here. There’s a delrin guide and top hat fitted too.

It would have been best described as cosmetically challenged, virtually no bluing, stock varnished with a stick and a broken mainspring. Some lump has clearly had a few good swings at removing the foresight as witnessed by various dink’s in the underside of the barrel. The same lump looked to have tried to remove the end block by bashing the trigger unit, leaving creases in the casing.

I did a rust blue on it which came out pretty well, rebuilt the trigger into a new casing, fitted a new transfer port seal, an Aussie main seal and a Titan spring, I also picked up a nice CS500 stock which puts the bluing to shame.

After screwing it all together it had a pretty harsh cycle, nice and smooth to cock, but not to shoot, the grouping was correspondingly a bit rubbish and the rifle got parked in a corner mocking me whilst life turned itself upside down in more ways than one.

So, after the rambling start.. the rifle is in bits and packed up ready for Paul Chell to work his magic on the metalwork hence this post really. I get the feeling that the Titan spring is probably a bit harsh for the rifle, and has about 1 1/2” of preload. The piston slides through the compression chamber with fairly gentle finger pressure.

So, what would the HW tuners recommend for a spring, amount of preload and (looking at Shedtuner here) transfer port sizing, for a soft shooting action in one of these classics?