Hw70

[TonyL]

Thank you.

[Waddy]

I've just got hold of an early HW70, the medallion bakerlite grip one, serial number 79** so quite early. No cracks in the grip


It's managing 1.5 joules, the breech seal looks newish, and the ancient piston seal isn't that bad at all, it's the type you can't buy so I'll soak it in silicon oil for now.

The insides were smeared in 1970's axle grease, which wasn't far off solid & may be the sole reason for the low power. The spring is sat on a not that well fitting steel spring guide & has 50mm of preload. It's fairly loose inside the piston so it could take a thick sleeve to up the weight from a mere 69 grams

The spring & guide sit inside the screw in rear block, there isn't the intermediate piece as shown in the manual for the later model with safety catch & grub screw into the rear block

Manual with parts diagram for later model https://d1cwyabrhvevux.cloudfront.ne...70-05-2015.pdf


The transfer port seems large, maybe 4mm, but then it's only got a short barrel.

I have a Welsh Willy Dagda spring is a good fit in the piston, but the rear block would need a fraction of a mm removing on a lathe to fit the larger spring. I've got an airsporter spring guide that fits the spring well but that would also require resizing on a lathe to fit the end block

[TonyL]

I'll be watching with interest as to how this fettle goes, Paul.

It might be worth having a quick look at the Mainspring Data Thread and on the Mainsprings section on the Protek site to see if there might be an easier, direct fit spring option?