Quote Originally Posted by diipii View Post
Don't reduce the port size. I drilled mine out to 4mm. What does Cardew know ? I also lightened the piston by drilling holes in the shaft and raised the point of impact 2 notches on the rear sight and the gun (HW35) shoots very smoothly. p.s. you will get a zillion pet theories about this but that's all they are.
What Bigtoe and T20 will aim to do, on most examples, is not to reduce, but to increase the TP diameter. What they aim to reduce is the LENGTH of the TP, raising the static comp ratio, thus increasing efficiency.
If you look at the most efficient guns on the market, they have short transfer ports, like the HW77/97, HW80, Diana 52 variants and I'd guess the Air Arms TX and Prosport and the HW95.

The HW35, as much as I love them.....I had three until this morning, now four, is an old design and not as efficient. Lovely, lovely rifle with lots of character and charm, accurate and powerful and able to do the business today, but it isn't as efficient as some of these later models.

Until you look at Mick's HW35/LGV 25mm conversion with the short transfer port.