Springer Tuning Projects.

[Geezer]

First thing, chrono' it, you'll never know what spring could be lurking in there. For the action to sound so much on firing, I'd have leant towards the piston seal being a bit knackered (if the breech seal is good) or hopefully no-one has opened up the transfer port to get more power (should be about 3.0mm dia). Otherwise, look to strip it down and fit a suitable spring guide and top hat to match the spring (or match a new spring depending upon results). Strip down is pretty straightforward on the '80, but to be cautious on the first stripdown of this one, I'd advocate the use of a spring compressor.

This is very good advice with any used air rifle, but especially with a used 80. A remarkable number of them, especially older ones, are significantly over the limit, including some that were imported like that - the rest are full of OX Maximiser kits, other huge springs, and drilled out transfer ports.

On the other hand, it may just have dried lube and one of the badly-finished springs that HW were fitting around 5 years ago, and be perfectly legal, just in need of improvement.

[Rickenbacker]

Yup, impossible to say without chrono results.

HW80s are quite capable of feeling horrible to shoot when well under the limit, as well as on it or over it.