Rifles from New with Notorious Factory faults :

[Geezer]

HW35 porous breech, until they fixed it.
Droopy barrels, for which Dianas get singled out, but far from the only culprit.
Any break barrel using a cross-pin rather than an adjustable bolt.
The FWB Sport trigger/safety mechanism. And the lock-up.
BSF triggers, which seem designed to wear to a point of not being safe. Though can be adjusted successfully.
The plastic used on the Milbro Cougar.
Almost every aspect of the IGI/Gun Toys/Panther RO71 and 72.
Scope rails on Webley Falcons, Mk3s.

[Shed tuner]

Any break barrel using a cross-pin rather than an adjustable bolt.

100%
Can't beleive I missed that, one of my pet hates.

[ken69]

HW100, power dropped to 7ftlbs in my first week of ownership, returned for service and started leaking two weeks later

BSA R10 Mk1, power output all over the place. Replaced with a brand new gun with ‘upgraded internals’ according to my local gun shop. Been absolutely spot on since, never had a problem with the replacement

[Barryg]

One fault that is not popular when mentioned is the cocking link cracking on the HW77/97 especially as there is no ABT and the one that bothers me as I like them and would have bought one, is the linkage and cocking lever on the PS.

[WILBA]

One fault that is not popular when mentioned is the cocking link cracking on the HW77/97 especially as there is no ABT and the one that bothers me as I like them and would have bought one, is the linkage and cocking lever on the PS.

Prosport lever is the most uncomfortable i have ever used. If you have fat fingers then its fime. But boney fingers that dam lever hurts