Hi All,
Just thought I would start a thread about commonly encountered faults in collectable air rifles and pistols. As I go around viewing old airguns I see the same recurring faults on a few of the guns I find, so I thought I would list some of them, to help others during their airgun collecting travels.
My main area of interest involves pre-war BSA underlevers, and as these are very simple in their design, there is not too much that can go wrong with them, however here are a few faults that I have seen

Wrong Sights – BSA Cadet and AirsporterMk I sights fitted in place of the original sights. Earliest BSA’s have a low rearsight with a small elevation wheel. Improved Model D’s should have the No.10 rearsight, which is wider and has a larger offset elevation wheel, and the post WWI ‘Standards’ have a high rearsight and foresight fitted. The rearsight on these overhangs the barrel, and has a solid centrally aligned elevation wheel. If the elevation wheel has a hole and spring in the centre, it is the wrong one.

Gun fails to cock – Trigger and sear either broken, or missing or clogged up with old grease and dirt. I have also encountered return springs missing on the trigger. Early pre-WWI guns had a one piece trigger, with trigger adjustment through the trigger guard.Occasionally the trigger adjustment screw has been screwed in too far so that the sear fails to engage. Back off the trigger screw and retry.

Wrong screws and bolts - Check screws for later replacements. Check that screws match and patination is the same etc. Original replacements are hard to find and often expensive.

Stock Damage –Steel locating peg in trigger block often found rusted, leading to split stock at the top of the pistol grip. Missing stock bolt cover- Very difficult to source original ones, and time consuming to carve replacements.Water damage where guns have been stood up in damp conditions.

Low on power/poor compression – Often encountered dry piston seals on these guns,and seals which have disintegrated over time. Also look for foreign objects imbedded in the face of the piston, leading to a poor seal. Broken springs or wrong replacement springs also found.Occasionally the screw securing the piston seal to the piston shears off leaving the piston washer separated from the steel piston.

Underlever does not lock – The button catch on the inderlever can become bunged up with dry grease and dirt preventing the button working. Also the spring loaded plunger on the early bayonet underlevers can also become jammed with dirt and grot. I also once came across a later end button underlever that would not engage with the catch post because the end of the post had become bent and the undercut had become distorted preventing the catch operating.


I have never encountered a BSA underlever with a mis-aligned tap, however I have come across this fault with several Webley MkIII’s.
Lastely because all BSA underlever components are readily interchangeable, I have often found ‘S’ and ‘T’ prefix .177’s and I have also seen an ‘L’ prefix .22! not to mention many wrong stocks for a given model type ( eg a post 1919 style rounded stock on a ‘The BSA Air Rifle’ dating from 1906) so watch out and consult books to check how the gun should look.
Has anyone else got any experience of regular faults they have found on other collectable airguns??

ATB

Lakey