Prewar BSA double sear trigger problem

[edbear2]

Hi Steve,

The reason the pinned one has one spring is that it only needs one, to see what is going on inside it's easy to use the trigger block pivot as a guide and mock up something if you have access to some tube / bit of box. This sort of thing;

https://www.flickr.com/photos/312284...7626485415532/

Or you could maybe make something to hold you action onto a base etc.

Here I set a CD unit on a BSA I modified at the height and position it would be to check sear engagement with a piston rod, so just attach a bit of tube or scrap cylinder to a base, then set up your trigger with a spacer so it's the right height and you will see exactly what is going on as the piston moves back, It is quite enlightening to see how the piston rod ramps over the sear / trigger and then latches when you do this.

The whole double sear system is a rare example of an unnecessary safety (the guns are safe with the tap open) attempt by BSA which was obviously not tested long term, as so many are seen that have been riveted up. When all is good it works well enough, but I doubt guns with the system working get the hard use a gun would have back in the day which obviously brought the problem to light to the dealers / factory.

Pretty much summed up by the fact that the factory "fix" was to disable the whole shebang....The problem getting them to work is also getting the spring balance correct, I have done two or three and it's a pain but can be done (I had a Juvenile which arrived with problems which took ages clipping springs etc. to get the right balance as springs are NLA).


ATB, ED