For anyone looking for British screws etc., British tools & Fasteners in Ilion NY seem to have a good selection. I was looking for what I initially thought might be a 6-40 screw for the rear sight leaf spring of a Martini-Henry rifle. as mine had gone missing. Fortunately another screw on the rifle fitted it and when I measured it and did some searching I found that it was BA4 thread (approx. .140 dia. x 38 tpi, although the spec is actually metric).
And for info on BA and BSA screw sizes, this is useful: http://sizes.com/tools/thread_BA.htm
Stuart
And for info on BA and BSA screw sizes, this is useful: http://sizes.com/tools/thread_BA.htm
Stuart
