Originally Posted by
jmoore
If you search the forum, there's been quite a detailed discussion a while back on the subject of Fazackerly's "A" suffix prevalence. Captain Laidler indicated that it could be something as simple as oversized trigger pivot pin holes, or other wee things that rarely need service, but could cause fits if the rifle components were stripped down willy-nilly (as in an FTR scenario).
A personal example -A Maltby trigger guard that won't fit ANY rifle I've tried. Screw hole spacing is a bit off, I think. So, there's a Maltby receiver body somewhere that also has non-standard scew spacing.
Sorry, can't make longer posts- fitting this in as I can. Work, work, work!