Locking Lug Comparison, Pre "A" vs "A" Model

Great pics, Steve.

A picture is worth a thousand words, and this explains the differences better than any 2,000 word essay. Ought to be a sticky!

BRP

Thanks Steve. Once again you have gone way out of your way to educate the good folks here. NOW, how about the magazine dates I PM'd you for? Thanks, Big Larry

This is a copy of my earlier post, with 2 new pictures that "3Dub" was kind enough to merge and add some additional information. This should help out in the identification process.
I would like to thank 3Dub for taking his Sunday afternoon to help out on this.

Here are a couple of pictures that I have labeled comparing the Pre "A" locking lug/safety lever(wing) with the "A" model. The 2 rifles used for comparison are s/n 25454, and 39801 which is a unmarked "A". They are typical examples from each period.
Some items to note are:
1- The safety lever(wing) itself measures 1/2" long, front to back, and is flush with the front end of the safety stem boss on the pre A model. The round safety stem boss measures 1/4" long from origin to front edge. * Notice the spring detent in boss, and the edge margins between its edges and the front/rear edge of boss. This reduces down to near none with the shortening of the safety stem boss on the "A" model.
2- The safety lever (wing) length did not change with the "A" model redesign, however the length of the safety stem boss was shortened .080". This change allows the safety lever front edge to move forward and visually overlap the rear edge of action.
3-The .080" removed from the safety lever stem boss, was added to the thickness of the LH rear locking lug. This changed the nominal thickness from .093" to .173", nearly doubling its size, and eliminating the cracking/fracturing problems associated with the pre A models.
Take a look at pictures, and hopefully this will make the changes a little easier to understand, and hopefully easier to spot from a distance.
Steve

First, the Pre "A"


Now the "A"


3Dub's additions: