Jim, when did the factory move from the flat latch to the pinch type latch?
Hi Mike,
Actually they didn't, the flat latches followed the pinch styles, and were deleted in 1966, replaced by the common standard thumb piece used for the following 3 decades before it was replaced.
The post war I frames had the three different pinch styles of the four standard Thumb latches before they began the 2nd style flat latch in 1952 and then the 3rd style and last style about 1956 thru 1966.
This is something I've researched and the complexity that I have found about all the latches is bewildering:
1. All pre war thumb pieces are the same styles in two sizes: I frame and K/N frame.
2. Post war thumb pieces have many variations:
A. four 'standard' styles used on I frames, two on K/N, but only the 4th style on J frames.
B. 3 'flat latch' styles used on J frames and M&P K frames (Airweights only), and the 2nd and 3rd styles on I frames.
FOUR I FRAME STYLES OF THUMB PIECES USED POST WAR THAT PRECEDE THE FLAT LATCHES:
The four I frame thumb pieces of the .22/32, .32 and .38/32 prior to the introduction of the flat latches, have a completely different evolution than all other frame sizes. And you'll find them out of sequence with serial number advancement and/or gun delivery dates; no surprise to most of us.
These post war revolvers used four different thumb pieces prior to the flat latches starting with left over pre war thumb pieces followed by three different and new standard type thumb pieces ending with the final style, which is the same as the only style used on the first ~117 J frames (Baby Js). Used from 1946 to c. early 1953 (production dates, not shipping dates).
The 1st thumb piece used post war; left over pre war thumb pieces, carried over on the very earliest of the post war 'Transitional' I, (also K & N) frames; the 'double hourglass' or 'double pinch' around screw hole thumb piece with relief cuts/flare under checkered pad shown here on a K22/40.
When the modern 'Classics Series' was introduced, an exact copy of this #1 pre-war style and transitional post war style (old pre war inventory) was introduced on them but is an MIM cast part.
Flared or relieved edge (photo by JP@AK):
2nd style used, and first 'new design' post war style thumb piece, still has the double 'pinch' but without relief cuts under checkered pad.
Flat edge (photo by JP@AK):
The 3rd style used (2nd new post war style) was a single hourglass or single 'pinch' in front of the screw hole like a #1 & 2 but from the center of the screw to the rear it's like a #4 below. Only seen on I frames.
4th style used (3rd new post war style) with no 'pinches' ended on the I frames with the introduction of the 2nd style 'flat latch', just prior to the Models of 1953. It was the style used on the first 117 or so .38 Chiefs Special Model of 1950 'Baby J' frames followed by the #1 style 'flat latch'. This 4th style was used on all K and N frames immediately following the left over #1 pre war style just prior to the Models of 1950.
It was re-introduced on all I, J and K frame Airweights in 1966 and used for several years until the modern style with shaved off lower half took over ~ 1995-96.
THREE STYLES OF FLAT LATCH:
1st style flat latch used only on the Baby J frame and K frame airweights.
Photo courtesy of Jim Fisher
2nd style flat latch began on the I frames, Baby Js and K frame airweights just prior to the Models of 1953.
3rd style shown with steeper incline at the front, on lower .38 Chief Spl. in first photo and in 2nd photo; used on I, full size J frames, and K frame airweights beginning mid late '50s; ending in 1966.
TWO STYLES OF LATCH BACKS – SPLIT AND SOLID:
I & J frames flat latch have split backs:
All pre flat latch thumb pieces are split.
All flat latches are split.
All standard thumb pieces post flat latch are non-split (began ~1966)
K frames:
I have no flat latch K frames but most likely they are split based on the I & J frames above.
All my '50s K frames are split including a 19-1 from 1961.
All non-pinned barreled Ks I have (earliest is 1980) are non-split.
N frames never used flat latches
