The B on the barrel preceding the serial # and on the right side grip frame is for the blue finish. The B in the yoke cutout is coincidental and is the civilian inspector stamp (can be any letter).
The S stamp following the serial # on the barrel for Stewart (Gilbert H. Stewart), Gov't inspector, is used w/o eagle head or # following the S; found on cyl, under barrel and maybe frame.
The purple cyl is a common non-factory re-finish indicator. The cyl is heat treated and needs more time in the bluing tank than the rest of the gun to get completely blued.
The frame is a left over WW I military frame, hence the eagle head with S2 inspectors stamp. They were used for commercial models, both .44 and .45, and mostly for the 1946 Brazilian contract. The 1937 Brazilian contract mostly used later/new production frames.
RE-USE OF 1917 SURPLUS FRAMES:
Inspected, but unused serial numbered 1917 military frames preceding and following #169959 (the estimated last military unit made), were assembled thru #209791 by 1946. Some numbered frames went to the Navy and Marines.
Some 1917 frames and parts left over from the government contract with very varied shipping dates were assembled into many commercial model 1917s, and military 1917s to fill contracts for the Brazilian government in 1937 but mostly in 1946. Therefore the s/n is of little help to pin down the shipping dates, but features do help. Any 1917 frames used for 2nd Model 44 Hand Ejectors will have serial #s in the regular N frames serial number series.
There are numerous examples that have the flaming bomb or eagle government inspector stamps in one or more various locations but not on the outside of the frame which were finished off; only in the yoke, and on 45 barrels and/or 45 cylinders. Also fouling cutouts may be found on these frames under the top strap.
Example: 45 ACP all matching serial number is #55639 (assembly #18408 match in all 3 locations as well), it's a round top/U sight notch, has Eagle head proofs inspectors stamps on barrel & cylinder; S24 on cylinder, and an S34 on the barrel. Likely from the 1946 contract because of round top strap and U notch.
War time 1917s did not have S&W trademark logos.
If it has the S&W trademark on the frame it is a commercial gun, at least after ~ 1920, or a Brazilian.
1917 ARMY COMMERCIAL MODEL (not including PW Transitional models):
Produced 10,447 (per S&W Journal Book 2, pg 583). The factory added the 1917 as a regular cataloged commercial model in 1919 catalog (per S&W Journal Book 2, pg 583) and in Catalog D-2 which was issued in Jan, 1921.
Same basic gun as a 1917 Army. That's not to say there were none sold into the commercial market before that; there are 'no rules' that apply.
Features of Commercial models WW I and post 1920:
• Com'l 1917 models have a serial # parallel to the butt like all other Com'l models (with a few exceptions stamped on the front grip strap). The butt # on all pre war guns will read right side up with muzzle to the right.
No "Army" grip mark, or "US Property" barrel mark. (Note: SCSW-3 states some coml. models can be found with barrel mark, but those are most likely military surplus military barrels.)
• Stamped "S.&W. D.A. 45" left side barrel and "SMITH & WESSON" on right side.
• 5-1/2" in cal 45 ACP, and the barrel reads "S.&W. D.A. 45" left side only and likely "SMITH & WESSON" right side.
Bright Blue.
Butt Swivel.
• Frames and sometimes cyls and barrels (w/o US property mark) are usually surplus military with eagle head and S# military inspector marks thru ~ 1926
• MADE IN U.S.A. right side frame except before 1922 or if made on a WWI surplus frame.
• Mushroom knob on all 1917s until post war Transitional Models.
• No hammer block safety until 1933 when 1917s first included the 2nd style side plate mounted hammer block safety (which uses the hand spring in front top of trigger) at ~ # 185,000 per SCSW 3rd Ed., pg 163 w/o an S prefix to butt # because of course it's prior to 1946.
• S&W logo left side post 1920 [until after 12/1936, when changed to large logo on side plate].
• Smooth trigger until serrated trigger order change March 18, 1929.
• Com'l 1917s had Com'l grips of the vintage of when they were made/shipped: In the 1920s they had com'l checkered Svc grips w/o medallions, convex rounded tops. In the 1930s up thru 1941, standard com'l checkered Svc grips with flat silver medallions or pre war Magnas beginning 1938.
• A 1917 Coml #179698 shipped 9/20/27.
CYLINDER HOLD OPEN DEVICE:
In my experience military 1917s had the cylinder hold open detent in the yoke bell crank as did all pre war N frames and some early I and K frames. The cyl hold open detent went away on all frames after WW II with the usual few exceptions that had frames/yokes made pre war. It's been reported that some 1917s do not have the detent as a war time expedient, but of the hundreds of 1917s I've seen all did or at least had the hole with wear evidence that the detent spring and pin were lost. Use caution if you remove the yoke and cylinder from the frame or the spring and plunger can launch across the room to no man knows where.
Plunger shown here in bottom of yoke and has a spring underneath it:
Photo credit: handejector
SERIAL # LOCATIONS:
To confirm all parts are original, one can check for the 6 (or 7 - Triple Lock models only) matching serial # locations for fixed sight pre war Hand Ejectors and all post war Hand Ejectors thru ~1956 and a few as much as 3 years later.
NOTE: Observing some of the serial #s with accuracy or even existence, especially on penciled stocks, requires magnification, bright light, and an attitude that it is there!
1. Grip frame butt (prefixed by a letter(s) following WWII) - or fore strap on I frame Regulation Police models and single shots with grips that cover the butt
2. Barrel - bottom of barrel or in extractor shroud, (Triple locks have tiny #s stamped in front end of the shroud; sideways/vertical if over 3 numerical digits, otherwise horizontal).
3. Yoke - on rear face only visible thru a chamber with a flashlight (except the .32 Model 1896 and no doubt a few others)
4. Extractor star – backside (which is actually the side facing the muzzle).
5. Cylinder - rear face
6. Right stock only - on back, scratched or penciled depending on vintage and stock material, stamped after 1929, (except most post war target grips because individual fitting not required.)
7. .44 TL models only: rear side of middle lock cam plate (Triple Lock models only)