Hello All,
I'm looking for a post or source to find out more details on the engineering changes or dash updates.
Specifically I would like to know the changes from 686-4 to 686-5. I have found many post that give the general change but not details.
This is from another post "686-5, 1997, change frame design to eliminate cylinder stop stud, eliminate serrated tangs, change to MIM hammer with floating firing pin, change to MIM trigger, change internal lockwork"
Can anyone tell me, or reference a source that can, on what change was made to the frame and why was the cylinder stop stud eliminated? Good thing, bad thing, easier to manufacture, doesn't make a difference?
I understand the "eliminate serrated tangs, change to MIM hammer with floating firing pin, change to MIM trigger"
What was the change to the internal lockwork? Good thing, bad thing, easier to manufacture, doesn't make a difference?
Thanks for any information you can give me.
I understand your frustration. But there is no source list for the information detail you want. However most of it can be gleened from reading the SCSW, studying the photos of the guns, looking at the parts list that come with guns, and discussion on this forum is also very helpful. Sometimes you know the answer but just don't realize it.
A rule of thumb is that most changes are cost cutting measures, some improvements, and a few are a combination of both.
Are you familiar the cyl stop stud? Usually referred to as the frame stud in the lower left corner of the cyl window on left side of the frame. It stops the opened cyl from sliding off to the rear of the yoke axis shaft. It used to be a separate piece but the 'separate' stud/stop piece was eliminated, not the stop itself. You've probably seen the new enlarged style stop forged or cast integrally with the frame and extending upwards behind the recoil shield. Check out photos of 1997 and later hand ejectors.
In my mind it was a cost cutting measure. Good or bad? Well they seldom need replacement, at least not until the gun is very old and worn, but if they did how could it be replaced?
Change internal lockwork: typically you'll only be able to figure this out by studying the inside of two guns, one with the change and one w/o it. In the few cases where I've done this, when I figured it out I was disappointed as in big deal, oh, is that all it is???
Usually a good clue to what it might be is when you see a part # listing; use this part # up to 1997, but this part # after '97. If you compare the two parts a little angle was eliminated here or there's a slightly different shape added here, etc. Again sometimes these are cost cutting, or sometimes an improvement to eliminate poor function that has come to the attention of the design engineers.
One example recently discussed here is when the endurance package was added to the 44 mag, completed on the Mod 29-5. The book says a cyl bolt block was added to keep the cyl closed under heavy recoil. With really hot loads that the gun can handle, but the cyl popped open or skipped a chamber. What they didn't tell you is that the hand required a change because of that: we had to figure out that also the 3 pin hand went to a two pin hand and the 2nd pin was elongated to operate the new bolt block.
Most people could care less and the SCSW 4th edition is already twice as thick as the third ed.
If we had access to design dwgs, we could figure out the changes.
Here's the last part of a list I put together that Jim Supica added to his 4th ed. of the SCSW, pg 492 thru 497:
Post 1961 Key dates of changes & Notes:
1962 – J frames only (c. #295,000 on the Chiefs Spl.), the hammer to spring strut junction changed from ball/socket to the fork/pin.
1965 - Bangor Punta on boxes and paperwork. Bangor Punta Corporation headquartered in Greenwich, Connecticut didn't exist until 1964, when it appeared out of the merger of old Bangor and Aroostook Railroad in Maine with the Punta Alegre Sugar Company & RR of Cuba. BP finalized the purchase of S&W in 1965.
1966 - change order February 11, 1966 from 3rd style flat latch to standard thumb piece on J frames and Airweight K frames.
1966 - 44 Magnum (Model 29-2), the front sight and ramp were pinned to the barrel. The change to forge the barrels one piece including the front sight occurred around serial # S270000 beginning with the most popular 6-1/2" length. The change to 4" & 8-3/8" barrel lengths followed thereafter as inventory was exhausted.
1967 – Relocation of the rear sight front tang screw forward, 14-3, 15-3, 18-3, & 19-3.
1968 - delete diamond around escutcheon October 11, 1965 and escutcheon nut on Magnas January 11, 1966 and marked the beginning of the change to stocks without the diamond. Magnas w/o diamond reported as early as 1966. 1968 - Order to delete the diamond on NT and KT stocks December 28, 1967
1970s Side plate logos relocated higher so not partially covered by the stocks.
1973 - Stock med washers (circles) changed from black to stainless and the countersunk silver screw escutcheons to flat brass
1977 change from gas ring on cyl to yoke and back again 10-7 & 8 (page 175-176 SCSW, 3rd ed.), 14-4, 15-4, 18-4, etc.,
1979 - Stock numbering ceased, (with the Model 520 being one of the last models w/#d stocks although seldom matched the gun!)
c. 1980s – It's unclear when the New style extractor star began, but may have been this early, and coincident to serial # deletion.
1981-1989 - optional .400" grooved target trigger K, L & N frames (which always shared triggers).
1982 - eliminate pinned barrels and recessed chambers (on models that had them).
1980 - begin using 3 alpha/4 numeric serial numbers.
1984 - Lear Siegler on boxes and on paperwork. In 1984, Lear-Siegler bought BP and all its assets.
1984-5 - Stock washers eliminated behind medallions.
1984-89 – .400"/.335" J frame and .500"/.400" K, L & N frame grooved and smooth target triggers deleted.
1986 - New standard trigger: .312" J and .320" K, L & N smooth combat trigger became standard.
1987 - S&W purchased by Tompkins PLC.
1988 - New yoke retention screw with plunger.
1995-96 - MIM parts introduction starting with modern style thumb piece with shaved off lower half, date varies by model. Delete sq butt N frames.
c. mid 1996 - New extractor/ratchet shape use completed on all models.
1996 - August, JM (J Magnum) frame introduced
1997 - Lear-Siegler divested S&W in 1997 to Tompkins PLC.
1997-8 – MIM hammer and frame mounted firing pin and hollow trigger (date and dash number vary by model), delete serrated grip frame tangs, cyl stop stud (frame lug) made integral with frame.2001 - Internal lock and fired case inclusion began
2009 – Classic Series produced
Smith and Wesson dates of change are never absolute and there was most always a transition period for changes. The date of production and the date of shipment from the factory will vary from a short time to quite a long time. A 'letter' will pinpoint the ship date but only the features of a gun will help pinpoint the actual production period.
Hope that helps,
