I am looking at an early production 686 ND. Between the serial number and the model number on the frame there is a 'M' stamped. The 'M' looks to be be the same font as the letters in the serial number. What does this 'M' mean?
Model 686 with a M stamp on the frame
- Thread starter RMS272829
- Start date
It means the gun went back under recall and had the hammer nose bushing replaced.
Casual Smith Nut
Member
Means it’s gonna be a fun one to shoot! 
My late dad bought a 686 new in Sept. 1981, it had the problem and it went in for the mod. I know some collectors look down on it but it's an heirloom gun for me and will go to my older son and his kids. Both he and his younger brother learned to shoot with it. All these years/rounds later the revolver works just fine.
shawn mccarver
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It means the recall work was done. Anytime you buy a used L Frame, you want it to have had this work done.
Recall Description:
“SMITH & WESSON
MODEL 581, 586, 681, 686, or 581-1,
586-1, 681-1, 686-1 & 686CS-1, REVOLVERS
RECALL: Reports have been received from the field where the combination of a SMITH & WESSON L-FRAME 357 MAGNUM REVOLVER and some .357 Magnum ammunition has resulted in unacceptable cylinder binding. L-frame revolvers bearing model numbers:
581, 586, 681, 686, or 581-1, 586-1,
681-1, 686-1, 686CS-1
Cylinder binding can cause a failure to fire. Mishandling a revolver while freeing the cylinder can result in accidental discharge.
Cylinder binding can result from a number of causes, including characteristics of an individual revolver or the use of ammunition, which does not conform to industry pressure specifications or is particularly fast burning. Recent developments in ammunition manufacture emphasize the production of .357 Magnum ammunition with increased velocity and greater primer sensitivity.
Although there have been very few reported incidents of cylinder binding, in view of our concern for our customer's safety and the reliability of Smith & Wesson products in all circumstances, we issue the following warning:
In a situation where a failure to fire can be critical - such as law enforcement or personal protection - do not use .357 Magnum ammunition with an L-frame revolver bearing model numbers 581, 586, 681, 686 or 581-1, 586-1, 681-1, 686-1, 686CS-1 without an "M" over the model number until you have had the revolver modified.
Those who need to use their L-frame revolver under these conditions prior to modification can safely fire .38 Special caliber ammunition.
Smith & Wesson has developed a modification to improve existing L-frame revolvers. This improvement enables them to fire all .357 Magnum ammunition, without cylinder binding. Shipments of L-frame revolvers from our factory after August 21, 1987 already include this improvement.
You can check if your revolver includes this improvement by looking at the left side of the frame when the cylinder is fully open. If your revolver has been stamped either with a "2" or higher number after the basic three-digit model number or with an "M" above the model number, your revolver includes this improvement and does not need modification. If your revolver bears the model number 581, 586, 681, 686, or 581-1, 586-1, 681-1, 686-1, 686CS-1 without an "M" over the model number, it does not include this improvement and your should have your revolver modified.
Smith & Wesson will modify your L-frame revolver free of charge to eliminate the possibility of cylinder binding with .357 Magnum ammunition. Law enforcement agencies wishing to arrange for modification of L-frame revolvers should call 800-458-8469 between 9 A.M. and 6 P.M. Eastern time (MA residents call 413-734-8244). Other users should send their revolvers to a Smith & Wesson Warranty Service Center, specifying "L-frame improvement program" and enclosing their name and return address.
One of the modifications to improve the L-frame revolver is the installation of a new hammer nose. This obsoletes all old L-frame hammer noses (part numbers 4702 and 7513) and all old L-frame hammer assemblies (part numbers 3366, 3378, 3380, 3382, 3391, 4722, 4723, 4726 and 4728) in field parts inventories. Superseded parts should never be fitted into a modified revolver as this may result in malfunction. It is essential for safety that you return these obsolete L-frame hammer noses and obsolete L-frame hammer assemblies for a free exchange to:
Smith & Wesson
Service Department
2100 Roosevelt Avenue
Springfield, MA 01101
Do not return L-frame hammer-nose bushings from your spare parts inventory inasmuch as they are useable in J, N and K-frame revolvers, which are not included in this Product Warning.
We regret any inconvenience this may cause. Smith & Wesson's first concern is the safety of its products and the protection of its customers.”
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thank you all for the information. I do have an early 686 that is shot little and it has never been sent back for the upgrade. Ill kept it as is as a collector piece or shoot it w/38 spl. I am just wanting a newer 686 and see some older 686 w/ the M stamp and the newer 7 round cylinder and trying to decide which one. The pricing difference is too small to matter.
Engine49guy
Member
The "M" mod stamp was only used for the no dash and dash 1 and IIRC the issue was "Soft primer flow back" on a certain brand of ammo from that era jamming the cylinder.
If I find an early gun without the M mod that I intend to shoot wont send it back to have the new hammer bushing mod done unless the gun has another issue that needs fixing because SW will reportedly set the gun back to factory spec gratis at the same time.
If it's an unfired collector gun I prefer no M mod but woukdnt turn my nose up if it had the mod.
If I was carrying an early 686 without the M for self defense I'd at least want to be sure my ammo choice functioned flawlessly before carrying it instead of finding out the hard way.
If I find an early gun without the M mod that I intend to shoot wont send it back to have the new hammer bushing mod done unless the gun has another issue that needs fixing because SW will reportedly set the gun back to factory spec gratis at the same time.
If it's an unfired collector gun I prefer no M mod but woukdnt turn my nose up if it had the mod.
If I was carrying an early 686 without the M for self defense I'd at least want to be sure my ammo choice functioned flawlessly before carrying it instead of finding out the hard way.
It depends upon use or planned use.
I have an early 6" 586. From the outset its only purpose was competitive use firing .38 wadcutters.
So I did not have the mod done.
Even after all these decades, .38 wadcutters are the only loads ever fired through it.
Not that the modification would have had any down side, it just was not needed.
I have an early 6" 586. From the outset its only purpose was competitive use firing .38 wadcutters.
So I did not have the mod done.
Even after all these decades, .38 wadcutters are the only loads ever fired through it.
Not that the modification would have had any down side, it just was not needed.
