Questions About MIM And The Frame Mounted Firing Pin

[tdan]

Since the original poster was considering a 686-5, I'll chime in with my limited experience: I have two 686-5's. Both are tuned to a 7.5lb. DA pull and are 100% reliable with winchester primers. Neither have required an after-market firing pin. Both are among the most nicely machined revolvers in my bunch. People rave about the older guns, but I've seen plenty that look like the innards were machined with a Dremel tool. No wonder plenty of time was required for hand fitted parts. It's pretty hard to beat the precise work of today's CNC mills. If you actually compare the old hammer nose firing pin to the new frame mount, common sense would tell you that the older style is the more fragile(exposed to damage) part. I have only had to replace one S&W firing pin. It was an older one. I am amused about the folks whining about a design change. Why aren't these same folks whining about the K-22 firing pin design. Last time I checked, they had always been mounted in the frame. Keep your eyes on your sights as you should, and you will never notice that hollow spot in the back of that MIM trigger.............just my 2 cents!

 

[XTrooper]

I probably dry-fired it 1000+ times before the break, something I've done with all my revolvers over the years. Since I was using snap caps, I don't think the dry-firing was a factor in the breakage.

BTW, I ordered my C&S firing pin directly from them so I expect it will be a "fresh one."

Here's a pic of the firing pin.

 

[Charles]

Interesting. The argument here progresses from "just as good as" to "even better than." That's a tough sell.

Hey RedLevel! How's that Vaquero treating you?


After owning dozens of forged guns over the years, I have run into a few that NEEDED some work, and very few that didn't benefit from a little cleaning up. And it's not so much "gritty" as they'll have some little hitches in both the takeup and return, especially with the flash-chromed parts you find on the stainless guns (which are my favorites, btw).

The MIM guns I've owned and handled have been better insofar as there is very little you need to do to improve them.

On the other hand, half the fun of buying an old Smith is getting inside it and cleaning it up!

And the MIM guns DO lack, ...well, something... in their feel. A really slick forged-internal gun has a silkiness, a solidity that the MIM ones don't quite duplicate.

And of course there's the sound... the "thwinkk" of the MIM guns is nowhere near as satisfying as the "clack" of the forged guns.

But when it's time to bust caps... You (well, I guess I should say "I") can get an ultra-light, ultra-smooth, 100% reliable DA pull with less work and more repeatability using a MIM gun.

 

[stantheman86]

My solution is just to own plenty of both

Older ones are definitely shooters and will last forever, but IMO there's no reason to ignore the new ones. They are made with modern technology to eliminate more manufacturing error at a lower production cost. Whether the Smith was made in 1870, 1970, 2010 there were lots of guns that came out of the factory perfect but also a few lemons that slipped out. I recall a story from a guy who bought a "legendary" Colt Python NIB back in the 70's and he returned it to the shop when he discovered it made it out of the factory with no rifling in the bore......doesn't mean ALL of them are bad, just THAT one got through in a massive QC brain fart......

The broken pin is unsettling, then again my 2005 Dodge Magnum came from the factory with two defective front wheel bearings that went out after only 12,000 and about 20,000 for each one, about 100,000 miles or so prior to when I was supposed to have to start worrying about them "wearing out"........sometimes you just get a bad part, be it cars, guns, anything with more than 1 part is subject to errors, faults in manufacture, etc. I don't drive a handbuilt $300,000 Bentley and a $600 S&W is not a one-at-a-time handcrafted $20,000 Korth revolver.....with mass production there will be mistakes.

 

[Mule88]

Ive had a hammer mounted firing pin breaK ON A m-19. so anything can break MIM or forged.

 

[ken158]

I have had more hammer mounted firing pins break than MIM breaks. If you think about it, S&W as well as all the other gun makers are in a good position where as they build and sell stuff that most consumers look at but rarely use... when they have to make a few repairs, so what?

 

[stantheman86]

S&W firing pins can and do break. If I am not mistaken S&W tried to reduce this occurence with the spring-loaded firing pin in later pin-in-hammer revolvers.

The good news is it's far easier to replace the frame mounted pin than to try to replace a hammer mounted pin.

 

[Nightowl]

My brother in law experienced a broken hammer mounted firing pin on his 629-3 or 4 the day after Thanksgiving. Very few rounds fired through it. It is rare, but it happens. By the way, parts for the older guns are getting harder to get. Brownells and Midway were both out.

 

[stantheman86]

I found what works for me......use the MIM guns as shooters and the ones to do "mods" on like spring jobs, etc. and actually have fun with them Keep the older forged part S&W's as occasional shooters and collectibles, enjoy them, don't mess with 'em and they'll be fine. I see no need to beat up my near mint Model 66 2.5" that I've had since it was new in 1989 when I can shoot the daylights out of my 64-7, have just as much fun with it, and truth be told the 64-7 is the better shooting gun.

Ruger fans (I am a Ruger fan as well as a S&W nut) are starting to see the same thing with the DA Six series which ended production in 1988, the parts and service support is virtually nil from Ruger so if you need something you have to search for mostly used parts on GB. In a few years parts for the older S&W's will be priced high and hard to find......has anyone checked out a NOS forged .500 target hammer lately? People are paying close to $100 for these things......

 

[AveragEd]

Great discussion on an interesting topic by several knowledgeable posters. As a recent returnee to S&W shooting and collecting, I'm really appreciating it.

Over the course of the past several months, I've purchased seven new or like-new pre-lock S&W revolvers (two 629 Classics, four 686s and a 66) and one heavily-carried but lightly-shot 64. Only one, a 6.5" 629-5 Classic PP, has the MIM trigger and hammer while a 6.5" 629-3 Classic has the forged pieces. On a casual inspection, the only differences I can SEE are the cut-out area in the back of the trigger and a slightly different profile of the hammer spurs when viewed from the rear. I think I have a decent sense of feel, but I can't tell any difference in that regard.

Both those 629s have frame-mounted firing pins and based upon my rifle and shotgun experience, I've always felt that was a stronger system. There may be some out there, but I'm unable to think of a modern rifle or shotgun with an exposed hammer that has a hammer-mounted firing pin. I have shot as many as 10,000 trap loads a year for many years with a break-open shotgun that has long, fragile-looking, frame-mounted firing pins without ever breaking one, so I have to wonder (perhaps due to lack of knowledge) what all the fuss is about aside from the fact that the newer MIM technology and firing pin mounting are "not how it's always been done."

Thanks again for the informative exchange!

Ed

 

[roaddog28]

I think competetion shooters with 10's and 10's of thousands of rounds on their MIM S&W's would disagree that the parts wear out faster........there are pages of debates on this, many feel MIM is actually a longer wearing part than forged, but I'm sure someone will come in and dispute all of this as usual. There's only about 10 years of "field data" on the MIM guns vs. over 100 years with the forged parts, so it will take some time for something "new" to be accepted, I think.

The early MIM parts had failures in the late 90's -early 2000's when S&W was perfecting this new technology, now they pretty much got it down. MIM parts require no fitting, they just drop in.

This is a "can of worms" topic, because now many people will stop in to this thread to take a shot at the MIM S&W's. I won't add fuel to the fire, I have many older forged part S&W's and new MIM S&W's and I love my MIM guns, all I have to say. They are fantastic shooters.

The frame mounted firing pin, is also a topic used to "bash" new S&W's, although Ruger has used them since the 50's, and they have been used in revolvers since the 1890's by some European gunmakers. But still it's seen as "cheap" by some despite the fact that it's far from a new technology.

The frame mounted pin makes it easier to "tune" the new S&W's since a longer pin, like a Cylinder & Slide extended firing pin, can be dropped in to allow for use of lighter mainsprings with no FTF's. I did it with my 10-14 with a Wilson Combat mainspring, the above mentioned extended pin, and the action is like butter and it shoots like a laser, and I expect it to do so for a very long time.

People who ignore the MIM revolvers are missing out on some excellent shooting and sharp looking guns IMO.

Hi,
Are the extended firing pins hard to install? I have a model 10-14 too and would like to improve my trigger pull like my older Smiths. I have no issues with my model 10. Its as accurate as my older Smiths. My only real complaint is the internal lock hole. I don' use it but its ugly to look out.
Thanks,
Howard

 

[Wayne M]

S&W has been in the MIM business long enough they've got it figured out. Buy the gun and shoot it. I've been trying to wear 686's out(both forged parts and MIM) for a lot of years. Sorry, no luck to report. I really have no prefrence performance wise but will say that the MIM guns are easier to replace parts in......they usually don't require fitting. Now I've never had to replace parts in either but ya gotta have parts, just in case!

 

[stantheman86]

Roaddog let's see some pics of that 10-14! I'm a Model 10 nut and I just like to see pics of other guns, especially the newer ones

Installing the extended pin is simple, you just remove the sideplate, take a set of needle-nose pliers (preferably padded to avoid scratching the retaining pin) and pull the pin out, it comes out easily since the sideplate holds it in. Then push in the firing pin and release it with your finger so it "springs" out of the frame........take the new pin, put the spring over it, and put it back in the hole.......drop the retaining pin back in and it's done!

The Wilson Combat springs and C&S extended firing pin were about the best $30 or so I've spent on upgrading a gun. My 10-14 is one of my favorite range guns now!

 

[jeffrey]

The hammernose broke on my 629-4 MG after only fewer than a hundred rounds of .44 Special. This is my only instance of a broken firing pin, with a fair number of hammer-mounted Smiths over the years and a smaller number of frame-mounted Smiths, Colts (Pythons), and Rugers (Security and Speed Sixes). Smith made it right in short order. Stuff breaks.

 

[stantheman86]

Hammer mounted firing pins have to be done "right" in order not to break. S&W does them right, but that pin is fragile and eventually will weaken and break. Dry firing doesn't help any. A gunsmith told me a firing pin on an older S&W breaks because of side to side movement during firing, if there's a bit of sideplay in the cylinder, the firing pin hits the primer and then the sideplay twists the pin back and forth, and fore and aft if there's endshake, and after 10's of thousands of times it will weaken the pin.

It's Murphy's Law, people abuse and beat on S&W revolvers and the firing pins never break, but that mint Model 29 you baby and take out for a box of .44 Specials once per summer will probably break a pin....

Rossi makes boat anchor revolvers with hammer mounted firing pins, and they are notorious for breaking. They just were never able to get those pins to fit right into the bushing.