686 or 66 S&w's MIM or USA

R

Rounder

Inactive
Hi, My LGS has a S&W 686 and a 66. Is there a way to tell by looking at them if they're MIM parts or not? I'll just shoot this at the range at paper for fun so it may not be a big deal, still. TIA
Regards, Rounder
 
Centerfire S&Ws with MIM lockwork have a flat-faced hammer with a floating firing pin mounted inside the frame; the two changes were introduced simultaneously. Older revolvers with traditional forged lockwork have the firing pin mounted on the hammer itself.

Two footnotes:
  • IIRC some newer Performance Center guns and the 686 "Pro Series" have forged lockwork with a floating firing pin. However, as a general rule, firing pin on hammer always equals forged; AFAIK none of the MIM guns have a hammer-mounted firing pin.
  • Rimfire S&Ws have used a flat-faced hammer and a floating firing pin since ca. 1930, but the retention pin for the firing pin is externally visible on these guns, and you aren't asking about rimfire guns anyways. :)
 
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The 66 started to pick up a MIM trigger in the end of the 66-4 run. Just look for an ugly trough in the back of the trigger. Thats a MIM trigger. :) No trough?, forged goodness. Infestation of MIM parts occured with the 66-5.

The 686 picked up a MIM trigger late in the 686-4 run. MIM infestation occured in the 686-5.

Easy tell is what carguychris said. The hammer mounted firing pin. See a hammer mounted firing pin and that is a forged part. Despite the vociferous claims to the contrary by the MIM defenders, S&W couldn't make a MIM hammer with the firing pin installed because MIM wasn't strong enough to hold up. They cracked. Regards 18DAI
 
Judging by the thread title, I should probably clarify that MIM stands for "Metal Injection Molding," not "Made in Mexico."
 
Thanks for the info. I'll be checking for hammer troughs and firing pins. Maybe I should check my Tele to see if it's got Molded Injection Metal. Now I'll have to see if the 686 is better than the 66.
Regards, Rounder
 
At the risk of starting a food fight, who cares? After 99,000 posts on MIM vs. forged I've yet to see any credible evidence that MIM parts are less reliable or more prone to breakage than forged parts. I have owned Smith revolvers with both MIM and forged parts, they perform equally.
 
Rounder wrote -
Thanks for the info. I'll be checking for hammer troughs and firing pins. Maybe I should check my Tele to see if it's got Molded Injection Metal. Now I'll have to see if the 686 is better than the 66.
Click to expand...

The only edge the Model 686 has over the Model 66, is the size of the frame. The L frame is larger, and "fixed" the problem the K frames have with light weight bullets (125gr), and hot loads (flame cutting top straps, premature end shake, and forcing cone erosion).

The MIM discussion, for the most part, is way over hyped. I've owned, and still do, several S&W's made with MIM parts. If I blindfolded you, and let you dry fire them, you could not tell the difference between MIM and non-MIM models. Mine are absolutely reliable, and I trust them with my life.

Any part, forged or MIM, has the possibility of failure. That's the chance you take when making things out of steel.

Buy the one which you like the best, and fits you and your style.
 
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