Do you know if innards are interchangable?

Innards Interchange Study, pt. 6

N-frame hammer in a K-frame:


L-frame hammer in a K-frame: The hammer is a bit too tall for the frame (hammer nose hits the frame):


The gap between the frame/cylinder locking bolt and the back of the hammer seems OK, but that shouldn't be too surprising as the K- and L-frames share the same size grip-frame:


Conclusion: N-frame and L-frame hammers don't work in K-frames
 
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valkyriekl: Thank you for your efforts in this study........but IMHO, you have way too much free time on your hands. :-) .......... Big Cholla
 
Innards Interchange Study, pt. 7

Valkyriekl,

You're right! There are 4 sizes of forged short action hammers.
What do I do for pennance?

Gil

Well, the forged stuff sure. But the MIM stuff was pretty interesting; just you wait!

K/L-frame MIM hammer in an N-frame:

It actually does fit (with gaps, of course):




I was able to cock the hammer and bring it down into full-lockup:


Even more interestingly, the hammer pushes the firing pin into the frame window:


My conclusion: K/L-frame MIM hammers in an N-frame could work. I'd bet it could actually light off a round (I might try this again later, make up a primer-only casing and try to pop it off in my garage).
 
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Innards Interchange Study, pt. 8 & 9

N-frame MIM hammer in an L-frame:



N-frame MIM hammer in a K-frame:


Conclusion: yup, too big.
 
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Innards Interchange Study, bonus pt.1

I figured that while I was at it, I'd illustrate the differences between MIM and forged K-frame hammers. I brought out my Model 17 no-dash:


Sideplate off:


Side-by-side comparison (MIM on the left, forged on the right):
 
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Innards Interchange Study, bonus pt.2

With the MIM hammer installed in the Model 17, the hammer fits but rests well away from the recoil shield/firing pin:





Attempting to put the lockwork into full-lockup, the hammer stops well short of the firing pin:




And in this design there is no transfer bar, no piece of metal that slides up between the hammer and firing pin to allow the transfer of energy.

So a MIM K-frame hammer won't work in a forged rimfire K-frame gun.
 
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Innards Interchange Study, bonus pt.3

And to complete the experiment, I attempted to put a forged K-frame rimfire hammer in a MIM K-frame rimfire frame, with predictable results:

The hammer 'fits'...:


...but is actually too tall for the frame:


Additionally, I could not cock the hammer, and it was pretty tough to remove it from the frame.

So there it is: it doesn't work.
 
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Innards Interchange Study, conclusion

So in conclusion, the hammers are generally not interchangeable between frames of different sizes.

The exceptions are between MIM hammers for K- and L-frames, and interestingly a MIM K/L-frame hammer installed in a MIM N-frame.

To further confuse the line between MIM and forged parts, S&W is also making forged hammers in the shape of MIM hammers for some of their Performance Center guns, complete with cuts for the internal lock system.
 
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Valkyriekl,

You did a bunch of work to educate me. I much appreciate your efforts.

Reflecting on my revolvers that I changed major innard in, it's mostly been replacing triggers with .265" serrated ones which are my favorite for DA. I ordinarilly don't touch hammers while shooting so there hasn't been much motivation to switch them just to get a different thumb piece.

I'll have to be more carefull about what I post.:o This website surely does force us to learn the details.

Changing topic, are you keeping up your bullseye skills with .22s through the winter?

Thanks again,

Gil
 
valkyriekl: Thank you for your efforts in this study........but IMHO, you have way too much free time on your hands. :-) .......... Big Cholla

It actually took more time to write it up and post than it did to do the study (take the guns apart, try each hammer in each gun, and take pictures, reassemble guns).

Now that I've got gun grease all over my hands and guns, I need to go clean up. Well, I didn't have anything better to do anyways; the range is closed today (and every Tuesday)!
 
valkyriekl said:
To further confuse the line between MIM and forged parts, S&W is also making forged hammers in the shape of MIM hammers for some of their Performance Center guns, complete with cuts for the internal lock system.

Great. now we need to add more descriptive terminology to our hammer lexicon. pre-PC forged hammers? PC fake MIM hammers?

Best Regards,
Gil
 
Valkyriekl,

You did a bunch of work to educate me. I much appreciate your efforts.

Reflecting on my revolvers that I changed major innard in, it's mostly been replacing triggers with .265" serrated ones which are my favorite for DA. I ordinarilly don't touch hammers while shooting so there hasn't been much motivation to switch them just to get a different thumb piece.

For fast DA work, I'm with you on the standard/service .265" serrated triggers (and also either semi-target .312" or standard/service .265" hammers for less mass and faster lock-time, but still with the ability to cock for SA).

For SA work, I prefer the combat .312" smooth trigger, with the face optionally covered with a piece of non-slip skateboard tape (the eagle-eyed can see the black tape on the trigger and grip backstrap here). I also like the .312" semi-target hammer as a good compromise between cocking-surface size and faster lock-time (when comparing between the .265" and .500" hammers).

I dunno what it is, but I don't like the wide .400" or .500" triggers for either DA or SA.

Staying on-topic, the triggers will all interchange between all modern K, L, N, and even X-frames.

Changing topic, are you keeping up your bullseye skills with .22s through the winter?

Thanks again,

Gil

Absolutely! Every time I hit the range (every day except Tuesdays, and maybe Sundays), the first thing I'll do is shoot either a National Match Course or double-NMC (same as NMC, but 2x as many shots at each distance/speed) with my 617. I'm finally climbing back up into my 'normal' range of 95-96% after a long six-month funk where I could barely get 90%. Part of that funk was equipment: somehow I shot out the rifling of the original barrel of my 617, and while the gun was back at S&W for a new barrel I was shooting my Model 17 with iron sights and constantly swapping hammers, triggers and grips trying to find something comfortable (that's my excuse, anyways!).

Here's a picture of the forcing cone of my old 617 barrel. You can see a dark spot at 6'o'clock right where the rifling starts:


The barrel has no lead deposits anywhere and the rifling appears to be pretty clean...except for that one spot. Probing it with a bent paperclip, it felt like a divot. I don't think it's a bulge-spot from a squib; I have had a few squibs in this barrel, but I always stopped shooting immediately and tapped them out.

Whatever the case, the gun with this barrel would always shoot to the right for the first shot, and then the shots would settle around the black (but never produce a tight group)

Part of my funk was physiological: after my high point in July, I went on vacation, did not do any dry-fire practice, and did nothing but rode my bicycle up and down the Outer Banks of North Carolina...so my trigger control disappeared, and my arm muscles had atrophied to the point where holding up that heavy 6" red-dot-topped 617 was tough. In slowfire, I would either have to commit to a shooting within the first 10 seconds of hold or I'd have to abort and put the gun down and reset.

The final part (probably most important part) was psychological: after I peaked, mentally I was at the point where I was taking my performance for granted. When it didn't come back after my vacation, I was mentally trying to catch up while trying to readjust...and basically I was out of gas and getting frustrated.

But yes, I'm getting back into it now; my last three league matches I've consistently scored right around 95% (569/600, 570/600, 572/600) and each time feels better than the last.

How about you? Doing any Bullseye stuff over the winter?
 
Gentlemen,

I very much appreciate the info. I am trying to trade a buddy out of a 686 6" with the hammer mounted firing pin. I really want to have the .500 T/H on it.


Thanks, Karnivore

You can get a .500" target trigger for the 686, no problem.

However, while S&W did make .500" forged target hammers (with HMFP) for the L-frame 686s, they are very rare. I think I've only ever seen one or two, and those were only in pictures - never 'in the flesh'.

MidwayUSA does list a forged L-frame target hammer as being out of stock here.
 
Valkyriekl,

I don't want lighter hammers on k22s for faster lock time. I want a heavy smack on the case rim. I hate alabis. The problem with wide triggers for DA is they obstruct curling the end of your finger around the trigger reducing the leverage you can get.

I have not heard of anyone wearing out a k22 barrel before. It looks like what you refer to as a divot is a gouge or at least is concave rather than a hump but I'm not certain. I suspect over time you weakened a flaw in the steel's crystal structure because ordinary wear that I've seen in forcing cones and rifle throats has been symetrical. In the picture the lower rear edge of the forcing cone looks more rounded off from wear than the opposite side. I wonder if the barrel and charge holes were misaligned and the bullets wore away the lower side where they hit first. Did you ever have alignment checked with a range rod?

Last fall was my first season back at registered indoor .22 bullseye matches after 4 or 5 years. I've not shot outdoor centerfire because the matches are too long a drive. Just to get to a registered .22 league is 2 1/2 hours round trip. The "match" a half hour away isn't registered and doesn't offer any real competition. I stick with shooting whole matches DA with iron sights which I've done at nearly all the matches I've attened since the 70s. I hope to be back to where I left off by spring. I never have turned in a master score but I got up into the high 560s which isn't too bad considering how I do things. I hope to get new glasses and replace the 6" barrel on my 617 no-dash with a N.O.S. 8 3/8" 17 barrel for longer sight radius in time to use them in the current winter league. I made 2nd expert out of 26 shooters last fall. The compitition is also getting better so it's unlikely I'll place differently in the spring.

We've now hijacked this thread to a different continent. I guess I should start reading the compitition forum.

Good night and thanks again.

Gil
 
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valkyriekl said:
[...] while S&W did make .500" forged target hammers (with HMFP) for the L-frame 686s, they are very rare. [...]

Fairly early 8 3/8" 686s with cromed .40" serrated triggers and service hammers are common. Thats probably because S&W did not have wide hammers to go with the wide triggers when they were assembled.

Gil
 
I removed all of the hammers, arranged them side-by-side and took comparison pictures:

Forged hammers: (L-to-R: K-frame, L-frame, N-frame)


Dang, just bought a hammer that was advertised as a "K-Frame" but it doesn't fit - BECAUSE it is for a L-Frame. I did not get a photo of it ahead of time, (but I probably would not of known the difference unti now anyway). Anyone want a brand new stainless forged L-Frame hammer with firing pin? I'm out $40. Oh well, live and learn.


Edit 9-5-11 THANK YOU VM! He had a K-frame hammer and we swapped! Now I've got single action capability! :)
Really, this is what this forum is about, helping S&W addicts!
 
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Dang, just bought a hammer that was advertised as a "K-Frame" but it doesn't fit - BECAUSE it is for a L-Frame. I did not get a photo of it ahead of time, (but I probably would not of known the difference unti now anyway). Anyone want a brand new stainless forged L-Frame hammer with firing pin? I'm out $40. Oh well, live and learn.


AR - sent you a PM
 

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