Hello. I have recently acquired a 625 Model of 1989 pre-lock. It has the hammer mounted firing pin. I also own a PC 627 with the frame-mounted firing pin. What was S&W's reason for going to the frame mounted firing pin? What are the advantages or disadvantages? Thanks.

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"I'm just a dog chasing cars."

Hello. I have recently acquired a 625 Model of 1989 pre-lock. It has the hammer mounted firing pin. I also own a PC 627 with the frame-mounted firing pin. What was S&W's reason for going to the frame mounted firing pin? What are the advantages or disadvantages? Thanks.

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"I'm just a dog chasing cars."

Someone feel free to chime in and correct me if I am wrong here, but the reason the hammer mounted firing pins were changed to the frame mounted firing pins was for liability. If was hammer was cocked on the old school type firing pins, and the hammer was to fall w/o the trigger being pulled, it would fire. The new style eliminates this by using a a different method....someone else might be able to explain this better. However, I do know the old ones were able to get a much better action job done on them for the reason the firing pin didn't need to strike the primer as hard to make ignition....you'll notice most PPC shooters prefer the old model 64's for this reason.

I don't know what drove the change. But I do know that what you have stated as the reason for the change is wrong. Very wrong.

S&W revovlers since the mid 40s have had a hammer block safety that prevents the hammer from falling far enough for the firing pin to reach the primer UNLESS the hammer was released by the trigger.

I think the reason why the firing pin was moved to the frame is quite simple, to enable dry firing the pistol without as much risk of damage. One rule that I have always had drummed into me is that you DO NOT dry fire a revolver with a hammer mounted firing pin unless you have it loaded with snap caps. Most likely because an unrestrained firing pin would lead to the retaining pin fracturing. Now that the firint pin has been moved to the frame, there is probably a greatly reduced risk of damage to the firing pin or it's retention.

All of the 22's have frame mount pins, has worked great for 50+ years. Now they only have one hammer and one firing pin in the "K" frame. Plus with the MIM part is another reason for the change. Operates the same, easy to produce, less parts to stock. Easier all the way around.

One thing I have heard is that S&W made the change when they started using MIM parts. The reasoning being that they could not make a firing pin mounted on the hammer using the MIM process that would not fracture. But I do not know if this is true. Honestly, I cannot see an advantage or disadvantage of one over the other. In all three of my S&W revolvers (one hammer-mounted firing pin, two frame-mounted firing pin), the bullets always go bang. I am just curious as to S&W's reasoning.

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"I'm just a dog chasing cars."

In reality, the FMFP's are more likely to break during dry firing than the old ones. When SW first went to that design, I called the factory and talked to a SW gunsmith and he said that you would have to fire it millions of times to break it.

I don't know if that is still SW's position, I suspect not. I use snap caps with them for dry firing just to be safe.

Cost savings.

According to Brian Pearce of Handloader Magazine, (Handloader 241 pg. 33 at the bottom) the pin was changed to a frame mounted design to help eliminate primer flow that was known to happen with full power loads and sometimes tie up the cylinder. (rare)

Frame mounted = less primer flow issues

Hammer mounted = better igntion due to a heavier blow given the primer (better for primers with hard cups) also better for light action jobs.

They did it just to p!ss me off
If I'd a wanted a revolver with a frame mounted firing pin I would'a bought a $&^#%@ Ruger.

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Forum consigliere

+100 Just cause I know why they did it, don't mean I like that they did it.

Your all wrong, so very wrong. Truth be told, I talked to the folks up in Springfield about this very thing.

We decided that they needed to change to a frame mounted firing pin so ya'll would write about the why's and where for's of the change and how everyone else is so very wrong and I would have something to read....

Thanks fellers........

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Slim, U.S. Army, Ret.

The model 17 has the frame mounted pin and no one complains. Jerry Miculek shoots revolvers (very well I might add) with frame mounted pins and seems to do well. All my competition guns have frame mounted firing pins, they all work. My 1911 Colt basically has a frame mounted pin, it works. I don't think it is a big deal

Cost and liability----that's why manufacturer's make changes. It must be cheaper, and they started converting their revolvers to the hammer block safeties so we would not sue them if the gun went bang when it shouldn't (like when someone has butterfingers and drops it).

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Chris K