Hi group. I recently picked up a very nice 645 on Gunbroker that I have a few questions about.

First, it has what appears to be a trigger stop which is pictured below. I have never seen a trigger stop on a 645 unless its a 745. Can anyone tell if this is factory or if it was added?



Second, when I dry fire it in double or single action, the hammer will very often strike the firing pin then bounce back to half cock. Unless I have an empty casing in the chamber, then it functions normally. This only happens during dry firing. With live ammo it works perfectly. It goes off every time and does not malfunction. I have a slightly older 645 that does not do this at all. Has anyone else experienced this?

Third, the magazines are the kind with the orange follower and the flat metal base plate. They are not marked S&W, but I know they are factory mags. They do not have the black plastic base plate like the ones that came with my slightly older 645. These are marked S&W. Does anyone know which type of mag came first?

Fourth, the safety on the right side of the slide has some play and moves up and down a little bit. The phillips head screw it tight, but it still moves. I have read that some 645s are like this. However, my slightly older 645 does not have this problem. Does any one know if there is a way to fix this or should I just not worry about it?

Thanks in advance!

Weird with the stop. Mine does not have that. As for the right side safery lever, my very early 645 came to me pre owned with the 4506 levers. Big improvement. As for the rest, others here will help you. Enjoy. GARY

The trigger over-travel stop is definitely not original but it looks very well done and if it were my 645 I would be very happy to have it. The flat metal base plate magazines with orange follower are original to the Model 645. The hammer bounce-back is something I have seen happen before and to the best of my knowledge, doesn't otherwise affect anything.

The sloppy right side paddle would certainly annoy me also, I don't know if there is a fix.

Interesting trigger stop, like others said looks well done.
Not to hijack thread, but does anyone know approximately when S&W changed from the metal followers in the mags to the orange plastic ones?

My guess is that it varied wildly like many S&W "updated parts" over time. Most of the 745's I've ever seen have the metal follower magazines and the 745 was made from 1984 to 1988.

It's been my experience that magazines with:
--metal floor plate
--plastic floor plate
--metal follower
--orange, black, yellower plasic follower

...all work just as well as each other in my 745's, 845 and 4566TSW.

90% of the above pistols have eaten 230gr Hardball, but my 745's have had a nice diet of 200gr plated flat point and my 845 has eaten some 185gr JHP, 200gr plated FP and 200gr LSWC.

All my magazines don't seem to notice that some are 15-20 years older than others.

While I am aware that S&W ran in to some .45cal magazine problems (in the 4516, I think?), my guess is that the variation we have seen over the years was mostly a supplier induced change, and not necessarily geared toward an improvement. Just my experience, a drop in the bucket across the long success of S&W .45 cal 2nd and 3rd Gen pistols.

i didnt know they had metal followers. Mine have black plastic followers and orange plastic followers.

That trigger stop is not something that was done when i was building these in the late 80's. Something is strange about it, looks like it was inserted from the trigger side rather than from the mag side as on a Mod 52. I'm curious to know what it looks like from the mag side. Any pics would be appreciated.

Hey donk52, was the 645 stamped with a builder ID number as the 52 pistol was? What's the chance that the OP has the original builder of his gun commenting in this discussion?

Stamp should be in the same spot as the 52, bottom of mag well.

What was your number,donk? My 645 is either 6 or 9 depending which way is up.

I used C or 0 on the 52's. Other autos I used 0

Someone has tried to “accurize” it in the past. The hammer bounce back is evident of someone over lightening the mainspring in hope of dropping the trigger pull weight.

I had one of the first ones issued to me when they came out and I remember it having an orange colored magazine follower, then latter a yellow one. The original mags had a metal floorplate with a small metal tab you had to bend up with a screwdriver blade to disassemble. I don’t remember the plastic floorplates until the 4506 came along. I do remember the rangemasters collecting our old mags and issuing us new ones through an exchange program with Smith.

During my time with the S/O I was issued; a 645, 4506, 4506-1 (along with a CS45), 4566 and an M&P 45. Of all of them, the 645 was the most problematic, having broken three times during qualifications and was least accurate of the full size guns. The 4506-1 was the most accurate and saved my life once. I kept it.

I was happy to see the 645 go and had no desire to purchase my old gun when we upgraded. Now I kind of wish I had.

I suggest you order and install a new mainspring and recoil spring from Wolfe, that will solve the hammer bounce issue. As you probably know, Smith no longer supports this model or has replacement parts. The 645 was the only one in that series with a half cock notch on the hammer. I understand it is hard on the gun to engage the safety when the hammer is at half cock. Good luck.

Thanks for the responses. I just ordered a new mainspring and recoil spring. Can someone please post a link or instructions on how to properly detail strip this pistol to replace the main spring? I cant seem to find it myself. Thanks again.

Well I guess all I really need to know is how to replace the hammer/main spring. I assume I first remove the grips, knock out the pin at the heel of the main spring housing, remove the mainspring housing, swap out the spring and then reassemble in reverse order. Am I correct?

I would have to think the magazine with the metal follower came first because magazines made for semi-auto pistols since the first ones came out, had metal followers. S&W was just following tradition. Soon bean-counters became involved in the production and made a discovery it was cheaper to make the follower from plastic than stainless steel and the followers became plastic. Also the same bean-counters, as a cost cutting measure, probably dropped the black plastic bases from the mags. They figured, if the customer wants a protective cover on the base of their magazines, let them put it on the magazine.

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Bill

For those who are curious about the trigger stop, here are pics from the mag well.

as far as your safety, it will have some movement from side to side. normal. if the lever is falling down, than your need to replace the plunger and spring in the safety body.

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viking

Hey guys. I just removed the hammer springs from both of my 645s and Mike is right. The one with the hammer bounce has a shorter lighter spring than my other one. I traded springs and the hammer bounce disappeared. I'm very happy I ordered the replacement from Wolff. I also ordered a factory original spring from Numrich just to have one. I went ahead ordered new factory screws for my older 645 as the previous owner chewed them up a little.

Now if I can only figure out a way to tighten up the right safety lever. It only has a little play up and down, but I would still like it tight like on my other 645.

I love my 645.

I've shot it fast. Shot it slow. Shot it dirty. Shot it good. Shot it bad. Handed it to a 100lb girl who'd never shot a gun before... never any kind of an issue. I also find it has "same hole" accuracy potential, though the feel/break of the trigger does present a bit of "learning curve."

With the Pachmayr grips, I honestly think the 645 trumps the third gen 45s as far as feel. The FBI palm swell grips with talon grip tape come close... but the 645 with the Pachs still feels better to me.

My right side safety falls off. Even with blue Loctite. I just gave up on it. It has the Philips screw... is the hex screw any better?

I believe my 645 is an earlier model--it has squared off grip screw bushings, which I recall was an indicator of an earlier model... maybe.

I carry it in a shoulder holster in cool weather. Honestly it doesn't feel bad IWB because it's so thin. As long as you can hide the grip.

This is why I would only use factory springs in any gun I own. No aftermarket ****. GARY.

Can't say that I would use only factory springs as Wolffe and a few others make springs that are equal to or even exceed the quality and durability of factory springs. In the S&W pistols, I would stick with the factory weight ratings. I'm not a fan of heavier recoil springs nor lighter hammer or trigger springs.

Years ago I put a Wolff recoil spring in my Sig 220. Compared it with the factory spring. 2 mags side by side, & the Wolff spring went in the trash. Also, it was not crimped at the end to hang onto the recoil rod like the factory spring. Learned my lesson. Factory, or nothing. GARY