This nice 45 ACP / 45 Auto Rim revolver is in great shape and works flawlessly in single action, and even most of the time in double action if I'm not firing live ammo. When trying to shoot it DA with live ammo either rimmed or rimless, after the first shot the DA pull will draw the hammer back less than 1/8" and then hang, as in full stop. The cylinder rotates OK, but the hammer stops. When I release the pull the hammer returns down fine.

I have had the side plate off and can't see anything obvious (I'm no S&W gunsmith). Any ideas, or recommendations for a real S&W 'smith?

It may be out of time and that can be polished out as a rule, if not timeing polish it out anyway and replace the hammer spring..Ive worked on S&Ws for many years and they are easy to work on and not complicated...You should see the problem once you get all the pieces out and inspected, also inspect the frame and its runways..Inspect the hammer spring as perhaps its been trimmed at some point and that can cause the problem you mention.

Check with your local police or sheriffs office as they usually have an officer that was sent to gunsmith school for pistols..

Make sure the mainspring tension screw is screwed in all the way. It's located in the front grip strap down low.
Backed out ,,or sometimes shortened,,to give a lighter DA pull. But too much can leave the mainspring W/O enough bow in the spring necessary for proper functioning.
That improper functioning usually shows up as the DA locking up.

...though I can't figure it working OK 'most' of the time w/o ammo and none of the time with ammo after the first shot.

It's worth a look.

If the screw has been shortened,, not uncommon btw,,,you can usually make up the lost length by placing a fired primer (less the anvil) over the end of the screw and betw it and the mainspring. Then tighten it back down all the way.
The small extra length afforded by the primer thickness sill often cure the ill if in fact that's whats doing it.

Thank you both; I will attend to the mainspring and innards and report back.

I would be very careful cycling the revolver with the side plate removed. The pin the hammer rotates on is an axle, not a stud or pin (although S&W calls it a stud). Look at the inside of the side plate, there's a hole that axle fits into when assembled supporting that end of the axle. With the side plate removed you run the risk of breaking the hammer stud off. Also, your 1917 is of the 'old' design. There are no 'new' parts available, only used. When a S&W is out of time, it requires a thicker hand. Then, the extractor has to be fit to the thicker hand. The cylinder stop and hand are unique to the 'old' design (these are the parts that take the most wear), as is the main spring and several other parts. It almost sounds to me like the 'hand-off' from the hammer to the DA sear could be the problem, but I resist guessing at malfunctions of any arm. 'bout gotta' have it in hand to know.

Silvers, thanks for that very clear and appropriate 'heads up'. I have not had this 1917 very long, and one of the things I first noticed about it was a very prominent drag line around the cylinder between the cylinder stop notches. Now that I am taking a much closer look at things it appears that the visible part of the cylinder stop itself has been rather crudely filed on, and that, in combination with your comments, leads me to believe that the cylinder stop may have been replaced at some point. The notches in the cylinder also show slight raised 'lips'.

Today, with the side plate still firmly attached to the revolver, I filled each chamber with a fired 45 AR case (including fired primer) and watched very closely what was happening at both the hammer and the cylinder stop as I cycled the action both in single and double action. Compared to a similar vintage S&W 1905 4th model 38 it is very obvious that the cylinder stop is raising much, much sooner on the 1917 -vs- the 1905.

In single action with the 1917 the stop rises after the cylinder notch is clear, though just barely. In double action the stop pops up again almost before the cylinder moves at all, and will re-lock the cylinder about a third of the time which stops everything. (This is contrary to what I said in my original post about the cylinder rotating OK, my bad)

The timing, as far as getting the cylinder all the way 'round to the correct position before the hammer falls, is great in both single and double action. It's at the beginning of the turning cycle where the problem lies.

So, it appears I have a couple of problems. First, the cylinder stop is rising much too soon in double action. And two, the cylinder stop itself might be just plain wrong.

One other thing I noticed a couple of weeks ago when I was trying to figure out what might be going on - there is nothing under the 'fifth' screw at the front of the trigger guard. Should there be a spring or bumper or maybe some old pocket lint in there?

There should be a spring and plunger under that screw. As much as I don't like to diagnose without having in hand, my guess is the cylinder stop is worn out. That spring and plunger I mentioned is what returns the cylinder stop to its "up" position, where it'd lock into the notches in the cylinder. There's a tongue on the front of the trigger (internally) that engages the cylinder stop to lower it so the cylinder can revolve. At a certain point in the cycle, the stop is released by the trigger and the spring pops it up to engage the coming notch in the cylinder. That contact point on the cylinder stop wears, and the trigger doesn't reliably engage. I hate to suggest just changing out parts without physically examining for myself. gunpartscorp has used parts. As I mentioned previously, there are no new parts. I did repairs for a pawn shop that was near the GS school that I attended. Seems to me the first repair I made was on a S&W K frame that had that cylinder stop problem. That was many yrs ago. The S&W revolvers were well covered in school and I got a few more hrs of instruction from Ron Powers. He really didn't show me anything that hadn't already been covered by the instructors at school, but I got the certificate showing I'd attended the classes he taught. I've got a 629 in the right now with a snapped-off hammer stud, 'cause its owner liked to watch the mechanism 'work' with the side plate off!

I think I'll order a set of cylinder stop parts (stop, plunger and spring) since it appears that Numrich (gunparts) has them all and they're not that expensive. And I'm definitely going to pull the fifth screw again and see if I have missed something or it's true that the plunger and spring are actually gone. 'Gone' would sure explain a lot!

Back in the 80s when I was traveling a lot for work I actually stopped by the old Numrich parts pile just to see it - quite a pile it was, too. Amazing.

Thanks again silvers, you have really helped here!

Steve Meyer

Added: Spring and plunger were indeed in there. I ordered an extra set anyway along with the cylinder stop.

Brownells used to sell a tool for removal/installation of the rebound slide. I'd get 1 if they have any, it'll save time and trouble. The front side plate screw is fit to its position, make sure it goes back to where it came from.

Numrich (gunparts) delivered the parts right on time and comparing the replacement cylinder stop to the old one shows a lot of obvious wear at the release 'lip' on the stop where it contacts the trigger. I'll post a picture or two tomorrow.

Unfortunately the replacement part needs more fitting than I'm confident of doing myself - mainly the 'finger' of the stop that projects through the frame is a bit wider than the slot and the polishing/stoning I have done so far hasn't been enough to get it to clear. There are a couple of other differences in dimensions between the old and replacement stop, and several other internal parts that show quite a bit of wear too, so I'm think it's best to leave it be until I can get it to a knowledgeable 'smith.

I have put it all back together with the old stop in it and it still works fine in SA. That will be good enough for now.

Thanks for all your help!

Pictures of the old cylinder stop (left) and replacement (right). The wear on the lower lip of the slot in the stop (uppermost in the picture) that engages the trigger extension is obvious on the old one. There are a few other differences for sharp eyes, too. The pictures were taken before I stoned the sides of the curved finger on the replacement.

We had one in the shop recently that behaved similarly. It had a worn trigger lever. Make sure the ball end of the lever where it fits in the rebound slide is nice and rounded with no flats. You can make a rebound slide removal tool from a flat blade screw driver. Grind a notch into the blade about 1/16 of an inch from the edge. Hook this notch into the rear of the spring between the spring and the post. Push and lift to control the slide out.

Thanks, I didn't look very closely at the ball end of the trigger lever. I still have an IBM-supplied 'spring hook' much like you describe from my ancient days as a mainframe mechanic - it works well on S&W rebound slides too.

NO metal removal on the "ball' of the cylinder stop. The check should be, "does it fit the notches in the cylinder as it should?". Not, "it won't fit through the window in the frame". That can be fixed, if you make the 'ball' too narrow, that can't(be fixed)!

Gotcha. Terminology difficulty here I think. I have been describing the part of the cylinder stop piece that projects through the frame and actually engages the cylinder notches as the 'finger'. In the first picture above you can even see that the replacement cylinder stop on the right has a fatter 'finger' than the old one. Fitting that finger to the notches in the cylinder makes perfect sense now that you have mentioned it, and if the finger-to-notch fit is correct, but the finger won't fit through the frame slot, changing the shape or size of the frame slot is something I definitely do not want to attempt myself. Cylinder stops are cheap - frames are not.

Fitting a cylinder stop is beyond the capability of most hobby gunsmiths. Metal should only be removed from certain places, otherwise you risk mis-alining cylinder to barrel. That'll spit lead. Years ago, we used to be able to buy oversized cylinder stops for current manufacture S&W revolvers. Not anymore, not from S&W, anyway. We can buy aftermarket oversized, but not S&W manufacture. The reason I believe, they require proper fitting, and you can't just hack off metal anywhere to make it fit. As I said, not done properly cylinder to barrel will not be correct. Possibly making the revolver not safe. Aftermarket oversized is now sold/made by Power Custom, and S&W manufacture oversized only available for factory install or an authorized S&W repair shop. Fitting an obsolete would require the same, I believe. And, that's what you have, obsolete. The 1 Numrich sent looks like crap, but maybe that's all that's available. There are no new parts for your 1917.

Avoid getting over your head....you just have to have a knowledgeable smith to work on these guns...otherwise, you'll have scrap.

Many years ago, I did a lot of this kind of work, but it 's like playing piano...you just have to have hands experience on almost a daily basis.

I'd run it past Hamilton Bowen..his forte is SA. but it would be a place to make inquiry.

Many thanks for all the advice and insights given here. It's pretty obvious to me that, regardless of the great bore condition and decent external finish, this 1917 S&W is just plain worn out inside and well beyond any help I can give it on my own. Whether or not it might be repairable by an expert, the $$ involved will most likely dissuade me from pursuing it further.

Well..about the only gun I can think of that CAN'T be fixed is Remington 740.

Send it to someone knowledgeable to find the options

A worn smith can be real smooth, so don't feel its worn out, I think the s&W is always fixable and when made to work it can be super nice double action..It can be fixed and shouldn't cost too much if the gun is decent to start with...Have you considered sending it to Smith and Wesson for repair...If you are convienced its trash, I might buy it from you and have a shot at it..if you price it right..

Hi Ray,

It's not trash by any means, it's just not reliable in double action. In single action it's a peach and it shoots great - and that's fine by me. I have other more modern revolvers I can practice my double action shooting with.

I doubt that the S&W company would be willing to work on a Model 1917, though I'm sure there are other competent S&W gunsmiths in the U.S. who could get it running in double action without too much trouble - just none very close to where I am in California.

Or maybe it is actually worn out. I picked up a copy of Jerry Kuhnhausen's book "The S&W Revolvers A Shop Manual" to educate myself after all these years, and it has been quite a revelation. Should have got the book years ago since I like older S&W revolvers.

Liveing in calif. can be a gun nuts worst nightmare...Lots of good pistol smith there however..Most of the cops out that way know the best pistol smith as I recall, Ive seen some awesome pistol jobs on Pythons and combat magnums from california in the past...A gun like yours is worth the trouble and cost for sure.

My best guess is the problem is a modified hammer spring, probably cut down for smoothness, a poor modification but used by many..replace the trigger return and hammer springs before you do anything else..