Smith has had a known issue with light strikes in the 617, contact them and they will fix it free of charge. Usually they install a longer firing pin. Can you show us some cases with strike marks? I was not happy with mine until I recut the forcing cone, it was a scattergun and now a tack driver. Their QA is sadly lacking. I have several S&W revolvers of various ages and the ones made in the 1970's had their own set of teething problems. I took a two week NRA Armorer's course in 1982 so I could do my own maintenance and minor repair work.

 

I just fired these 10. All fired on the DA first hit, those indentations are on the bottom of the cases. I then rotated them and dry fired them DA on the opposite sides. This is with a fired spp minus the anvil on the end of the strain screw with it one quarter turn out from tight. The boot grips are from my N frame, they almost fit.

 

I had the same problem.
S&W said to send it in.
They fixed, no problem.

 

Mine spits occasionally too. Did yours? I hate how it sounds like a thrashing machine and the hollow tinny noise when the hammer drops. I have a couple pre model 10s that hardly make a sound when cycling and are smooth as can be.

 

what causes that hollow tiny sound? Mine has it too.

 

Backing out the strain screw isn't a good idea, if you are looking to lighten the D/A pull you polish the rebound slide and the walls of the frame where the hammer contacts it at the pivot pin, and installing a lighter rebound slide spring from Wolff. Mine spit all the time, owing to the crappy forcing cone. Here are pics of it before and after I re-cut it. No more spitting and it's very accurate now.
Before:

After:

 

You’re too far away ‘ol shooter, I was going to swing by and have you fix my forcing cone. I emailed S&W so lets see what they say.

 

Good idea, if you tell them your issues they should make it right. Too bad they don't do it right the first time around.

 

I've near owned every 617 variant ever built at one point in my collecting days. (Every Dash number and barrel length.) I never had a failure in any of them. Don't over think the mim parts and such,.. it all works as designed if left alone. In this case, my bet is that it was a used gun? If so, somebody likely shortened the original strain screw to get a lighter trigger ( and or replaced springs to do the same.) First test is just to add a shim in-between the screw and leaf spring. ( A spent primer works great there.) If it was new, and does need to go back to SW, ask them to do a trigger job for your troubles. They are pretty good. p.s. If you dislike the gun completely, sell it and find a Ruger GP100-22.

 

Standard length round butt strain screw under head dimension = .380” (.505” OAL)

 

I had 71 S&Ws. Had two 617s both of them did light strikes at random. Had no spitting issues. Both guns taken on trade, like new. I’ve never bought a stainless S&W new. Actually they would have to be a steal before I would buy one. Both guns were dry as a bone, lubed they both had drastic decrease in light strikes. Still what I call aggravating.
I don’t keep anything that has MIM parts. The cheerleaders for MIM point out that tolerances make them drop in, saving fitting cost. I don’t care what brand it is, I’m not interested in even looking at it for new purchase. I’ve got several 17s and pre 17s, smooth as glass, thousands of rounds up the pipe. I’m sure my great grandkids will still be shooting them years from now.
I don’t think revolvers have much of a future. To expensive to manufacture. The new ones are getting bad reps and cost more than pistols. The older model revolvers are already sought after and I don’t mean antiques. S&W, Ruger & Colt are all in demand as shooters.

 

I've never had any light strike issues with either my 617 or 648. In fact, it was just the opposite. I installed Wolff standard weight Power Rib mainsprings and 14lb rebound springs in both of them and ordered longer square butt strain screws from GunGarage and fit them to length. Lighter, smoother pulls in both SA and DA and still no problems with light strikes.

 

I have had several pre 17's, 17's and 617's. I have never had a fail to fire any ammo. But all have been factory original. I never felt the need to put lighter springs in. I really don't get why the need to do it. I have polished up the rebound slide and the surface area where it rides on on a few 617's and made it much smoother.
If I bought a 617 that didn't fire I would buy all new factory springs and go from there before I did any else. I have bought a few that have had the strain screw shortened. I replaced them and everything is good.

 

I have a 1964 K22 that I got NIB on a trade at LGS. It is still running original parts and springs and the side plate has never been off. Thousands up the pipe, still tight and smooth as glass. There was a period in my life I carried it almost everyday and hardly a week went by that I didn’t burn at least 50 thru it. This was farm duty no anti personnel. The bluing is thin, no finish left on grips and I wouldn’t change it one bit.

 

As I’ve said I am a tinkerer so I’ve been in my 617-6 revolver but haven’t done anything I can’t undo. I swapped the mim trigger and hammer out for old S&W parts. I had to reshape the top and face of the old K22 .22 hammer. But was still having occasional ftf that would fire on the second hit. Got to looking at the firing pin. Duh, I lost the retaining pin so had to make another. Thing popped off my forceps and totally vanished. Initially the fp was bottoming out on the fp spring so I found another spring in my spring box and shortened it. But then it was bottoming out on the retaining pin so I extended the pin notch to the rear a little more. Pushing with a punch I have a lot more fp coming through the frame now. Just fired 40 with no ftf’s. It’s just not as slick as I want it yet.
Setback- Just tried it without the fired primer under the strain screw and had several ftf. My K22 hammer’s nose/face is still a little longer than the 617 hammer’s face so I’m wondering about taking some more off the face of the K22 hammer which will increase the amount of rotation which should increase the amount of energy the hammer transfers to the firing pin. Try that tomorrow am before it gets hot in my shop.

 

I’ve done good bit of S&W revolver work. I will say I have never put old model parts in MIM gun. I have small horde of NIB S&W parts for MIM generation revolvers. I think I only have one MIM gun left in trade pile. When it goes I’ll get rid of parts. I’m thinning down and going to phase out of even taking MIMs of any manf. on trade.

 

I recently sent a new S&W revolver back to the mothership for warranty work. The trigger pull was horrible. It came back the other day with a perfect trigger. The repair notes stated "replaced hammer." I think when MIM parts are good, they are just fine. The original hammer obviously had a manufacturing problem. The replacement was great. I doubt any of the trained monkey part replacers at S&W did any fitting or stoning.

 

A solid steel hammer has to weigh more than a mim hammer with all the hollowed out areas in it. A heavier hammer should strike the fp harder than a light one. That was my logic in replacing it.

 

If you think about it a lighter faster hammer could deliver as much impact as a slower heavier hammer.

 

I moved the notch back a little on the firing pin to make it extend farther into the frame when struck. I also found a spring that fit and shortened it as the fp was also bottoming out on the spring. Swapped out the trigger with another and what a difference. I flattened out a .22 case and put that under the strain screw instead of the fired primer. Just did 19/20 so not quite 100%. Might shorten the nose on the K22 hammer a little more as it’s still longer than the mim hammer’s nose.

 

I've tried the stock hammer, lightened hammer and the new Apex Mass Drive hammer in my 617s. Stock and my DA pull is around 10 - 11 pounds and will ignite just about any ammo I've tested.

Using a very light hammer I can get away with 7 pounds and bust most 22s but not CCI. I use Federals in this gun and Remington Bucket Of Bullets. I've been shooting Steel Challenge with this setup for about a year.

The nice guys at Apex exchanged my light hammer for their new Mass Drive and it allows me to go to 6.5 - 7 pounds DA with 100% ignition.

Just what I've found in my 617.

 

I guess I am lucky because my 617-6 has worked flawlessly since I got it. I replaced the grips and put in a target hammer (very much recommend), and its very comfortable to shoot single action.

I attempted to install the reduced power main spring from Wolff so I could shoot double action with my arthritic hands. Sure enough, the pull was dramatically reduced, but it also had a very light hammer strike that I have no confidence will be enough to shoot with. I wish there was a spring I could get that is halfway between the factory spring and the reduced power one, because that would be perfect.

 

I guess I am lucky because my 617-6 has worked flawlessly since I got it. I replaced the grips and put in a target hammer (very much recommend), and its very comfortable to shoot single action.

I attempted to install the reduced power main spring from Wolff so I could shoot double action with my arthritic hands. Sure enough, the pull was dramatically reduced, but it also had a very light hammer strike that I have no confidence will be enough to shoot with. I wish there was a spring I could get that is halfway between the factory spring and the reduced power one, because that would be perfect.

Try the factory spring and back the strain screw out until you have it where you like it. measure the distance out from the frame. Get a replacement strain screw and cut it down the measurement you took and you have what you want. I don't think you can find a stainless strain screw so buy a blued one. Save the factory strain screw so you can make it a factory set up so if and when you sell it.

 

I get 8X32 hex head screws from McMaster. They have a red adhesive added to keep the screws in place but are easily moved when you want to tune your gun.

I have a few set screws from Smith & Wesson but the hex heads are much easier to work with. With the hex heads you can produce as much tension on the mainspring as you want, where the stock set screws can only go in so far.

I just finished reaming my chambers with a finishing reamer from Clymer that I bought from Brownells. If you fire enough rounds they get sticky and you have to really hit the ejector rod. Reaming the cylinders helps eliminate that. Sunday I ran 40 reloads and didn't have to clean the chambers once.

 

I did some radical modding to my 617 using a coiled recoil spring from my Thompson 1927a1 build and came up with this idea. Built a similar one for a Winchester/uberti 1873 carbine a couple years ago. So far I’ve found it reliable with Norma .22 and Winchester M22 but still occasional ftf’s with Federals 550. I might do another more refined bearing unit, try to make it truer. The circle is a piece of teflon, there is a small bearing in the saddle, the saddle is Jbwelded to a small piece of steel that is 5x40 threaded. The rod is also 5x40 threaded. Hammer, trigger and cylinder stop are old school steel parts.

 

Wow…. That one really screams “Why?”

 

Very nice, well conceived and good machining.
WHY !
Was there something wrong with the flat spring with stirrup that Smith and Wesson has used since time immemorial,
does your retro have a spring tension adjuster You must be aware that Smith uses the coil spring in most J frame revolvers and it works well.
Please tells us WHY.

S/SP

 

You did well. I had one done to my 625 many years ago by Charlie Prest, the guy that created the first 8 shot revolver for ICORE competition. Charlie wanted to see how it worked and it was great. Lighter action and more reliable ignition.

Hope yours works out for you.