Trigger Job Question

[Justin M]

I have developed what I believe is a fairly straight-forward method to get to a 4lb trigger on a N-Frame S&W.  I'm a pragmatic guy who relishes in routine.  I used a 4" 627 to develop my method so as not to screw up any of my "race" guns.  Once I had the process, I applied it to a couple of 929s and 627/327s.  No issues at all.  I suspect this is very similar to how everyone else does it - no new or novel approach here.  All parts get stoned and/or hit with the Foredom (big Dremel, sometimes it's a Dremel - if that's closer on the bench), an 11lb rebound spring cut down between 1-2 coils, a Wilson mainspring bent to my particular pattern (I've snapped two S&W mainsprings, so I refuse to use them any longer), a X Frame cylinder stop spring, a Cylinder & Slide firing pin (against all recommendations), a snipped firing pin spring, and a 175-200gr "Carmonized" hammer.  All guns, so far, are reliable with Federal 100s - plus or minus a couple ounces of 4lbs.  I usually end up moving the pull weight up to between 5 and 6lbs because I happen, for whatever reason, to shoot better points with a slightly heavier trigger.  

 

So, buddy asked me to "Carmonize" his hammer and get his new (to him) 929 ready for USPSA.  He wants to use Winchester primers, because, um... not sure, but that's his thing, right?  I go about my routine to get to a 4lb trigger figuring I'll get it set up at 4lbs, make sure it's reliable with Federal 100s, then up the mainspring until it reliably fires Winchester primers, and balance out the rebound spring. Gun refuses to reliably fire Federal 100s at 4, 5, 6, ... all the way up to about 10lb.  It'll fire some, but not all.  It'll fire some, but not all Winchester primers at the heavier settings as well.  Of course, match in the morning, because that's how this usually goes, right?!.  I take out my beautiful, super-light "Carmonized" hammer and throw in an Apex hammer and it starts to work, but still at the heavier settings.  Maybe 8lbs give or take.  

 

I'm having hime come back this afternoon to try out an Apex pointy firing pin and to check headspace.  I cannot figure out what else it might be.

 

My questions: 

 

1.  On the Apex pointy pin, why pointed?  All things being equal, will that pin give more reliable ignition than a stock or a similar (rounded or blunt nose) firing pin?  

 

2. What else could be going on here?  There's no drag on the "Carmonized" hammer, the Apex hammer, the firing pin, etc.  Hammer block is laying on bench.  Not more than .002" end shake. Not sure where to look.

 

3.  Unrelated, I think, but still might inform some of this: Why does the Apex .22 hammer have more mass?  If lighter is better for hammers, why does this change from rimfire?

 

[pskys2]

Have you checked to make sure the hammer isn't cracked?

Some have had cracked hammers when too much is taken off or if there might be a weak spot in the metal you weren't expecting.  Hair line cracks can be hard to see also.

Also did it work reliably stock?

Way outside the norm issue, does the fp hole match where the primer is?  Would seem really obvious but weird things do happen.

 

Keep us informed.

 

Apex did an action job at 4 lbs for me on a 625PC.  I never could get used to it, the sweet spot for me is also 5-6 lbs.

At 4 lbs my mind kept telling my finger I was shooting a 1911 and I would fail to release the trigger enough. I know after a few thousand rounds I'd get used to it, but at that weight it just doesn't take much to cause a ftf.  Upping a pound and a half seemed to be a bit of insurance also.

[Toolguy]

1. Don't know about pointed, ask Apex.

 

2. It sounds like the hammer is hitting something in the action that absorbs some of the striking force. The main 2 things I can think of right off are the hammer block and the rebound slide. The hammer block may not be getting all the way down. You can check that by removing it and test firing to see if the problem goes away. The rebound slide may not be getting all the way back, especially if there's a trigger stop. Then the bottom of the hammer could hit the rebound slide just before the top hits the firing pin. You can check that by pulling the trigger, then hold the top of the hammer all the way down on the frame. Then move the trigger front to back and see if there is some free play where the rebound slide is going back behind the hammer.

 

3. The .22 hammer has to be heavier because the rim of the .22 case is harder to dent than a centerfire primer. The primer has one thickness of metal with support far away from where the firing pin hits. The rimfire is 2 thicknesses of metal with a 180 degree bend where the firing pin hits. The bent area lends a good bit of support right where the dent goes.

[alecmc]

5 hours ago, Justin M said:

big Dremel, sometimes it's a Dremel 

 

 

 

No.

[Justin M]

11 minutes ago, alecmc said:

No.

 

I'm not sure I should reply, but I feel I must (and it beats working)... What is that "no" for?  Are you disagreeing that a Foredom is just a big Dremel? 

 

I will be checking out the 929 this afternoon, I hope, to see what I can come up with.  

 

So far, this is what I know:

 

1.  Hammer is not cracked.  I inspected it as best as I could.  Put it under magnification, tested it another gun (627), and - short of magna fluxing it - I believe it to be sound.  

 

2. The hammer was free to move when I installed it.  I checked this several times when the problem first came up.

 

3.  I will check firing pin hole location when I get the gun back.

 

4. I will be checking headspace as well.  This was an issue with my first revolver, a TRR8.

[alecmc]

35 minutes ago, Justin M said:

 

I'm not sure I should reply, but I feel I must (and it beats working)... What is that "no" for?  Are you disagreeing that a Foredom is just a big Dremel? 

 

I will be checking out the 929 this afternoon, I hope, to see what I can come up with.  

 

So far, this is what I know:

 

1.  Hammer is not cracked.  I inspected it as best as I could.  Put it under magnification, tested it another gun (627), and - short of magna fluxing it - I believe it to be sound.  

 

2. The hammer was free to move when I installed it.  I checked this several times when the problem first came up.

 

3.  I will check firing pin hole location when I get the gun back.

 

4. I will be checking headspace as well.  This was an issue with my first revolver, a TRR8.

 

 

I disagree that a dremel belongs anywhere near a revolver trigger job. -- It has its place in bobbing hammers and chamfering cylinders - but " buffing " parts - Nope.

 

And I can only say because i've been there and done that, and had some extremely knowledgeable and reputable mentors properly educate me.

 

Also, In my opinion - there is a difference between making a trigger light, and actually making a trigger smooth. Making a trigger light is easy - a few springs and some federal primers and you have a light trigger. But a smooth responsive trigger is something that takes alot of work. 

 

Again, just my personal opinion - Do whatever works for you and gives you the results you want - more than one way to skin a cat. 

 

As far as your issue - Make sure that the timing is spot on - If your primer strikes are off center they can also cause light strikes. 

 

Also , check to make sure that the hammer is making it's full stroke back, double check to make sure the hammer is actually transitioning off the double action sear , to the double action cam on the hammer , and falling off from there. If you removed too much material from one surface or another it may be falling early and not having it's full potential momentum to light off the primers.

 

 

Best of luck,

Alec

Edited August 6, 2018 by alecmc

[Justin M]

37 minutes ago, alecmc said:

I disagree that a dremel belongs anywhere near a revolver trigger job. -- It has its place in bobbing hammers and chamfering cylinders - but " buffing " parts - Nope.

 

We agree. 

 

37 minutes ago, alecmc said:

Also, In my opinion - there is a difference between making a trigger light, and actually making a trigger smooth. Making a trigger light is easy - a few springs and some federal primers and you have a light trigger. But a smooth responsive trigger is something that takes alot of work. 

 

We are still in agreement.

 

37 minutes ago, alecmc said:

As far as your issue - Make sure that the timing is spot on - If your primer strikes are off center they can also cause light strikes. 

 

Timing is on.  Again, that mess that was my first revolver (TRR8) was a complete shitshow and didn't carry up on something like four or five of chargeholes when I bought it.  I didn't know any better at the time.  Now, it's one of the things that I check immediately.  

 

37 minutes ago, alecmc said:

Also , check to make sure that the hammer is making it's full stroke back, double check to make sure the hammer is actually transitioning off the double action sear , to the double action cam on the hammer , and falling off from there. If you removed too much material from one surface or another it may be falling early and not having it's full potential momentum to light off the primers

 

Now, this might be interesting (...as in "hang him, he's a witch"...), but I have been experimenting with removing the double action cam surface.  Slightly shorter throw for the hammer, sure, but a little more "buffer" before trigger bottoms out.  The first hammer I tried it on was an Apex and it seemed to work well, so I tried it on a couple "Carmonized" hammers.  I've got about two or three thousand rounds thru a 929 set up this way.  

 

The way I look at it, with the problem 929 it should have at least been reliably detonating Federals at some point with a "Carmonized" hammer set so damn heavy.  

 

I'll try a "Carmonized" hammer with the double action cam surface intact (...what, exactly, is the proper name for that?) and see if that produces different results in the problem gun.

 

Thanks.

Edited August 6, 2018 by Justin M

[alecmc]

3 minutes ago, Justin M said:

 

but I have been experimenting with removing the double action cam surface.  

 

 

I'm no engineer , but IMO this is counter intuitive for getting the best possible results.  I cant say 100% but i was under the impression that aftermarket hammers like the Apex and TK have slightly different geometry so that the DA stroke is a touch longer over factory.  More travel, more momentum, better ignition. That whole E=Mc2 thing..or something.

 

From what i've read those short stroke DA triggers were popular back in the day - shorter pull , but much heavier trigger. 

 

You cant have both. 

 

 

[Alaskan454]

3 hours ago, alecmc said:

 

 

I'm no engineer , but IMO this is counter intuitive for getting the best possible results.  I cant say 100% but i was under the impression that aftermarket hammers like the Apex and TK have slightly different geometry so that the DA stroke is a touch longer over factory.  More travel, more momentum, better ignition. That whole E=Mc2 thing..or something.

 

From what i've read those short stroke DA triggers were popular back in the day - shorter pull , but much heavier trigger. 

 

You cant have both. 

 

 

I am an engineer, and I'll say with certainty that unless you did major surgery to alter the geometry of your revolver action, shortening the hammer travel will require a heavier pull.  I experimented with these things myself and have settled on the opposite of your approach for mechanical advantage and firm primer strikes.  I used to run something in the mid 4# range but actually run a 6.5# gun now.  

[Justin M]

12 minutes ago, Alaskan454 said:

I am an engineer, and I'll say with certainty that unless you did major surgery to alter the geometry of your revolver action, shortening the hammer travel will require a heavier pull.  I experimented with these things myself and have settled on the opposite of your approach for mechanical advantage and firm primer strikes.  I used to run something in the mid 4# range but actually run a 6.5# gun now.  

 

I agree with that, however, I don't know what the magnitude of change is.  A degree or two of hammer rotation vs a hammer that has 70% less mass.  The calculus for me is this: Is the slightly heavier pull worth the "extra" room before the trigger comes to a stop worth it.  It seems to be worth it for me - at this point.

 

I didn't get a chance to look at the problem 929 this evening.  Too nice of a day to stay in shop, fired up a scooter and went out for a ride.  Likely tomorrow.  

 

I think, and to be clear - I have about zero revolver experience, that we're discussing a couple different things here: 

 

1. The problem with primer ignition (and trigger pull weight) on the "problem" 929.

 

2. My experimentation with removing the double action "cam" feature on the hammer.

 

I can split the thread, if folks would like to discuss removing the double action "cam" feature.  I think it would be interesting to understand experiments/approaches other people have pursued.

 

[Alaskan454]

52 minutes ago, Justin M said:

 

I agree with that, however, I don't know what the magnitude of change is.  A degree or two of hammer rotation vs a hammer that has 70% less mass.  The calculus for me is this: Is the slightly heavier pull worth the "extra" room before the trigger comes to a stop worth it.  It seems to be worth it for me - at this point.

 

I didn't get a chance to look at the problem 929 this evening.  Too nice of a day to stay in shop, fired up a scooter and went out for a ride.  Likely tomorrow.  

 

I think, and to be clear - I have about zero revolver experience, that we're discussing a couple different things here: 

 

1. The problem with primer ignition (and trigger pull weight) on the "problem" 929.

 

2. My experimentation with removing the double action "cam" feature on the hammer.

 

I can split the thread, if folks would like to discuss removing the double action "cam" feature.  I think it would be interesting to understand experiments/approaches other people have pursued.

 

If you like the result I say try it for a while, everyone has their own personal preferences.  Unless you changed the engagement angles significantly, were talking about changes in the range of ounces.   Two main things appeal to me about have the slightly longer DA pull and a heavier trigger.  The first being more reliable ignition (if everything else remains fixed), and the second being a snappier return.  After increasing my hammer spring tension a touch, I've never had a light strike.   Similarly, it's more tolerant to dirt and grime with the extra hammer spring tension.  I've had it so dirty the cylinder doesn't want to spin free, and it still goes bang every time.

 

As for the rebound spring, in certain circumstances I will death grip my gun to run it faster, or to stabilize it for longer/tighter shots.  That extra spring compression is helpful in both instances.  I have a tendency to short stroke a lightly sprung gun.  I like having some reasonable pressure on the trigger at all times, so the extra spring tension is worth it to me.  

[66L]

11 hours ago, Justin M said:

I can split the thread, if folks would like to discuss removing the double action "cam" feature.  I think it would be interesting to understand experiments/approaches other people have pursued.

 

 

I would like to hear more about this.  I have no idea what this is referring to, but I'm always up for learning something new about revolvers.

[swordfish]

On 8/6/2018 at 9:38 AM, Justin M said:

I have developed what I believe is a fairly straight-forward method to get to a 4lb trigger on a N-Frame S&W.  I'm a pragmatic guy who relishes in routine.  I used a 4" 627 to develop my method so as not to screw up any of my "race" guns.  Once I had the process, I applied it to a couple of 929s and 627/327s.  No issues at all.  I suspect this is very similar to how everyone else does it - no new or novel approach here.  All parts get stoned and/or hit with the Foredom (big Dremel, sometimes it's a Dremel - if that's closer on the bench), an 11lb rebound spring cut down between 1-2 coils, a Wilson mainspring bent to my particular pattern (I've snapped two S&W mainsprings, so I refuse to use them any longer), a X Frame cylinder stop spring, a Cylinder & Slide firing pin (against all recommendations), a snipped firing pin spring, and a 175-200gr "Carmonized" hammer.  All guns, so far, are reliable with Federal 100s - plus or minus a couple ounces of 4lbs.  I usually end up moving the pull weight up to between 5 and 6lbs because I happen, for whatever reason, to shoot better points with a slightly heavier trigger.  

 

So, buddy asked me to "Carmonize" his hammer and get his new (to him) 929 ready for USPSA.  He wants to use Winchester primers, because, um... not sure, but that's his thing, right?  I go about my routine to get to a 4lb trigger figuring I'll get it set up at 4lbs, make sure it's reliable with Federal 100s, then up the mainspring until it reliably fires Winchester primers, and balance out the rebound spring. Gun refuses to reliably fire Federal 100s at 4, 5, 6, ... all the way up to about 10lb.  It'll fire some, but not all.  It'll fire some, but not all Winchester primers at the heavier settings as well.  Of course, match in the morning, because that's how this usually goes, right?!.  I take out my beautiful, super-light "Carmonized" hammer and throw in an Apex hammer and it starts to work, but still at the heavier settings.  Maybe 8lbs give or take.  

 

I'm having hime come back this afternoon to try out an Apex pointy firing pin and to check headspace.  I cannot figure out what else it might be.

 

My questions: 

 

1.  On the Apex pointy pin, why pointed?  All things being equal, will that pin give more reliable ignition than a stock or a similar (rounded or blunt nose) firing pin?  

 

2. What else could be going on here?  There's no drag on the "Carmonized" hammer, the Apex hammer, the firing pin, etc.  Hammer block is laying on bench.  Not more than .002" end shake. Not sure where to look.

 

3.  Unrelated, I think, but still might inform some of this: Why does the Apex .22 hammer have more mass?  If lighter is better for hammers, why does this change from rimfire?

 

Man I'm looking and I can't find a different part number for the X frame cylinder stop springs compared to any other guns. What's the difference and where do I find one?

[alecmc]

12 hours ago, swordfish said:

Man I'm looking and I can't find a different part number for the X frame cylinder stop springs compared to any other guns. What's the difference and where do I find one?

 

You probably talking about the Extra power Cyl stop springs, you can get them at Wolff Springs here:

 

https://www.gunsprings.com/SMITH & WESSON/K, L, & N FRAME/cID3/mID58/dID264#448

 

I wouldn't bother unless you are trying to alleviate some form of cylinder skipping. 

[jhgtyre]

I moved some comments from here to the Vendor Tent area.  We don't discuss purchasing products, or selling them, outside the Classifieds or the Vendor area.

[Carmoney]

Not 100% sure about the TK hammer, but the Apex hammer does not have a longer hammer throw.  Same arc of travel, same basic geometry as a factory stock hammer.

[Gomar83]

Is there any notable difference between the Apex hammer and the TK skeleton hammer as far as quality, fitting, or any pros or cons? 

[MWP]

16 hours ago, Gomar83 said:

Is there any notable difference between the Apex hammer and the TK skeleton hammer as far as quality, fitting, or any pros or cons? 

TK claims on their website to be 19% lighter than competitors. Considering they have a big hole in the middle of it I would think that’s about right. 

 

Quality- they’re both top notch. Fitting-they both will require some attention, neither are drop in. 

 

I cant think of a pro or con one way or another other than the weight. The gun being smooth is much more important than the hammer weight or really the trigger weight. 

[BallisticianX]

To not get good ignition until 8-10lbs with a federal primer means theres an issue with excessive  headspace, severe hammer drag after release, firing pin channel obstruction,  or timing issue. Also the whole holy grail of having a 4.5 lb double action is not all that wonderful. To achieve that your mainspring is so light that the slightest little thing off causes FTF. Also you have to lighten the rebound spring so much your making the reset lazy and lose the feedback to your finger. I agree with a couple other posters, anything below 6 lb becomes more of a disadvantage. How smooth and free of resistance you work the action is more important. A well worked 6lb DA will feel lighter than it is while more crisp and responsive than a lazy 4.5lb action! And finally....only thing a dremel tool is used for on a revolver is to bob a hammer or contour the trigger face. Any action work is done by controlled dexterity of the hand with india stones and arkansas stones.  

Edited January 17, 2019 by BallisticianX

[pete627]

I always figured the "pointed" firing pin allowed it to concentrate it's force on a smaller area ... (making it easier to make a dent ... we only need a dent ... doesn't have to be a large diameter dent).

However ... I tried an Apex pin when I originally did my 627 and couldn't get near 6lbs (7 was safe). I realize there may have been something unique/wrong with my pin (at the time they were selling two different versions of S&W pins ... I could have easily done something air headed ... ) but ...

I put my factory pin back in and got down to low 5's no problem. I bumped back up to 5lb 12oz and been there ever since (except for a short period  when I panicked due to a few bent moon clips).  

This was my target area so I never bothered to put the Apex back in to see what was going on or if I had erroneously blamed it for the problem. 

[MikeyScuba]

We took the extended firing pins out. 

[Gomar83]

So my question is if a few of you gentlemen have tried extended firing pins and then removed them so what was the desired results that you were looking for upon installation and then the reason for removal? Are the extended firing pins supposed to be a fix all for a light strike problem?

[Toolguy]

The extended firing pins were origingally invented to make up for variations in primer seating depth, rim thickness, moon clip variations, endshake, and whatever other variations from perfect engineering drawings might arise. This was during a time when the factory pins were running a little on the short side, so you had to have a really heavy hammer blow to set off primers in the average gun. The original intent was to get a pin long enough to have a decent action under a variety of normal slight variations in gun and ammo. The shortest reliable pin length I've seen is .495, which is the longest factory pin I've measured, with most of them being from ..482 to .485. I prefer a pin in the .500 to .505 range. I like the Power Custom firing pins.

 

If every gun was exactly to drawing specs and every ammo had flush seated primers (not .010 below flush), then we wouldn't need extended firing pins. In the real world, there are small variations in everything, so the extended pins are good insurance. Some gun and ammo combinations don't need an extended pin because they vary towards print dimensions. Some guns and ammo need an extended pin because they vary away from print dimensions.

[Gomar83]

For dry fire purposes will snap caps hold up to extended firing pin or is there something that will hold up better? 

[alecmc]

1 hour ago, Gomar83 said:

For dry fire purposes will snap caps hold up to extended firing pin or is there something that will hold up better? 

 

i've always just used empty shell casings, ( or shhhh ! dont tell anybody - a empty chamber ! *GASP* ) and have never had issues with quality firing pins. 

 

You can make your own snap caps, if you reload. Just dont deprime the case when sizing, and dont put powder in when loading a batch of dummy rounds. Ive even seem some people go as far as taking the primer out and shoving a bit of pencil eraser in the primer pocket, or filling the primer pocket cavity with hot glue or something to absorb the pin strike.