After asking a lot of questions and doing a lot research I finally built up the guts to install the Apex Evolution IV Revolver Hammer Kit in my 327 PC 2”. The manufacturer states that 90% of the time no fitting is required and lucky for me that was my experience as well.

The kit included the hammer, sear, stirrup, rebound spring and firing pin. The mainspring remains stock. This was my first time opening a S&W revolver so I took my time and referenced an armorers video step by step. Everything went as expected and I am very happy with the results.

Next step is to get it out on the range and perform some reliability testing with a variety of ammo. I‘m hoping for no surprises there as the mainspring is stock and the strain screw is fully seated. But we shall see.

I figured I’d post my experience here in case someone else interested in this modification might find it useful.

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How is the trigger pull?

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The trigger pull feels much lighter and very smooth. The kit comes with a competition and a duty/cary rebound spring. I installed the later.

So the apex hammer also has a single action sear? I have almost bought one to mess with a few times but I’ve yet to handle one

On the Apex website they state “Designed using the same pinned sear and stirrup found on the Performance Center hammer...” Here is a pic of the hammer before I installed it.

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Thanks for posting this. I've got a 3" 64 that I've been dying to convert to DAO as i like to carry it. I've considered purchasing this hammer setuo from Apex. Your review has peaked my curiosity!

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I really want one of these now.

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That whole package looks pretty sharp. I love how the hammer sits flush to the frame. Who makes those grips?

They are Hogue bantam in Kingwood.

I may have to try them. I have the original grips but they are too long. I bought some badger grips. They feel great until I shoot 100 rounds and they rub my thumb knuckle wrong. I just got a pair of pacmayr diamond pro grips. The fit is poor and they are thick. Havent shot with them on yet.

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Range Report:

Took my 327 to the range yesterday to begin reliability testing. The trigger felt not only lighter but very short and smooth. I did experience light primer strikes at an average of about 1 out of 8 so I would say this test was a fail. See ammo used below.

Speer Lawman 158gr TMJ 38 Special (24 rounds 3 FTF)
Fiocchi 142gr FMJ 357 Magnum (24 rounds 3 FTF)
Speer 135gr JHP short barrel 357 (4 rounds 0 FTF)

After observing the light primer strikes I left the range and called Apex tactical customer service. I was pleasantly surprised I got someone on the phone in a matter of minutes who was more than willing to provide me assistance. They requested some pictures of the install via emailed and suggested I try to reinstall the factory firing pin return spring. So I opened up the 327 again, took the pics and swapped back in the factory fp spring.

Range Report (take 2): Improvement

Went back to the range and bought another box of the Speer 158gr and shot the rest of the ammo bought earlier in the day. All in all I had 2 FTF (1 38, 1 357) in about 100 rounds. Still a fail of course but moving in the right direction.

I sent my findings to Apex as requested and look forward to some opinions from them on where to start troubleshooting.

Disappointed? A little bit. Giving up? Not a chance.

I installed this kit specifically for the DAO hammer and not for a lighter trigger. It still has the stock mainspring and the strain screw is fully seated. However the trigger feels extremely lighter then it needs to be which I can only attribute to the lighter rebound spring and the difference in the geometry of the new hammer.

My thought from here are:

1. Reinstall the stock rebound spring. I don’t think this would affect ignition but easy to try.

2. Fit a longer strain screw. I believe this would increase the trigger pull and improve ignition. Not sure if this is done regularly?

3. Install stronger mainspring. Do they sell springs heavier than stock?

I obviously have plenty of learning and thinking to do as I wait to hear back from Apex. If anyone has any suggestions I’d appreciate the advice.

Here are some of the pics I sent Apex. Hoping they might illicit some advice from here.

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So I got my hands on a trigger pull scale and it lead to some interesting results. Unfortunately this scale maxes out at 8lbs buy it still proved to be helpful. Aside from the 327 PC I also own a 327 TRR8 which provided an excellent benchmark for comparison. Here is what I found.

327 TRR8 - Completely Stock: DA = >8lbs , SA = 4.5lbs

327 PC - Apex Evolution Hammer and Duty/Carry Rebound Spring: DA = 6.5lbs , SA = 4.5lbs

I was very surprised to see how light the DA pull was on the 327PC! It felt much lighter of course but I didn't expect such a substantial change as the main spring was left stock. This was obviously much too light for reliable ignition.

First Attempt:
In hopes of fitting a longer strain screw I ordered 2 different replacement N frame strain screws from Midway and Brownels's but unfortunately neither would work. Both of these screws were actually shorter than the stock screw. I'm sure there is reason for this but I do not know why at this time.

Second Attempt:
I ordered a Wolff Type 1 Mainspring which also came with 3 varying weight rebound springs. Comparing this mainspring to the stock mainspring I could easily notice it was much flatter. I assume this 327 came from the factory with the Type 2. I installed the new mainspring with the 13lb rebound spring.

Here are the results.

327 PC - Apex Evolution Hammer, Wolff Type 1 Main Spring, Wolff 13lb Rebound Spring: DA = >8lbs , SA = 4.5lbs

I used the stock strain screw and ensured it was fully seated with a small dab of locktite. The trigger now feels a tad heavier than the TRR8 but the force of the hammer is substantially greater and the pull is very short and smooth. The 13lb rebound spring must also be stronger then the Apex supplied spring as the trigger reset feels much improved.

Took it back to the range today and to no surprise I experienced 0 light primer strikes. I tried about 5 different types of ammo and alternated between using moon clips and not. Went bang every time. I need to put more ammo through it of course, especially the type I intend to carry, however I this time I feel I can consider this issue Resolved.

Afterthoughts:
This was my first time opening up a S&W revolver and I feel it was a great learning experience. I have much more respect for the 'harmony' that must exist between the internal components. I also better understand the reliability issues than can arise with a light trigger pull on a carry gun. My 327 now has a snag free hammer, a smooth but deliberate trigger pull, and reliable ignition. A happy ending indeed.

I think you did a great job, Octagun. Kudos for not giving up! There are a couple of things you can do differently to make all this easier, if there is a next time.

1 - You can replace the strain screw with a #8-32 socket set screw to make the strain screw adjustable. Use a 3/8" length for round butt frame and 1/2" length for square butt frame. Use blue Loctite 242 to coat the threads of the hole and setscrew, screw it in the hole and wipe off the excess. When the Loctite dries, you can adjust it with the allen (hex) wrench and it will stay where you put it. You can also make a small access hole in the grip so you don't have to take the grip off every time you want to fine tune it.

2 - You can use the trigger pull gage to weigh just the hammer tension by hooking it on the hammer instead of the trigger. This way you can measure the hammer fall without the trigger and rebound spring in the mix by holding the trigger back. You can start the hammer off too light, shoot some, adjust the strain screw 1/8 turn at a time, repeat, until you are at 100%. Then give the strain screw another 1/8 turn to catch that 1 in 100 potential misfires. Record the hammer tension for that gun so if you have to work on it later, you can easily return it to the same setting. If you want a strain screw with a head, you can find the hammer tension with the set screw, then alter a regular screw to give the same hammer tension with the head firmly seated.

After you have the hammer set, find the rebound spring that works the trigger way you want it to. Some like a minimum rebound for a lighter DA, some like a snappy rebound. You get to choose. You can weigh the rebound springs like the hammer spring by having only the rebound and trigger in, with the hammer out. All the different rebound springs are between 2 and 4 pounds of trigger pull.

I hope you or someone else finds this helpful.

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Thank you for your insight. Very helpful information.