Ultra Light Trigger Pulls

[Randy Lee]

Hello all,

I thought I'd start a new topic on light trigger pulls. I thought I'd share what I've learned and what input some of the others who are running my guns are putting forth.

Anyone using my trigger work or hammers, please chime in- good or bad. The only way I can learn and improve what I make and do is thru data I get from you the shooters.

I started my quest for the Holy Grail because people said a trigger pull under 5 lbs couldn't be done and maintain reliability. After that barrier was broken, I wanted to know how light could I go. At present, 2lbs. 14 oz is the new barrier- and I'm happy with that.

Using the .357 flavor of the 627 8 shot revolver as a common point of reference and Steel Challenge shooting as the venue for this discussion, I've found that the light trigger pull weight(3.5-4.5lbs.) with it's lighter trigger rebound does not adversely affect speed. Vic Pickett has been able to run .15-.16 splits with a 3.5 lb trigger.

Input I've received from Jason Pettitt is that shooting his Steel gun with a 4 lb. 3oz. trigger is posting faster times with his 627 from the draw than with his .22 revolver from the ready position on Smoke and Hope. Jason explained to me that the last several years, his emphasis was/is to get his revolver moving as fast as he can and chase the trigger to make sure the hammer fell when his sights were on the plate. He also had to work his trigger finger harder to time the hammer fall with the sight picture. With the lighter trigger pull, the revolver cycles faster from the beginning of the trigger stroke to the point of hammerfall. What he discovered was that now the gun is capable of going "Bang" before his transition to the next plate is complete. In essence, it is his physical ability to move from target to target which is the limitation and not the gun or it's trigger reset. Once he adjusts to the faster timing, I suspect his times will drop further.

The feedback that Jason and Vic give me is invaluable. They can operate the guns as fast if not faster than before but don't have to fight through the resistance of a heavy trigger stroke. While true that the trigger return is considerably lighter than the norm, it doesn't seem to adversely affect split times once accustomed to it. It does require you to actively move your finger to the reset rather than rely on the rebound spring to do the work for you. It just takes getting used to . If you practice the trigger slap as Todd Jarrett does, the light trigger pull will allow you to operate the gun faster than you might expect.

Another advantage of the light trigger pull is that you can use the tip of your finger pad to operate the trigger- especially if you use the narrow serrated trigger. Jerry M. has mentioned this upon several occasions. Fingertip control of the trigger allows you to finesse the trigger stroke and only use the minimum physical effort to cycle the gun without affecting the sight alignment. On most of the revolvers that I have been working on as of late, 95% have requested the serrated triggers be installed- it simply allows you to engage the trigger surface with the most sensitive part of your finger without slipping past. Prior to the sub 5lb. pull, the serrated triggers were not favored because of the number of blisters they caused. At 4.5 lbs, the serrated surface has a positive affect on how you interact with the gun. It's not for everyone, but for me it works.

Now for the bad part. Because you can stroke through the trigger pull faster, the amount of torque you will experience as the cylinder comes to a jarring halt will be more pronounced. This becomes very pronounced in heavy unfluted cylinders with heavy bullets. There is more stress on the cylinder hand, timing ratchets on the extractor star, the cylinder stop and on the impact surface of the cylinder stop notches . The increased stresses on these parts are the reasoning behind the Titanium cylinder- at least in part. The metal on the timing ratchets is relatively soft. Furthermore, as you increase the number of charge holes in the cylinder, the smaller the ratchets become, as does the engagement surface on the hand. Timing will tend to go out faster on 7 and 8 shot guns when compared to their 6 shot counterparts. I've also seen more hands break on 8 shots than any other variant. We're concentrating a lot of force on the smaller (almost half width) tip of the hand. The faster we are capable of pulling the trigger- i.e. rotate the cylinder, the more stress, wear and tear we impart. Fortunately the new CNC produced extractor stars are available from Smith and can be fitted to existing guns.

Traditionally, 2.0 lbs of hammer fall force is required to ignite a Federal 100 small pistol primer. With a lightened hammer you can shave off up to 6 oz. off that number. The lighter I go with the trigger pull weight, the more I must pay attention to primer seating practices at the loading bench. With the sub 3 lb trigger gun, primers must be seated to max. depth without deformation of the primer cup.

Please note- it is possible to seat the primer so deep that there is no space between the primer anvil and the cup. There must be enough distance between the anvil and the primer cup so that the incoming firing pin can crush the priming mixture between the deformation pocket that the impact makes in the primer cup and the anvil. I have seen instances of this recently and it takes over an additional pound of hammer fall force to ignite- and this was measured on a lightened hammer. If you cannot get your revolver to reliably ignite a Federal primer at less than 6lbs, primer seating may be an issue.

When seating primers on my Dillon 650(38spl) I will seat the primer firmly once, then rotate the case about 180 degrees and press once again on the handle. If you look at the case as you seat the primer, you will notice that the act of seating the primer causes the entire case to rock towards the center of the shellplate. This is due to a couple of factors- clearance so the shellplate can rotate freely, clearance in the shell plate for the case rim and the open space so the case can slide into the shellplate. All three factors will allow the case to cam slightly as the primer is seated. What this means is that one side of the primer is not being fully seated against the interior wall of the primer pocket. Rotating the case and reseating ensures that the opposing side of the primer is fully seated. If you look at my primers they are seated deeply, but not deformed. I perform this operation on my match ammo primarily because I found that with lighter hammers and pull weights, the primer will be the first thing to shift if not fully seated. If my firing pin just happens to hit on the unseated side of a single press seated primer, it may have enough movement to dissipate the force necessary to ignite the mixture.

I have done this for my 38 spl rounds and have not had a misfire with the sub-3 lb pull 627.

The light trigger pull has many merits, but again, may not be necessary for everyone. It requires the user to retrain how they interact with the gun, it is obviously not cheap, and it requires one to pay close attention to reloading practices that they might not otherwise consider.

Hope this all makes sense and is helpful information to those considering trigger work from anyone, not just me.

Randy

[spook]

Great post Randy! Thanks!

[Trader]

Have the titanium cylinder guns had any problems related to the titanium itself?

[R112mercer]

My 625 has an action job by Randy on it. I've never had any problems with trigger return speed, but then I tend to have really slow splits (.20 range). I've always used the center of the pad of my finger when shooting, and the lightened trigger makes this a lot easier.

Incidentally, here's an old trick I was taught. If you're looking to find the "stop" on your trigger (the point in double action where the hammer stops right on the sear and needs just a tad more pressure to drop the hammer) reach your trigger finger all the way in. When you pull the trigger the tip of your finger will touch the back of the trigger guard right before the sweet spot. It's tough to do when you want to go fast, but if you're looking for a little extra accuracy give it a try.

As to primers, Randy said my handloads had some high primers in the mix, so I bought a decapping die set-up for my 650 and decap my brass, then use a primer pocket uniformer on them. It's a real PITA, but you only has to do it once to make sure the pocket in square and deep. I found with the brass I'm using (Federal brass off the range floor) that some of those pockets need a lot of cutting to get squared up. There's also a lot of primer crud in some of those pockets, the uniformer gets rid of that, too. My gun has been through an Area match and the Nationals without a single light hit.

[JohnRodriguez]

hey Randy

How about coming out with a trigger the way you did with your lightened hammer. The factory ones are kind of sloppy and your basically stuck with what you got from smith, no way to really adjust the timing. For me these would be for my PC guns and 625 with a forged trigger installed in it. Yesterday, while dry firing my 625, the cylinder stop was engaging to soon and locking up. I ended up having to take a dremal to a spare stop and elongating the hole (towards the front) to get more engagement on the trigger sear. The gun seems to run fine now, but wont know untill this evenings practice.

About the only way to improve you hammers for me, wouldd be to cut the single action step. This would make getting rid of the light hits that you accumulate over the coarse of the day.

[Randy Lee]

As soon as I get the new 325 cylinder from Smith I'll be able to do more a more thorough analysis. The Titanium is ususally alloyed in with Vanadium and Aluminum to make it machineable. It has great tensile strength, but in it's raw form is not very resistant to abrasive wear. Smith treats the surface to resist wear and from what I've experienced, the cylinder holds up very well.

Carmoney points out that the 646 has had problems with extraction. I plan to talk to the engineers at Smith once I have a chance to work with the existing 325 cylinder. They may have already addressed the sticky extraction issue.

Thanks Spook! Best of luck at the World Shoot.

A new trigger is another project. It's a bit more complex in design so it will take me more time to figure out what I want in geometry and function.

Randy

[cooper_999]

whow, never read such a detailled report on trigger issues....thanks for a lot of new ideas to deal with....

DVC!

Sascha

Spook are you still in Ned or already in Equador? Good luck there!

[spook]

Leavin' for the airport in 5 minutes! See you guys after the World Shoot!

[cooper_999]

Leavin' for the airport in 5 minutes! See you guys after the World Shoot!

<{POST_SNAPBACK}>

have a nice trip!

DVC!

Sascha

[dillon]

Randy,

If you are getting uneven primer seating on your 650, try tightening the shellplate bolt just a smidgen. If you push down on the edge of the shellplate between stations 3 and 4, it should not feel springy. How many times has your brass been fired? Another well known ICORE shooter contacted us with a problem loading on his 650 which we couldn't duplicate. turns out that his cases had been reloaded 20+times. Once he acquired some new brass, everything worked as intended. I am as big of a brass whore as anyone, but I buy new brass every year for the IRC, then use it for monthly and practice matches the rest of the year. over time, even 38s will deform.

Finally, for your volume, you might consider going up to a Super 1050. It seats primers on the downstroke, and primer seating depth is mechanically adjustable, not by how hard you push on the handle. It isn't inexpensive, but like your action jobs, it will spoil you!

[Randy Lee]

Hi Dillon,

There is about .005 " clearance between the shellplate and the base of the ram.

At the 4.5 lb trigger pull range, rotating and reseating isn't really necessary. Rotating the brass does allow me to compensate for a non uniform primer pocket as well as an irregularly shaped primer cup. Some of my practice brass is pretty old, but for the big matches, I agree, new brass is the way to go.

I do have a Super 1050 set up for 38 supercomp perhaps it is time to switch it over to 38 spl. . Or, if I have any money left over after paying Dave Hearth for the next batch of hammers, the business can purchase one.

Thanks for your help,

Randy

[bountyhunter]

Have the titanium cylinder guns had any problems related to the titanium itself?

<{POST_SNAPBACK}>

Yes. The temp coefficient of expansion is different and it is possible to get binding when the cylinder gets very hot.

[Airedale]

I've never met Randy Lee nor do I portray him on TV

But I have a 25-2 that I'm doing a trigger job on. It refuses to fire consistently below ~8lbs. DA. I have worked at it until I was ready to trash it or sell it to that "new shooter" Carmoney.

I called Randy looking for advice. He stopped what he was doing and talked me through basically what is in the post above and some other things. He probably doesn't have the time to waste on home gunsmiths but did and I think that's great.

Thanks for your help Randy and once I gunsmith this 25 to the point it won't fire anymore (at least another week), I'll box it up and have you make it right.

You are a class act-thanks.

Dave

[Randy Lee]

Interestingly enough, the thermal expansion of the Ti cylinder is less than the steel counterpart. The particular 627 test gun has been running a .004 B/C gap without binding.

IRC gun(also with Ti cylinder) was running a .003 gap and the loads I ran with the Sierra 170 gr. bullet were 8 power factor points higher than previous years with .3 gr. LESS powder.

Go figure...

Randy

[Randy Lee]

Thanks Dave!

Seems like most people I've met on this forum are great people. Revolver shooters just seem like nicer people all the way around!

[Round_Gun_Shooter]

I usually stay out ot Technical discussion because I am just a dumb revolver shooter.

The Ti 646s IIRC had and have their problems due to the pressure of the load. I shoot my Ti 38spl carry gun and have no problem. I had a 325PD until the IDPA PF changes as it was going to become my IDPA SSR gun.

After the rule changes, I tried the 325PD with some 170PF loads and some hot factory loads. (CORBON) The gun was a little uncomfortable to shoot extensively with these loads but I had no problem with function or extraction. Everything acted as it should.

I think the Ti cylinder on the 45ACP revolver is a great idea and I look forward to test reports.

Best to you all, I am off to the NE IDPA regionals in NH (outlaw unsanctioned match under old rules this year ). Mike might remember Pioneer R&G in Dunbarton. Great bunch.

Going to give my 66-1 a workout in SSR.

Regards,

Gary

[JD45]

"....and primer seating depth is mechanically adjustable, not by how hard you push on the handle."

Well, you just made the decision for my next press real easy. It's 1050 all the way now.

[pmd]

but then I tend to have really slow splits (.20 range).

<{POST_SNAPBACK}>

.20 splits - I wouldn't call that "really slow" - I wish I could produce that speed and hit my target..

[Randy Lee]

I forgot to add a bit about moonclips and chamfer jobs on cylinders.

I have found that bent fins on the moonclip can lift the case head off the cylinder seat and absorb enough force to contribute to misfires. I will usually check my match loaded moonclips in the cylinder and check for springing on each round in the cylinder.

Recently several guns have been sent to me with what I would consider excessive chamfering of the charge holes. On the .357 cylinders, headspacing should be referenced off of the surface of the cylinder. on 627s and 686s there should be enough metal left to support the case rim. You should be able to shoot rounds with or without moonclips. On one 627 which I'm working on now, the chamfer job forced the user to only use moonclips or risk blowing primers out of the cases. while he could and did use the gun, the headspacing increase which resulted from the over-chamfer job had another unforseen consequence. As the cartridge fired, the primer would shift rearward enough to let gases escape between the primer pocket sidewall and the primer cup. The gases quickly eroded the firing pin bushing and replacement was necessary.

On a recent 625, the chamfer job was executed while the extractor star was still in place. The chamfer cutter cut into the timing ratchets enough to impair timing of the cylinder and affect the quality of the trigger work. A new extractor assembly and fitting costs were incurred.

Over chamfering on .357 revolvers can force the gun to rely on the thickness of the moonclip for headspacing and as in the story above cause damage to the gun. In terms of proper headspacing, the cartridge may rest too far forward and cause the firing pin to decelerate as the firing pin return spring begins to compress. The affect on the trigger pull is that hammer fall weight must be heavier to compensate for the distance. This can be why some guns won't be 100% reliable at 5,6 and sometimes even 7 lbs.

These are some of the other things I've had to consider as I worked on lightening trigger pulls.

Just some additional stuff to consider.

Randy

[Shoepop]

Randy, I found your post on primer seating depth interesting but it left me a little confused which is very easy to do! I have two revolvers you worked your magic on. My 625 DA pull is 4.4#'s. I load on 1050's and adjust my primer station's to seat the primer 'Federal' with no 'dome', they are essentially flat. I have never had a misfire out of the 625 or the 627/38 super which break's @ 4.5#'s. Question, can one reduce pull even further if the primer is seated fully but leaving the primer 'cup' shaped in lieu of flat ? The 100 test loads I sent you for each revolver all had flat primers which I'm sure you used to make sure of reliable ignition. One last thing. Can I send you my 627 V8 anytime soon

[Randy Lee]

Shoepop,

I believe the answer is yes. I typically run triggers at 4.0 lbs with my test ammo but increase mainspring force by 8 oz. as a fudge factor for reloading and moonclip variances. You should be able to drop 2-4 oz. off the pull weight by adjusting the seating depth.

I think I need more safes

[michaels]

Dr. Lee,

does having an extended firing pin play into the trigger pull weight?

p.s. - that other gun is coming to you on Monday or Tuesday next week....

mike sousa

[Airedale]

Randy,

The chamfering post is great information. The 25-2 I discussed with you came from an old time LEO. It is the most "heavily" chamfered gun I've ever seen. I can drop moon clips from "great heights" and reload this one. This may explain some of the misfires.

I may take a pic of the cylinder and email it to you.

Dave

[AzShooter]

I've had Randy do two trigger jobs for me. One was the perfect example of a cylinder that has been chamfered too much and he was about to work reliably at about 4.5 lbs. I love this gun and the trigger pull on it. Very smooth and it will reset every time with no problems. I have never had a failure to fire with this gun. I do all my loading on a 650 and as long as the primers aren't too high to even rotate in the cylinder they will go off.

My second gun is just at 4 lb or a little under. Again, I have had no failure to fires with either gun but this one has given me a little problem with resetting the trigger. It's my timing, not Randy's work. Just remembering to get the trigger finger completely off the trigger after each shot has eliminated the problem. But I'm still practicing to do it all the time.

What I like most is that with these super light triggers I can take advantage of concentrating on the trigger and the sight. When I miss I now know exactly why. I can feel the gun track to the target. I can feel the sights in line all the way through until the gun fires.

[AzShooter]