I did a search here, but didn't find anything that directly addressed the information I'm seeking. So, here's my question.

What is the "lightest" DA trigger pull weight that can reasonably be achieved and still reliably ignite Federal primers? And, how is this achieved?

I've read the Kuhnhausen manuals and worked on a couple of my Smith revolvers (Model 19 & 686) to try to achieve a "great" DA trigger. I think I've achieved some success, i.e. pull weights reduced from 10+ (off my trigger gauge scale) to 6 1/4 - 6 1/2# and very smooth. However, I have read on other forums of Smith DA triggers in the 2-4# range. I would like to achieve this. Can anyone tell me what else needs to be done, beyond what is described in the Kuhnhausen manual, and replacement of the hammer & trigger rebound springs? I should add that these revolvers are not self-defense weapons, they are my NRA Action Pistol competition revolvers (primary & back up).

I would think that a 6# DA pull would be the best one could get without getting into reliability concerns. Doesn't NRA action pistol have a minimum pull weight as on autos?

I run mine at 6 lbs to keep some consistency with my heavier 617. Same rebound spring my 617 has puts my 625/627's at ~4 1/2 lbs. Radically lightened hammers are necessary. Shortened firing pin spring (on FMFP guns). Rebound springs get replaced. Some replace main springs some bend/recontour the stock spring. I modify Wolff reduced power main springs. Definitely requires some relearning with really light DA pulls. That's why mine stay 6ish+ lbs.

Randy Lee Apex Tactical Specialties has them running reliabley under 3 lbs.

More good info on this type thing can be found here: Brian Enos's Forums... Maku mozo! -> Revolver Forum

I'm not aware of any rule concerning trigger pull weights for revolvers.

Thanks for the links to Apextactical and Brian's forum. I browse Brian's forum but have not checked out the revolver section. Will do. Thanks.

+1 for Randy Lee at Apex tactical. I installed one of his L frame hammers this year and have the DA pull at 3.75. This is not for the meek to try to install. It did take a lot of tuning those little bits to get her there. I modified the stock main spring as see in the photo and a lightened an 11lb rebound spring. This is something I have not done to the spring in the past and its holding up well with little to no stack. Use With Federals Only. The other primmer out there will laugh at you if you try them. @ 4lb DA I had no issues with ignition. When I go under this to 3.75 I did have a miss fire during my last match, but I can not rule out the brass or primmer set correctly... Lighter than this my require a TI cylinder? Got me where they find the rest... but I have a few guesses.


Best
-Robert

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I did a lot of work on duty weapons back in the 70's - when EVERYBODY (almost) carried revolvers. The "Standard" for K-frame Smiths was to adjust the mainspring tension (using the tension screw)so that hammer lift (Trigger held in Pulled position, spring gauge lifting lowered hammer, hook of spring gauge engaging hammer just below firing pin) would be in the 3-1/2 to 3-3/4 pound range. Reliable ignition, improved DA trigger. But that is only part of a competent and complete revolver trigger job .... With certain other careful techniques, most revolvers came out of my shop with a trigger pull of 8 - 9 pounds. But more important than weight of pull is that the entire stroke of the DA trigger was smooth and uniform.

TRIGTECHR

You can definately overdo a light DA pull. Remember that the weapon still has to do a lot of mechanical things to get ready for the next shot and reducing the spring tension too much reduces reliabililty and the speed with which you can get off the next shot. Smoothness and consistancy of the action is more important than the exact weight.

BTW, 2-4 lb triggers are a whole lot easier to do on a keyboard than in the shop.

The only minimum revolver pull weights I've ever seen in the rule books (been a few years) were for single action. Which is why most PPC revolvers are/were DA only, there was no way they could meet the SA requirement.

Agreed. I've run mine low 4's but what it did mostly was screw up my timing. It would definitely take some relearning which is pointless since my 617 won't go near that light and I shoot both.

My revolvers still have the SA sears (the 617 has a spur too) but I hadn't paid attention to the SA pull weights, they get shot DA.
617-1 is 7 1/2 lb DA (set up to fire cheapo bulk ammo) and 1 3/4 lb SA.
627-5 is 6 lb DA, 2 1/2 lb SA.
Checked with a Lyman electronic gauge. The 627 won't quite lift the NRA 2 1/2 lb test weight.