How light can you go with double action trigger

[JAB]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

[314shane]

Oh boy!! Here we go. There's a ton of factors in the question your asking. First off I'm not the best one to answer your question and the exact answers are going to vary from gun to gun. Secondly what are you wanting to use for primers.

[PatJones]

Apex is doing some very light triggers in the 3-4 pound range I believe. I find it too easy to skip by a chamber with a trigger that light and I set mine to just over 6 lbs double action.

Keep in mind light triggers in a revolver -require- hand loaded federal primers.

[PatJones]

The main benefit of a bobbed hammer as I see it is added safety. When set to 6 lbs double action, the single action is so light it's really not safe. A bobbed hammer removes the single action function.

Edited February 21, 2016 by PatJones

[AzShooter]

If you want it done by a competent gunsmith, ApexTactical is the way to go. Randy Lee can get it down to 4 lbs with no problems.

For do it your self getting it to 6 lbs takes a lot. You can radically trim the hammer, replace the rebound spring with an 11 lb spring and replace the main spring with a lighter one. You can also order a hammer from Apex which will let you get to the 6 lb goal.

The problem is that many people go too light and get misfires. My Apex gun has had thousands of rounds through it without a problem.

I understand that TKCustom does a great trigger as well.

The main problem is getting off the trigger after the shot. Otherwise you will skip a chamber. You need to balance the springs probably by loosening the strain screw. I use a Black Magic spring kit from Vic Pickett to get my 929 down to 5 1/2 lbs reliably. If I go any lighter I get misfires.

Bobbing the hammer lets you get your hand very high on the gun without getting bit by the hammer during your pull. The other benefit is with a light hammer it falls faster and therefore sets off primers better. You really need to watch how you seat the primers. Get them below flush and you can insure ignition.

[Carmoney]

To get to Apex Tactical's website, simply Google the word "Carmonize." Apex's site will be the first one that appears!

[alecmc]

Somewhere in the neighborhood of 5-6 lbs is standard, you could get down into the 4.0-4.5 lb range, but this severely slows down the trigger rebound spring/speed.

A bobbed hammer is lighter, which travels faster. E=mc2 and stuff, and it gives better ignition at lighter main spring weights.

All of the above is only possible using FEDERAL PRIMERS properly seated (fully seated at 0.08-0.10 below flush)

[alecmc]

To get to Apex Tactical's website, simply Google the word "Carmonize." Apex's site will be the first one that appears!

Had to try it, pretty funny

[okshootist]

Unless you know and can replicate the method of measuring the trigger pull, the number is useless.

[Toolguy]

All of the above is only possible using FEDERAL PRIMERS properly seated (fully seated at 0.08-0.10 below flush)

I think you meant that to be .008 - .010.

[pskys2]

Just remember the lighter you go the the touchier it gets. You can get a sub 4 lb action job, but if you have a marginal moon clip it might not fire, if your head space or end play loosens up you will have misfires, If you have a primer pocket with excess carbon build up you can have a misfire.

A sub 5 lb action also will have very light rebound pressure, which can cause you to short stroke an action and skipping chambers.

One reason why the 6 lb action job is so popular. It is pretty easy for us average joes, gives positive rebounding, gives you a cushion against the minor issues of moon clips, etc.. and will last through many thousands of rounds.

Of course if you get a 4 lb action you can play with that, change the springs (so you don't lose all that effort it took to get it) to a 6 lb action. After playing with both you can then make your own decision on what you need to maximize your skills.

[alecmc]

All of the above is only possible using FEDERAL PRIMERS properly seated (fully seated at 0.08-0.10 below flush)

I think you meant that to be .008 - .010.

Correct

[FWSixgunner]

Az is correct: a bobbed hammer allows a higher grip. I go way high with my stubby fingers.

Recoil control improved as your hand gets closer to the bore.

Sent from my iPhone using Tapatalk

[bountyhunter]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

DA pull min depends on how much you want to "restrict" things like only using soft primers, competition only (not for defense/duty service) etc.

I can get DA down to about 7 - 8# and probably ignite 98% of the ammo that exists...

[bountyhunter]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

One benefit is it typically will improve strike energy a little by reducing hammer mass. Not a lot, but a little. It seems backwards but all "competition" hammers and strikers reduce mass to get faster hammer velocity and increase strike energy.

[MrBorland]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

One benefit is it typically will improve strike energy a little by reducing hammer mass. Not a lot, but a little. It seems backwards but all "competition" hammers and strikers reduce mass to get faster hammer velocity and increase strike energy.

Just to clarify - in and of itself, bobbing the hammer doesn't change strike energy. The mainspring provides the energy - the hammer merely transfers it. Bobbing the hammer increases hammer speed, so it increases strike power. Energy itself (nor momentum) doesn't light off primers - power lights off primers, since power is good at denting things, like the primer. Think of a baseball bat or claw hammer in full swing meeting your car's bumper - not a lot of momentum, but lots of power, and dang if it won't put a nice dent in your bumper.

Another small benefit to reducing hammer mass is that momentum is reduced. As mentioned, momentum does nothing towards lighting off primers, but momentum will jar the muzzle upon hammer strike. A lighter hammer, then, allows one to tune their gun's action lighter before ignition reliability becomes an issue, but it can also result in a small increase in the gun's inherent accuracy. The effect of a light ("Carmonized") hammer on muzzle jar can be seen in the video below.

[toothguy]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

I wouldn't try to hard to get an actual trigger pull number. First get the action smooth with a low resistance rebound. The hammer spring needs to be about 38-40 oz., or what ever it needs to be to set off the type of primers you have. The other variable is the rebound spring. I usually start with an 11# an cut 1 or so coils off. The rebound spring weight and the resistance of the top of the rebound slide are really important so you don't bind up the trigger when it doesn't fully return. What ever the trigger pull is at that point is what it needs to be.

If I remember right at one time you were interested in shooting Action Pistol. You need good rebound at the 10 yrd barricade because you're ripping the shots off pretty fast and with a weak rebound it's easy to clutch the trigger. For Action Pistol it probably will end up being about 6.5 lbs or so. I would run it a little heavy for reliability and also, if you can, use a 7 round cylinder.

[JAB]

yes im still interested in shooting action pistol but up here in Canada there not a lot of it. Im shooting ipsc and icore right now, ill be sending it out next month to the gunsmith to be cut for moonclips so while there im thinking I might well get a few things done to it

[bountyhunter]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

One benefit is it typically will improve strike energy a little by reducing hammer mass. Not a lot, but a little. It seems backwards but all "competition" hammers and strikers reduce mass to get faster hammer velocity and increase strike energy.

Just to clarify - in and of itself, bobbing the hammer doesn't change strike energy. The mainspring provides the energy - the hammer merely transfers it. Bobbing the hammer increases hammer speed, so it increases strike power.

Nope, I said it as I meant it. It does indeed transfer energy from the mainspring, but the hammer's energy is given by:

e = 1/2 Mass (velocity) squared

The energy goes up with the square of velocity so that's why reduced mass strikers that fly faster increase energy. Most guns hammers and strikers have a size/mass much larger than "optimum" for the tradeoff of velocity and mass, hence you see increased energy hammers and strikers are always smaller/lighter to get increased strike energy at the firing pin.

It is no coincidence that getting the DA pull on a SW revo to maybe 3# requires reducing the hammer mass to bare minimum (see apex hammer).

https://store.apextactical.com/WebDirect/Products/Details/191687

Edited February 23, 2016 by bountyhunter

[bountyhunter]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

One benefit is it typically will improve strike energy a little by reducing hammer mass. Not a lot, but a little. It seems backwards but all "competition" hammers and strikers reduce mass to get faster hammer velocity and increase strike energy.

Just to clarify - in and of itself, bobbing the hammer doesn't change strike energy. The mainspring provides the energy - the hammer merely transfers it. Bobbing the hammer increases hammer speed, so it increases strike power. Energy itself (nor momentum) doesn't light off primers - power lights off primers, since power is good at denting things, like the primer. Think of a baseball bat or claw hammer in full swing meeting your car's bumper - not a lot of momentum, but lots of power, and dang if it won't put a nice dent in your bumper.

linear momentum is given by:

p = mass x velocity

A claw hammer at full swing actually does have some serious momentum, but the reason it is so good at denting is the strike energy is localized on a small surface area when it hits. Same with a bat (assuming its a metal bat and it doesn't collapse under impact).

Bottom line, people who maximize ignition energy to allow comp shooters to minimize mainspring force reduce striker/hammer mass. So it's energy they are maximizing, not momentum.

Anyway, my original statement was correct: removing some mass from the hammer DOES increase strike energy, NOT mainspring energy, but it delivers more energy to the strike. The farther the mass is away from the pivot, the more effect so clipping the spur will have some effect.

Edited February 23, 2016 by bountyhunter

[MrBorland]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

One benefit is it typically will improve strike energy a little by reducing hammer mass. Not a lot, but a little. It seems backwards but all "competition" hammers and strikers reduce mass to get faster hammer velocity and increase strike energy.

Just to clarify - in and of itself, bobbing the hammer doesn't change strike energy. The mainspring provides the energy - the hammer merely transfers it. Bobbing the hammer increases hammer speed, so it increases strike power.

Nope, I said it as I meant it. It does indeed transfer energy from the mainspring, but the hammer's energy is given by:

e = 1/2 Mass (velocity) squared

That equation is the source of much confusion on the matter. That equation merely indicates how much energy the hammer transfers - it doesn't indicate in any way the hammer's the source of the energy. The spring is the source of the energy, and one can use equations that use the spring constant to come up with the same number (or the potential energy of the compressed spring).

If the springs remain the same, heavy and light hammers transfer the same kinetic energy. A lighter hammer just delivers that energy faster, which is to say with more power. Conversely, a stock (i.e. heavy) hammer pushed by a very light mainspring is slow, and loses a lot of power; and since it's power that dents primers, you gotta bob the hammer when you want a light and reliable DA pull.

[PatJones]

I fail to see how a lighter hammer helps ignition of a centerfire cartridge, yet a heavier hammer helps the ignition of a rimfire cartridge. My unmodified hammers reliably pop primers with the triggers set to less than 6 pounds.

As a gunsmith I have concerns about how light the single action is on a revolver tuned for a light double action pull. I don't consider a 1 pound single action trigger safe for the typical customer. Deleting the single action function resolves this concern.

Bobbed hammers are certainly "racier" than a stock hammer; a bobbed hammer screams "race gun". I just haven't seen any measurable benefits to ignition at typical USPSA trigger pull weights.

[bountyhunter]

I fail to see how a lighter hammer helps ignition of a centerfire cartridge

But everybody who makes aftermarket hammers and strikers do everything they can to eliminate as much weight as possible from the hammer. Look at the Apex hammer for SW revos. Look at the Lightning Strike strikers for Glocks. On my Glock 35, I was getting about 50% light strike misfires with a very light competition striker spring that came in the aftermarket kit to give a 2.5# trigger pull. I could have gone to a heavier striker spring, but instead I dropped in a reduced mass striker and the misfires were eliminated instantly with NO OTHER CHANGE. The point is, reducing hammer mass (or striker mass) does give better strike efficiency. The reason is that there is an optimum mass for getting best transfer of spring energy to the strike, and hammers and strikers are always heavier than that simply because of the physical size of the stock piece. So reducing mass gives a hotter strike. There obviously would be a point where reducing mass further made it worse, but I suspect the part could not be made that small.

There is a ton of info posted on this site about grinding down hammers and strikers to reduce mass. Here is one from somebody here showing how to dremel a stock striker to make it like the Lightning Strike type. Reduce as much mass as possible.

Edited February 23, 2016 by bountyhunter

[bountyhunter]

Bobbed hammers are certainly "racier" than a stock hammer; a bobbed hammer screams "race gun". I just haven't seen any measurable benefits to ignition at typical USPSA trigger pull weights.

I haven't yet tried an apex hammer (because of cost) but I have seen posts claiming it's possible to get DA pulls under 3# using them. That is impossible with a stock heavier hammer. Some of the pros can chime in, but that is the whole point of the thing: can still fire the primer with a SUPER light mainspring.

Some people run a skeletonized or bobbed hammer for looks, but they also do have a functional aspect.

Edited February 23, 2016 by bountyhunter

[bountyhunter]

what the lightest lbs you can get a 686 double action trigger down to, and how did you do it. Plus what benefits is there to bobbing the hammer.

One benefit is it typically will improve strike energy a little by reducing hammer mass. Not a lot, but a little. It seems backwards but all "competition" hammers and strikers reduce mass to get faster hammer velocity and increase strike energy.

Just to clarify - in and of itself, bobbing the hammer doesn't change strike energy. The mainspring provides the energy - the hammer merely transfers it. Bobbing the hammer increases hammer speed, so it increases strike power.

Nope, I said it as I meant it. It does indeed transfer energy from the mainspring, but the hammer's energy is given by:

e = 1/2 Mass (velocity) squared

That equation is the source of much confusion on the matter. That equation merely indicates how much energy the hammer transfers - it doesn't indicate in any way the hammer's the source of the energy. The spring is the source of the energy, and one can use equations that use the spring constant to come up with the same number (or the potential energy of the compressed spring).

If the springs remain the same, heavy and light hammers transfer the same kinetic energy. A lighter hammer just delivers that energy faster, which is to say with more power. Conversely, a stock (i.e. heavy) hammer pushed by a very light mainspring is slow, and loses a lot of power; and since it's power that dents primers, you gotta bob the hammer when you want a light and reliable DA pull.

Well, it's been a few decades since I did dynamics problems but I recall that when the mass is rotating on a pivot, the effect was proportional to the radius squared from the pivot point. Which is why even a small mass change out near the edge has a viable effect. And that's what I told the OP.

The thing I know with 100% certainty is that reducing mass on the hammer or striker, for a given spring weight, gives a hotter (more effective) strike. Seen it myself as posted about my Glock 35. It's why reduced mass strikers exist and why people pay $80 for them....

Edited February 23, 2016 by bountyhunter