Howa HACT Trigger adjustment

[Againstthegrains]

So I'm diving down the knowledge rabbit hole here.

I have 1 Howa rifle that the trigger was done by a gunsmith and the trigger is amazing, no idea what he did, but its safe, crisp and breaks with less weight than standard.

I am buying a second Howa rifle and would like to try doing the trigger myself, so here is the conundrum: there seems to be a lot of ways to create this effect on a Howa trigger, but as usual, I have no idea which of these work best, and which are the most cost effective.

I have found the following options, (there may be others?)

1. Dissemble the trigger, and cut 1.3-1.5 coils off the spring that connects to the actuator. Then reassemble. Can also polish the important surfaces a bit.

2. Buy a spring kit: there is an Aussie guy that sells kits with different drop in springs to give different pull weights. Don't know if you can get these locally, or maybe buy a bunch a springs from an engineering works to play with?

3. Buy a drop in replacement trigger from these guys at 360 Arms

Has anybody on the forum done any of these mods and have pro's and con's for each?

[223]

So I'm diving down the knowledge rabbit hole here.

I have 1 Howa rifle that the trigger was done by a gunsmith and the trigger is amazing, no idea what he did, but its safe, crisp and breaks with less weight than standard.

I am buying a second Howa rifle and would like to try doing the trigger myself, so here is the conundrum: there seems to be a lot of ways to create this effect on a Howa trigger, but as usual, I have no idea which of these work best, and which are the most cost effective.

I have found the following options, (there may be others?)

1. Dissemble the trigger, and cut 1.3-1.5 coils off the spring that connects to the actuator. Then reassemble. Can also polish the important surfaces a bit.

2. Buy a spring kit: there is an Aussie guy that sells kits with different drop in springs to give different pull weights. Don't know if you can get these locally, or maybe buy a bunch a springs from an engineering works to play with?

3. Buy a drop in replacement trigger from these guys at 360 Arms

Has anybody on the forum done any of these mods and have pro's and con's for each?

I have modified a few of these.  What I did was to grind off a bit of both spring springs.

There are 2 springs:
One that is the actual sear spring and other that works on the actuator (finger lever).
On the sear spring, turn the tension screw out and screw it in 3 or 4 turns.  Then shorten the spring until it will just fit in without any tension.  You can now use the adjustment screw to set it's tension as light or heavy as you like it.
On the actuator (finger lever), you can shorten the spring a little.  Don't cut too much off, as then the lever will not return forward when released.  If you manage to shorten it beyond that point, just stretch it out a little bit until it works again.

You can also change the trigger to a single stage by installing a small tube or bush around the roll pin that stops the actuator.  The thickness of this bush needs to be just right to take up all the "take up" movement.  Some people also drill out the hole and install a thicker roll pin.  This is not reversible if you over-do it, so be very careful.

To shorten the springs, I push them over a jewelers screw driver tip to keep them stiff and grind the spring shorter on a bench grinder.  Small cuts and don't destroy your screw driver.  Measure twice, cut once.

Don't loose the little circlips...

There are replacement trigger levers on the market that replace the 2-part system with a single trigger. They should come with detailed instructions.  The same precautions apply. 

When everything is adjusted and assembled, do a proper safety check.  I like to bounce the rifle on it's recoil pad (cocked, safety off) to see if the firing pin will fall.

[Treeman]

I have found modifying triggers to be a very satisfying activity. I have played with pen springs, carburetor springs and every other spring I saw. One of my rifles at this moment is using the stainless spring found in a boats fuel tank attachment, the black part that connects to the tank - has a ball that gets pushed back against a spring, that spring. The old Parker type click click pens, some have just the correct spring. I never just throw a spring away, have a bottle  for compress springs and one for tension springs. Same with tiny screw, nuts bolts, got a little container full.

If you know your way around a welder two stage triggers can be welded up and then ground to new profile. If you ever file on a trigger do remember to case harden finished product again. The triggers I have met all had a thin hardened casing that filed through.

Put trigger on scanner- photo stat and print out, use that to ponder it all.
I enjoy taking a flat plank and building the trigger on it using nails as pins and arbitrary springs I have to recreate the trigger action and ponder building up, grinding back.
When ever reducing or even polishing a trigger, always make sure you have a physical something to keep it all square - you will regret not doing this.
I do not like cutting or shortening springs, something about made to work lengths and all - besides, a higher poundage (safe) trigger with a short engagement, short release and sharp release is better in my eyes than a light trigger that imitates a good trigger. (for hunting that is)
The only trigger that was shit and stayed shit and did not get much better with much work has been the .303 Lee, that thing will age you. I even got a spare action to try beat that thing - with out a milling machine, tig and some fancy engineering degree that trigger will make you wish for vaseline.     

[Ds J]

Oom Louw van Deventer (vorige eienaar: Advanced Guntech Potchefstroom) het twee van my vuurwapens se snellers gedoen. Hy het hard en duidelik gesê dat n mens baie versigtig te werk moet gaan as jy aan die metaal wil skuur. Dit vat letterlik n enkele haal met n vyl om onherstelbare skade te maak. 

Sy raad was om met ekstra-fyn vyle en/of skuurpapier te werk, en deurlopend te kontroleer.

[Againstthegrains]

You can also change the trigger to a single stage by installing a small tube or bush around the roll pin that stops the actuator.  The thickness of this bush needs to be just right to take up all the "take up" movement.  Some people also drill out the hole and install a thicker roll pin.  This is not reversible if you over-do it, so be very careful.

Thanks, this is interesting. Do you know the exact diameter of the bushing/thicker pin that you need? and can you point out on the diagram exactly where it goes?https://highvelocityhuntingaustralia.com.au/wp-content/uploads/2018/08/HACT.png

I presume either position 2 or 9 will stop the travel of the 1 stage?

[oafpatroll]

I'm a keen tinkerer but beyond polishing, minor spring fettling and parts replacement I'm not up for trigger buggery. Some pretty small changes can have outsized effects. Something that has imprinted on me was a 1911 with a 10 round mag that went auto and almost out of control in the hands of an overconfident gun plumber.

The tolerances and precision required to get a top class job on something like sear to hammer engagement on a pistol are beyond my skills and the results I've achieved in case hardening have been iffy at best.

Had great results in upgrading my CZ75 with a raft of Cajun Gunworks parts and a lot of very careful polishing on trigger stirrups, hammer spring stirrup and other surfaces. Also got great results using a YoDave kit on a Brno rifle. Those are about where my confidence level runs out. 

 

[Againstthegrains]

I'm looking at 3 replacement triggers that I can find on the market locally::

This one from 360Arms Its a straight trigger that is an actuator and trigger in one, that goes in the same place as the actuator. It is not offset like the others, and seems like the trigger may be more forward than it was before. It apparently converts the trigger to a single stage. Costs R899

And this one from Fanatac looks a more like the others on the market. With integrated actuator and offset blade, so it goes in the same position of the original blade. No information if it works with the HACT trigger or the older Howa or both, and if it is a single stage? Its the cheapest at R755

This one from Sudami X looks like the previous one, but is more than 2x the price of the others.

Has anybody here any experience with them?

[janfred]

What is an actuator?

[jager]

IMHO just go for option 1. It will cost you R0, and it makes for an excellent crisp trigger. (although still 2 stage, but I like a 2 stage trigger) And it never hurts to know the insides of your gun and how things work.

You can pay almost 6k for a drop in Timney, and it won't be much (if any) better than just cutting 1.2 coils from your current trigger. I reckon that's money better spent on bullets, powder or maybe a set of Binoculars or something.

In my personal experience, you need to cut the coil with a Dremel disk (or another grinder), I tried with side cutters, and just couldn't get it right. Granted, it was al-cheapo cutters.  You also get a better, flatter surface by grinding it off rather than cutting.

[Againstthegrains]

The red bit in the picture. Number 7 if you are colour blind.

In most triggers, the trigger blade and actuator are one unit. When you pull the blade back against a spring, it releases a catch that causes the firing pin to be released. In the case of the HACT trigger, this is now two parts, a trigger blade and actuator. When you pull the blade, it levers against an actuator, and it is the actuator that releases the catch to cause the shot to break.

I think Howa designers made this mechanism in 2 parts as a safety thing, to ensure that there is never any litigation due to misfire. The blade and actuator have their own springs. The blade sits away from the actuator on its own spring, when you pull it, you compress a lighter spring which is the first stage, until the blade makes contact with the actuator. The actuator is on its own spring which controls pull weight, and is adjustable.  Once the trigger blade makes contact with the actuator, the second stage begins, and the blade uses leverage against the actuator to make a crisp break. The break is good, and most people regard it well. The problem that "precision" shooters have with the trigger, is that they:

1. Don't like a two stage trigger, and want to eliminate the 1st stage.
2. The actuator spring is quite hard, so you can never get the pull weight less than 3Lb.

Hence, the drop in trigger blades are an actuator and blade all in one to remove the first stage, or a bushing/spacer goes in to hold the blade against the actuator for the same effect.

 The spring that controls the pull weight is then made lighter as discussed above by others.

[oafpatroll]

In my personal experience, you need to cut the coil with a Dremel disk (or another grinder), I tried with side cutters, and just couldn't get it right. Granted, it was al-cheapo cutters.  You also get a better, flatter surface by grinding it off rather than cutting.

^ This. The spring sits cockeyed if you cut the coil at anything near 90 degrees to the wire. It must be cut or better yet ground flat and at 90 degrees to the coil. 

[jager]

The red bit in the picture. Number 7 if you are colour blind.

In most triggers, the trigger blade and actuator are one unit. When you pull the blade back against a spring, it releases a catch that causes the firing pin to be released. In the case of the HACT trigger, this is now two parts, a trigger blade and actuator. When you pull the blade, it levers against an actuator, and it is the actuator that releases the catch to cause the shot to break.

I think Howa designers made this mechanism in 2 parts as a safety thing, to ensure that there is never any litigation due to misfire. The blade and actuator have their own springs. The blade sits away from the actuator on its own spring, when you pull it, you compress a lighter spring which is the first stage, until the blade makes contact with the actuator. The actuator is on its own spring which controls pull weight, and is adjustable.  Once the trigger blade makes contact with the actuator, the second stage begins, and the blade uses leverage against the actuator to make a crisp break. The break is good, and most people regard it well. The problem that "precision" shooters have with the trigger, is that they:

1. Don't like a two stage trigger, and want to eliminate the 1st stage.
2. The actuator spring is quite hard, so you can never get the pull weight less than 3Lb.

Hence, the drop in trigger blades are an actuator and blade all in one to remove the first stage, or a bushing/spacer goes in to hold the blade against the actuator for the same effect.

 The spring that controls the pull weight is then made lighter as discussed above by others.

Excellent explanation thanks. Now I also know.

For the record, I trimmed a touch more than 1 coil from my actuator spring (While leaving the 2 stage system in place), and the pull weight is now an exact and repeatable 1kg/2.2 pounds.  A perfect weight for a hunting trigger IMHO.

There was some luck though, not pretending I'm an expert gunsmith, my 1st cut, and it came to such a nice round number I decided to leave it right there.

[janfred]

Do you perhaps have the drawing for a Tikka trigger?

[BBCT]

I've never felt the urge to fiddle with the trigger on my Howa. Other rifles yes, but not the Howa.

[Againstthegrains]

Do you perhaps have the drawing for a Tikka trigger?

Is this what you are looking for?