Tuning Impact Mk 3 trigger pull question

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MikeVV

MikeVV

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Jan 10, 2019
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SoCal, United States
I did some "searching" but didn't find an answer.

I received my Impact Mk3 in .22 the other day. Been experimenting with all of the adjustments. Quite interesting, and sensitive.

My question, like the title notes, the first stage pull is quite hard. Much harder than any of my other guns, including two other FX rifles. It makes feeling the second stage wall difficult. Even after a little lubricating, better, but nearly enough

I did find a YouTube video about changing the spring that controls the trigger. BUT...he did not mention where he got the spring. Just curious if any of you have swapped trigger springs, and if so, where did you get it / what did you use ?

Note - I know, I can measure it and go on a hunt, but...why reinvent the wheel if it's already been figured out ! Like my Walther Reign, it also had a horrendous trigger pull from the factory. I removed the garage door spring and used a ball point pen spring. Made a whole new experience in pulling the trigger.

Thanks ahead of time for any help.



Mike
 
Yes, they used a heavier spring for the trigger in the M3 and it seems for any replacement trigger springs for the MKl and MKll as well?

I did notice the change but I have not set my trigger so light that the second stage break point dissapears as yet.

As you did on your Walther, I have read of some people using the spring from a ball point pen to the lighten the trigger pull.


 
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biohazard -

Yeah, I'll remove the plate and see if I can just measure outer diameter of the stock spring without taking it apart until I have a replacement. I may or may not polish the wheel/disc at the same time.



eh0102 - jking -

No, the second stage is fine as is, crisp, clean and, not a hard pull ! It's the first stage that's heavy. It's a simple lever arm with a return spring. So messing with the second stage, isn't going to effect the first stage very much if...at all. Like I said, the "first" stage is heavy enough that it makes finding the second stage wall difficult. And making the second stage harder...is "not" what I'm looking for.

Thanks

Mike
 
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Well, basically done !

Pen springs are highly varied, in length AND diameter, even among the same brand.

Even the smallest spring was too large in diameter. I picked the softest of the four that I had in hand that I had (a stack of pens from work !). Just by thumb and index finger pressure.

Then I had to shorten it a bit, and close down the end coil to fit into the socket in the gun. Too heavy. I started cutting 1/2 a coil at a time until I found that, yes, I cold actually feel the second stage wall, and still have enough pressure to fully disengage the trigger bar and get it fully back into position to engage the sear into the cutout in the disc.

It's still not close to most of the rest of my guns first stage pull, but it IS about 1/2 of the pull as delivered from the factory. MUCH better, I can much more easily feel the second stage wall now.

So yes, if you don't like the first stage pull of your Impact Mk3 (maybe Mk2), a hand full of pen springs, a small side cutter or dykes and a small pair of needle nose plyers and a fair amount of patients is all that you need.

Mike
 
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Big -

No, I did not see that post, but thanks much for the note.

I saw two problems with that method.

1. There is NO...need to polish the wheel/disc. There is SO...little engagement of the sear when it is adjusted correctly, it's a waste of time. It's difficult to measure deep inside the gun, but I'd guess...at maybe .005" or .006" of an inch, sear to wheel surface engagement.

2. As for shortening the stock spring. What MOST people don't understand, that in shortening a given spring, you ARE NOT lightening the load, or pressure. Springs just don't work like that. All that, that is doing is..."shortening" the spring. Both in the video that I watched and in what I saw on the gun, you are less likely to have the trigger bar go "fully" back into battery position with a "short" spring. And as I said, the spring load has NOT changed at all.

Don't believe me...take a look at ANY compression or extension spring design book, it's right there for all to see !

Plus, like I noted earlier, whom ever did the factory adjustment on my Mk3, did a superb job in adjusting the second stage pull AND sear let-off, so that was not a problem for me. After the spring swap, I did add about a 3/4 turn more first stage movement. But again, that did nothing about the spring load. Oh yeah, the other day, I did lower the trigger shoe as far as it would go to add to the "lever arm" distance. was not really enough to notice.

Mike
 
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mubhaur, corny - 

Thanks for the info, but if you read my last post, a pen spring worked well, and I now have a good second stage "wall" feel.

And also, there's no need to mess with the second stage as it came to me adjusted VERY nicely.

Mike

P.s. - The gentleman above (red lower) created his own problem by using "too..." light a trigger return spring ! I saw that problem when I did the work on mine.

So in effect, not only did he create his own return problem, his "fix" was to modify a part that doesn't have a...problem !
 
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He didn’t create it…that problem exists in the design of the trigger mechanism.

the second stage trigger pull weight is determined by the combined spring weight of the ball detent and the return spring. 

in order to lighter second stage you need to lighten both. 
some ppl prefer a light second stage break. I’m one of those ppl. I was pretty bummed out about the trigger system when I get my first impact. 


 
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May I?

I don't have the M3 but only the MK2. I have polished my trigger parts something similar as EstebanF show it in the other post with some extra steps.

You do your homework with your trigger first stage, I can help you with the second stage ball plunger screw.

A first and quickest fix is lube the ball plunger screw spring inside with something slick, let say ptfe aerosol (I have these for lubing my bike cable wires, brakes, shifter parts).

As a second, you can get these adjustable ball plungers and you can take those apart and modify the length of the pin length or shape as you wish, but the most important is you can polish inside the spring hole.

My trigger parts were polish to an extent that when I get to a second stage and still pulling the trigger per microns I could feel the spring is rubbing inside the plunger screw. I purchased several of the screws from several different vendors hoping different fabrication processes and different spring specs.

plunger screw.1641053088.JPG

 
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I was able to remove the ball from the detent and found that spring was really long having a lot of compression on the spring giving a heavier second stage I used a punch carefully tapped it out shortened the spring about 2 to 3 coils and pushed the ball back into the set screw with shorter spring definitely lightened second stage also polished and lubed sear areas and shortened which helped to I may have to take out the detent and tap it down alittle more to help crimp the ball in place also took the trigger shoe all the way down til it just cleared when cocked second stage is definitely lighter and still has a wall breaks clean but shortening the lower spring seems to have lengthened the second stage some very simple design thanks for the info 


 
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I was able to remove the ball from the detent and found that spring was really long having a lot of compression on the spring giving a heavier second stage I used a punch carefully tapped it out shortened the spring about 2 to 3 coils and pushed the ball back into the set screw with shorter spring definitely lightened second stage also polished and lubed sear areas and shortened which helped to I may have to take out the detent and tap it down alittle more to help crimp the ball in place also took the trigger shoe all the way down til it just cleared when cocked second stage is definitely lighter and still has a wall breaks clean but shortening the lower spring seems to have lengthened the second stage some very simple design thanks for the info 

Click to expand...

Dear,

As you know that I have made a complete new setup for adjusting the plunger spring gradually and as per need of every user.

But I would like to know that the details of procedure that you adopted to lower the spring strength. 

Did you push hard the grub screw from that end in which the alkey enters or you pushed hard the ball into the grub screw.

Will you please elaborate a bit.

What mechanism is inside the plunger screw?

Can you draw pics for my keen understanding?

Bhaur 
 
Upvote 0
I was able to remove the ball from the detent and found that spring was really long having a lot of compression on the spring giving a heavier second stage I used a punch carefully tapped it out shortened the spring about 2 to 3 coils and pushed the ball back into the set screw with shorter spring definitely lightened second stage also polished and lubed sear areas and shortened which helped to I may have to take out the detent and tap it down alittle more to help crimp the ball in place also took the trigger shoe all the way down til it just cleared when cocked second stage is definitely lighter and still has a wall breaks clean but shortening the lower spring seems to have lengthened the second stage some very simple design thanks for the info 

Click to expand...

Dear,

As you know that I have made a complete new setup for adjusting the plunger spring gradually and as per need of every user.

But I would like to know that the details of procedure that you adopted to lower the spring strength. 

Did you push hard the grub screw from that end in which the alkey enters or you pushed hard the ball into the grub screw.

Will you please elaborate a bit.

What mechanism is inside the plunger screw?

Can you draw pics for my keen understanding?

Bhaur
Click to expand...

I took a small punch and went threw the side the Allen wrench fits on and tapped it out it is just a hollow set screw with a ball and spring
 
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Please forgive my art I shortened the small spring so it was just maybe a coil or to two over the hollow set screw with the ball and spring back in place I tapped it back together on a hard surface to put some bend back onto the part that holds ball into place the small spring in place is pretty long I was surprised at the length of it I also shortened the other trigger spring and polished engagement areas of the trigger carefully not to change any angles just to smooth it out then just dropped the trigger shoe to as far down as I could and still clear when cocking 
 
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