Gunsmithing Triggertech Diamond 2 Stage issue

Roadrace33

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Nov 23, 2023
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I’ve never had this issue before. I just bolted together a new impact 737, 25x47 barrel, and Triggertech diamond 2 stage.

Every 7-8 cycles of the bolt, I get this odd trigger feeling where all of a sudden it’s not a 2 stage. It feels like a single stage, and then just breaks randomly. Like you go to pull for that first stage, and wham, it fires. I’ll attach a video somewhat describing it.
I’ve tried adjusting the weights much heavier with no luck. Tried a different bolt aswell.

I’ve got like 6 of these adjusted waaaay lighter than this, never a single issue.

Bad trigger?

 
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I was promised by a few friends this was a pull weight issue. However, I triple checked. I have adjusted 1st and 2nd stage multiple times, seperately, and the issue is still there. Sometimes it takes 20 cycles of the bolt, but it comes back no matter what. It seemed to go away when I tightened it up to like 3-4 lbs, it took about 60 cycles of the bolt, but I did have one instance with it tightened up that high aswell. So it seems it’s incorporated with something in the trigger that is tied to the weight of the adjustment.

Sent an email and the video to TT. I’ll stop at my local shop today and grab a new one, toss it in and see what happens. I assume it’s just a dud.
 
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Called TT. They told me to flush the trigger.
I stopped by my local guy, he just handed me a trigger to try. Same thing, 2 stage diamond. Tossed it in, dry fired about 20, then fired about 25 rounds. Then when I just was about to wrap it up, it did it again. So I stopped, thinking maybe, somehow it was an issue with a certain case or round somehow. Chambered a different round, and it was fine. So I re chambered the round that gave me the issue, and it was totally fine. So I don’t think it’s a case or round issue. So it seems as if it’s doing it less, but the issue is still there.

Kinda lost. Surely it can’t be an action issue? The pins slide right in the trigger hanger like they would normally. Visually, all the machining on the action looks perfect like the other impacts I’ve got. I’m missing something. I have to be.
 
Do your run the same trigger in your other impact actions? Have you tried this trigger in a different impact action? I have a TT Diamond 2 stage in my Origin action and have not experienced this.
This is my plan tomorrow. I have 4 impacts with this exact trigger, so I’m gonna try it. I love this trigger setup. Never had a single issue. It’s hard to believe it’s an action issue either, because what could be wrong? The trigger is sitting too low and it’s not getting reset perfectly? Maybe it’s as simple as that aluminum trigger hanger impact uses.

It is such a weird feeling because you’re expecting that initial take up of slack, and wham, it’s fired.
 
I feel like I had this happen several years ago with a Diamond and TT warranted it. I can’t remember what they said happened to the trigger, or if it occurred right out of the box or after some use. Sorry I am not much help other than to say give TT a call.
 
I don’t have a gauge to check weight, but a good educated guess would be slightly over 1lb on both stages. It’s not very light at all.

Spent a good hour or two playing with it. I finally figured out how to replicate the symptom. If I slap the bolt down into battery somewhat aggressive, it puts the 2 stage trigger into this “position” that I’m dealing with that is not correct at all.
So I grabbed a second rifle. Did the exact same, slapped the bolt down, and there it was. Did the exact same thing. I grabbed a third rifle. Same thing. It’s really odd I haven’t noticed this until now. Immediately assumed it was a trigger problem. Why it’s doing it, I’m still unsure. Surely people run the bolt WAY harder than this. But, maybe there isn’t as many people running a two stage TT in an Impact.
I do completely understand that there is no reason to slap the bolt down like that, and during live fire I never do. This is however the only way I could seem to replicate the issue last night. I wasn’t about to pop a live round in and start toying with a trigger in my house last night.

A buddy of mine has an impact with a new TT diamond single stage. I seem to not be able to replicate the issue on his. However its single stage, so it would be hard to know.

I will attach another video describing. I have been toying around with a single stage Diamond for a little while. I do like it a lot. I originally made the switch to 2 stage when I got my first AI. (Now I have 2) I liked the idea of all rifles having the same concept of a trigger. However after this debacle, I’m really on the fence and leaning towards heading to my dealers shop after work and exchanging this 2 stage for a single and using it this weekend to see how it fairs against what I’ve been using the last few years, and also if I can get it to malfunction aswell.

I will attach a video of the issue in my new MPA vanquish and also my Samson. Same action same trigger same 75 degree bolt.

EDIT---I wonder if this could be a 75 degree bolt issue in conjunction with a 2 stage TT trigger. I bought my first 75 degree action and bolt a little while back and immediately loved it, and since id switched all mine too it the 75 degree. I sold my 2 original 90 degree bolts to a friend. I could easily borrow his tonight and try and replicate it....I really hope this is not the issue. I have a lot of rounds of the 90 degree bolts, and maybe only 3-400 with a 75 degree.. I fell in love with the 75 Degree immediately.



 
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update-tried both 90 and 75 degree bolts. No change.

Does anyone else run a 2 stage TT in an Impact? I triple checked, tightened the weights way up on 2 rifles last night. Still does the same thing. I put a single stage diamond in and it runs fine. Hard telling if there is an issue because the single stage just breaks right away obviously, there is no slop.

I explained it all to my dealer. He said he’d just swap me straight up for the two stage triggers for new singles, which is great and all but sucks because I’ve grown to like them. I’m going to run a single stage practicing this weekend. I wanted to do the Forster match at the end of the month, ain’t no way in hell I’d take that two stage there.
I’d rather run my AXMC than that unpredictable trigger.

I think I’m going to order a Bix 2 stage. See if it does the same thing.
 
update-tried both 90 and 75 degree bolts. No change.

Does anyone else run a 2 stage TT in an Impact? I triple checked, tightened the weights way up on 2 rifles last night. Still does the same thing. I put a single stage diamond in and it runs fine. Hard telling if there is an issue because the single stage just breaks right away obviously, there is no slop.

I explained it all to my dealer. He said he’d just swap me straight up for the two stage triggers for new singles, which is great and all but sucks because I’ve grown to like them. I’m going to run a single stage practicing this weekend. I wanted to do the Forster match at the end of the month, ain’t no way in hell I’d take that two stage there.
I’d rather run my AXMC than that unpredictable trigger.

I think I’m going to order a Bix 2 stage. See if it does the same thing.
Might also look into the Timney Rem 700 two-stage light....works very well in a CDG.

I do have TT Diamond single stage and, like yourself, I've not had any issues with them.

 
update-tried both 90 and 75 degree bolts. No change.

Does anyone else run a 2 stage TT in an Impact? I triple checked, tightened the weights way up on 2 rifles last night. Still does the same thing. I put a single stage diamond in and it runs fine. Hard telling if there is an issue because the single stage just breaks right away obviously, there is no slop.

I explained it all to my dealer. He said he’d just swap me straight up for the two stage triggers for new singles, which is great and all but sucks because I’ve grown to like them. I’m going to run a single stage practicing this weekend. I wanted to do the Forster match at the end of the month, ain’t no way in hell I’d take that two stage there.
I’d rather run my AXMC than that unpredictable trigger.

I think I’m going to order a Bix 2 stage. See if it does the same thing.
If you are trying a different trigger, look into the Tubb T7T. It is one of the very best 2 stage triggers out there, & it is a true 2 stage trigger.
 
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Had this issue a few years ago with a TT 2 stage, not identical, but very similar.

My issue was to do with the size of the cocking piece as it slides over the top of the trigger sear bar. The bottom of my (PT&G) locking piece was claimed to be oversize and too wide, and it was very lightly rubbing on the green alloy, creating a burr.

Swapped it out for a timney 2 stage, never had a problem since.
 
Does anyone else run a 2 stage TT in an Impact?
I’ve had few, never seen this issue. Ours are all 6-8oz 1st stage, 8-12oz 2nd. With Impact & TT being the most popular in PRS and 1 vs 2 stage being a pretty good mix, I’d suspect this is one of the more common setups.
I moved to BnA Pro X from TT Diamond.
I did the opposite. Sold all my B&A’s and Timney and am now running only TT 2-stages, both Diamonds and Specials on my Impacts.
 
I’ve had few, never seen this issue. Ours are all 6-8oz 1st stage, 8-12oz 2nd. With Impact & TT being the most popular in PRS and 1 vs 2 stage being a pretty good mix, I’d suspect this is one of the more common setups.

I did the opposite. Sold all my B&A’s and Timney and am now running only TT 2-stages, both Diamonds and Specials on my Impacts.
That is kinda what I figured. I really don’t know at this point. These are all relatively new actions. New within the last 8-10 months. I can’t get an answer from TT or Impact. I figured the only thing I can do is try another brand, see what happens. Otherwise, I’m going to single stages for them all, which I’m not upset about. I just wish I could get an answer.
 
I can't replicate your symptom on either of mine. Just to confirm - you have the same issue with two different triggers? Is the hanger installed properly? Clean mating surfaces? Ghetto caliper measurement shows ~0.136” from the bottom of the flat rails to the top of the sear, maybe ~0.015-0.020” below the bottom of the action for your reference. If yours is substantially lower, I’d suspect a hanger or install issue.

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I can't replicate your symptom on either of mine. Just to confirm - you have the same issue with two different triggers? Is the hanger installed properly? Clean mating surfaces? Ghetto caliper measurement shows ~0.136” from the bottom of the flat rails to the top of the sear, maybe ~0.015-0.020” below the bottom of the action for your reference. If yours is substantially lower, I’d suspect a hanger or install issue.

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Trigger hanger is installed correct yes. I was actually able to replicate the issue on all 3 of mine. One of them I only use for hunting, so it has a extremely low round count and this had never happened to it, until now, when i learned running the bolt like that can cause it. The other 2 are target rifles. One of which seems to have this issue much more then the rest. On the new one that i tossed a 25x47 barrel on it was happening probably 4/10 times, so alarmingly enough to where my buddy was like where TF did that round even go because it surprised me so much. However, my other 2 are not nearly enough, and almost seem like you have to get pretty rough with it to replicate the issue, but it is still there. I was thinking a sear engagement issue which is kind of why i was thinking to try a BnA trigger.


I will measure mine once i get home. Thank you for measuring yours to compare.

TT said they would warranty it no problem, but i absolutely cant believe i have 3 bad triggers. Still waiting to hear back from Impact whether they have ever seen this issue.