Heavy trigger when unset?

[aephilli822]

Investarms 50 Hawken. When I set the trigger it has a nice, light pull. When I try it unset it feels like it must be over 10 lbs. :confused:
When looking at it disassembled, it seems very stiff when trying to "fire" the lock by pulling on the sear arm.
I've seen the Davis "Deerslayer" trigger recommended (not liking the look of the flat front trigger, but who knows, I've never tried one), but is that gonna help if my sear is actually heavier than "normal"?

[NSB]

Your set trigger sounds like just about every set trigger I've ever used on a medium priced rifle. They are almost always a bit heavy without being set. That's the entire idea about having a set trigger.....to make them very light after being put in the set position. If you don't like set triggers, an aftermarket single trigger will probably work out better for you. Just don't expect it to be as light as your set trigger was...as light and still safe.

[waksupi]

Your trigger is functioning normally.

[aephilli822]

Good to know, thanks.
so for 50 bux I can get the Davis and it may have a better unset weight. or I can carefully try to smooth the engagement surfaces to reduce it a little.

[Omnivore]

You may be confusing the trigger with the tumbler/sear interface.

Firing from the set position, you're releasing only the rear trigger (a mechanical relay) which slaps the sear arm to release the tumbler. In that case you're not working the sear arm directly, or even touching it, with the front trigger. When firing from the UN-set position, you're pressing front trigger directly onto the sear arm to release the tumbler, and thus you are feeling the actual sear/tumbler interface via the front trigger.

If leaving the sear and tumbler alone and replacing the trigger only, very little can change. Just about the only way that can make any difference at all is to have a trigger that's pinned higher or lower, providing more or less leverage against the sear arm, and/or if the trigger return spring is lighter or heavier.

But there is another factor, which is often over-looked. That is the location of the front trigger pivot in relation to the sear arm pivot, and that difference can result in more, or less, "scrubbing" between the front trigger arm and the sear arm. The more scrubbing, the more nasty the trigger feel will be, all else being equal.

The primary determiner of the un-set trigger pull though, is the tumber/sear interface, in most cases.

So it is that if you want a lighter, or otherwise better (e.g. having less creep) un-set trigger, then the chances are you'll have to do, or have done by someone else, a re-working of the tumbler and sear.

IF your mainspring is very heavy, one simple way to improve your un-set trigger feel would be to lighten the mainspring. That reduces the pressure between tumbler and sear, and thus the trigger pressure required to release the tumbler. Another, similar way would be to reduce the sear arm spring tension, but you must understand that in doing any of these things there is a safety issue which should be kept foremost in mind. You could be setting yourself up for a disaster.

In short; you should probably be looking more at the lock itself and not so much at the trigger, AND you should fully understand the interactions of the lockwork before doing anything, or take it to a real gunsmith.

For further study;
The good old single trigger is often pinned into the wood as high as possible, giving it superior leverage against the sear arm. The double set trigger, and some single triggers, are pinned very low, into the trigger plate itself, giving relatively poor leverage. In the latter case, a lighter sear/tumbler release is necessary for a good trigger feel, and that's a bit less safe than having a heavier sear/tumbler release with a higher pinned trigger.

And anyway; the other way to look at this is to consider adjusting the set trigger release such that it presents a bit less of a hair trigger response, and/or increase the trigger return spring tension, which would increase the pull weight of the front trigger whether firing from the set or the un-set positions, and then use only the set position.

There are a lot of ways to look at this, and I would gather from your initial question that you should spend some time studying the classic lock designs and functions before you leap too far. In the meantime, back the set trigger adjustment screw out a bit, and stick with firing from the set position.

It is a fact that most people will shoot better, initially, with a very nice trigger. HOWEVER, a heavy trigger does not in any way mean that you MUST shoot less well. It's mostly a psychological factor, which can be largely overcome with practice.

[Omnivore]

Actually, Waksupi's answer may be the best one; "Your trigger is functioning normally."

[gonetocamp]

I installed the Davis Deerslayer trigger in a Lyman Great Plains Rifle which is made by Investarms. The Davis did not reduce pull weight but it, thankfully, does not have the long take up found in the Investarms unset front trigger. My goal was to hunt with the front trigger unset. I stoned areas of the lock where I thought friction could occur. But, the best thing that I did was to replace the heavy sear spring with a lighter weight spring. The standard ink pen spring diameter is too large but I found some smaller pens that used a smaller diameter spring (the outside diameter must fit inside the sear spring housing). I am satisfied with the unset front trigger pull weight. I do recommend the Davis Deerslayer trigger as it does away with the long take up present in the Investarms unset front trigger. However, I would suggest replacing the sear spring first, as you may then want to keep the Investarms triggers.

[aephilli822]

You may be confusing the trigger with the tumbler/sear interface.

......

GREAT info & details. most of that I (think I) had (sort of) figured out, but I'm saving that in a document for future reference. all due caution to be ensured when mucking about with the trigger/lock works

thank you again for the info

[aephilli822]

Actually, Waksupi's answer may be the best one; "Your trigger is functioning normally."

that's what I thought, just VERY heavy, thanks for the confirmation

[aephilli822]

I installed the Davis Deerslayer trigger in a Lyman Great Plains Rifle which is made by Investarms. The Davis did not reduce pull weight but it, thankfully, does not have the long take up found in the Investarms unset front trigger......

also good info, as (I think) where the trouble is, is not the trigger but the amount of force needed to move the sear
thanks (your first post and you've already helped someone!)

[aephilli822]

also, the trigger when set is pretty light, but not what I would call a "hair" trigger (not anywhere near a Canjar when set)

[Maven]

One additional problem with Investarms' triggers is the set screw on the bottom of the trigger plate. It's too short and is an odd thread to boot. I.e., you can't manipulate as you can with a Thompson Center trigger to make the main trigger (when set) a "hair trigger." Dixon's in PA has those longer screws, btw. Polishing the lock innards also helps reduce the pull of the main trigger when set.

[rfd]

the investarms dst is like most coming from italy or spain and all can be made to feel smoother by cleaning out the entire trigger set with any form of moose milk and a toothbrush, pat off the excess, a light fine stone *polishing* (no filing) all moving parts' bearing surfaces, then clean with only tap water and a toothbrush, fully dry off, spritz well with wd40, pat off the excess with a paper towel, then use a good grade of oil (like a super lube w/teflon, or better yet tsi-301 or tsi-321) on the bearing surfaces. there should be a noticeable added smoothness to the set trigger or fire trigger when not set. make sure the lock is at least well washed and scrubbed with moose milk, pat off the excess, fine grade oil all bearing surfaces. doing both should make for an all around better trigger & ignition system.

[aephilli822]

the info about not being a "hair" trigger is not a complaint, just info. I actually like it when set as is, just need the unset to be less than the 9 (NINE :groner: ) pounds my fish scale shows it to be....

that was gonna be the next step, cleaning and then polishing the all the surfaces. where the front trigger arm touches the sear arm they are both pretty rough looking

[Col4570]

Very often as the tumbler is rotated and the sear slides over it a Bur occurs on the full cock notch.This may cause the sear to hook under the Bur rather than slip off it easily.a hard trigger pull can be the result.

[aephilli822]

Very often as the tumbler is rotated and the sear slides over it a Bur occurs on the full cock notch.This may cause the sear to hook under the Bur rather than slip off it easily.a hard trigger pull can be the result.

First thing to look at, thanks