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Which do you favor?

  • SEI Trigger Job

    Votes: 4 12.9%
  • Shooting Sight RPS Adjustable Trigger/Hammer Set

    Votes: 22 71.0%
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    Votes: 5 16.1%
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Discussion Starter · #1 ·
I wanted to know the opinions of the forum in regards to a trigger upgrade. I'm not quite at the point yet, but I foresee upgrading the trigger on my JRA M14 in the not-so-distant future. I've narrowed it down to two options, though I'm open to hear others.


SEI Trigger Job

Or,

Shootingsight.com RPS adjustable trigger/hammer set:

https://shootingsight.com/product/nm-m14m1am1-garand-trigger-and-hammer-set-2/



Does anybody have experience with either of these and what were they?

Eager to hear everyone's opinion :)
 

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That's a good question.
I've got an SAI M21 with a Very smooth/crisp trigger on it. For an M14, I'd say it's pretty sweet, but I'm used to much lighter triggers on all of my other rifles and the idea of the Shooting Sight trigger being adjustable down below 4lbs, really has my attention.

I'm thinking of picking up parts and a Shooting sight trigger and hammer for a 2nd trigger assembly.
 

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ShootingSight is your ticket, I will be getting one in the near future myself.

Ren
 

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I am in favor of adjustable triggers when possible. The RPS/Shooting Star unit looks really interesting and would be my choice.

Back in 2009, for my M21 SAI Tactical Match I bought one of SAI's M25 "Adjustable Match Triggers" (as then offered in the M25 White Feather rifle). Pull is adjustable from 4.5 down to 1.5 pounds, but I keep mine at 3 pounds. It is a joy to use, but one must be very cognizant of how much shorter and lighter the trigger pull if you are used to shooting "regular" M1 and M1A triggers - as its basically a single stage trigger. However, SAI discontinued the M25 trigger groups around 2010, and today they are hard to find and rather pricey, so I think the RPS unit is probably the best option these days.

FWIW, here's a picture of my experiment - a reverse engineering of the SAI M25 trigger group (my original M25 'White Feather' group is in back, experimental unit in middle, and standard SAI commercial group in front). If you look closely at the SAI M25 group you can see the small coil springs on top of the trigger part itself (Note: each side of the trigger has one of these small springs to provide positive upward sear engagement pressure on the bottom of the sear part connected to the trigger).



The internals have been removed in this picture, but inside the rear 'mounting block' is another larger coil spring with a rounded plunger that provides adjustable pressure on the rear 'bow' of the trigger part. A set-screw on top of the mounting block can be loosened and an allen head wrench can used to subtly move up or down the threaded screw in the block, thereby providing an adjust the trigger pull b/t 4.5 and 1.5 pounds (at least in theory).



The key to these "M25" adjustable M1/M14 triggers to get the right level of 'pre-load' on the trigger while still maintaining sufficient sear engagement surfaces/holding pressure. This requires 3 additional springs, a custom trigger, and a custom housing block for the plunger assembly (2 small springs in the trigger itself and one spring in the housing block for the trigger pull adjustment). Traditional/original M1 and M14 trigger groups can not safely be 'tuned' for trigger pulls below 4.5 pounds as the sear angle and its holding pressure/engagement surface is not sufficient below that - which can lead to "doubling" or other dangerous conditions...

The experimental design shown here differs from the SAI part in that the block is machine screwed on from the bottom rather than welded-on to the housing, and a USGI trigger is modified for two tiny springs rather than the custom trigger part that SAI made for their unit. SAI also uses a customized spring plunger housing, but the one I made made used the standard part without modifications.



For this project I bought a couple of SAI commercial trigger groups for $130, as I did not want to drill-and-tap into a valuable USGI trigger housing for this type of modification. Unfortunately the retired and very talented machinist who made these parts for me developed serious health issues (cancer), and made me only this one unit thus far, but I wanted to at least show how these systems work. (Btw, please don't ask if I can provide you with these parts - as I unfortunately don't have the tooling or machine skills to duplicate this type of work, nor do I have the specs re the springs...It took many months of reverse engineering to make just that one prototype).

Anyhow, the RPS unit would be my choice and gets my vote in this thread, for its adjustability.
 

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Have to say , of the two, Shooting Sight. Art has done a great job with his products. I have two of his setups with his lightened hammer and adjustable triggers and they work as advertised.

Semper Fi
Art
 

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One more on the shooting sight bandwagon.

Never tried an SEI trigger job, but the ability to adjust, to me, is reassuring, as I found out, in that adjustment, that what I actually wanted wasn't necessarily what I thought I might have wanted. Specifically, for me, for that rifle, I kept the trigger pull on the higher side of the adjustable range, as I preferred the feel of both the first stage and the break that way.

In my SAI trigger housing, the adjustable trigger did not make my trigger equivalent to the 'pressure sensor' kind of feel of my modern bolt guns, but it was, for me, a vast improvement over the SAI 'National Match' trigger job that SAI provided. That being said, there is always variation in both process as well as preference, so somebody could get a trigger job from XYZ that they prefer over anything they get anywhere else, but the Shooting Sight trigger gives you the broadest spread of options I know of, where you get to figure out how you like it best, as opposed to somebody telling you what's best for you, which often, if not usually, isn't the case.

The fact that it allows you to examine the intricacies of how the trigger mechanism works, that the parts are built and hardened as they are, as opposed to being modified, and the faster hammer fall, are all bonus.

Be aware, that the speed hammer, being lighter, is designed to compensate for the lower mass/inertia that allows the quicker hammer fall, in terms of energy transfer into impact on the firing pin, by increasing the leverage of the hammer spring on the hammer (which also makes it faster).

There is no detriment to trigger pull at all in this arrangement, but you will notice that engagement/disengagement of the safety will require more force, as the safety has to push the hammer back just a little bit farther.
 

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For an M14, I'd say it's pretty sweet, but I'm used to much lighter triggers on all of my other rifles and the idea of the Shooting Sight trigger being adjustable down below 4lbs, really has my attention.
When I received my hammer/trigger set the instructions stated it was engineered to operate at 4-1/2 lbs and was not was not designed, nor was it suggested to adjust below 4lbs due to potential reliability issues. Can anyone confirm if this is still true?
 

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yup
 

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When I got my M21 it had a sweet trigger feel and was just under 4.5 lbs.
This Winter when working up loads for it, it doubled twice and I proceeded to
tune it back up to 4.75lbs where it is supposed to be.

The issue I have is this...
I liked the feel MUCH better at just under 4.5 than now and the rifle, or I, shot better with the lighter trigger, until it started doubling. That's why I want to give the Shooting Sight a try.
 

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I have a couple of the shooting sight trigger/hammer sets, and also have a trigger group that sei did the max-pak trigger job on. They are both great feeling and functioning triggers. If I had it to do over again, I would get the shooting sight adjustable trigger and speed hammer instead of the sei max pak.
The sei trigger job was good, but for the price they charge for it, I expected more.


Another option is have Jon Wolfe do your trigger job and then nitride the parts that can be nitride treated. This would be cheaper, and probably even better than the sei work.
 

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Thanks for all the support. There are a couple of things I want to clarify:

1. Yes, I designed the trigger to get down to 4-1/2lb, because that is the majority of my customers, who are limited by the NRA's minimum of 4-1/2lb in the service rifle class. I was also concerned with reliability going much lower. I wanted this to be a drop-in trigger with little smithing required. Anyone who has worked on these triggers knows that there are lots of areas where hole alignment in the housings, or hole diameter on one side, can be off, causing pins not to be parallel, and you get rubbing of internal components.

If you go too low in weight, this rubbing can cause the trigger to not reset properly. So I made it to get to 4-1/2 and left it there. If I went lower, you just know that somewhere would be that 'one guy' who tried to see how low he could go, and get a trigger that isn't functioning properly .... which is a liability I'd rather avoid.

That said, and as TonyBen confirmed, if you set mine to the minimum AND go the extra mile to polish/grind etc to make sure everything else in the guts is not rubbing, you can likely break into the high 3# range, but that is it without a spring redesign.

2. I am surprised to hear anyone has been able to make one of my triggers double. The disconnector is redesigned exactly to give better engagement on recock than the USGI design, so I had not heard of anyone being able to do that.

3. Rader triggers, with the towers at the back of the housing, were nice triggers, but took a lot of work. Today, the hammer spring also acts as the trigger spring and the second stage spring. Rader:
a) modified the spring housing so it would NOT bear on the disconnector (ie took the hammer spring out of the equation).
b) drilled into the back of the trigger, under the disconnector legs, to insert two 1/16" springs acting on the underside of the disconnector to replace the second stage springs.
c) added the tower at the back of the housing with a srpring pushing down on the tail of the trigger to replace the trigger spring. My hat is off to him, not only for a clever design, but for making it in the context of starting with USGI parts, where you can only remove material from a USGI trigger - you cannot add anything back in. My triggers are made from scratch, so I have the ability in my design to add thickness or features - he did not. Unfortunately, these were so expensive, they didn't survive the market. I have one I bought while I was doing development on my trigger, and think I gave $600 for it on the used market.
 

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Thanks for all the support. THere are a couple of things I want to clarify:

1. Yes, I designed the trigger to get down to 4-1/2lb, because that is the majority of my customers, who are limited by the NRA's minimum of 4-1/2lb in the service rifle class. I was also concerned with reliability going much lower. I wanted this to be a drop-in trigger with little smithing required. Anyone who has worked on these triggers knows that there are lots of areas where hole alignment in the housings, or hole diameter on one side, can be off, causing pins not to be parallel, and you get rubbing of internal components.

If you go too low in weight, this rubbing can cause the trigger to not reset properly. So I made it to get to 4-1/2 and left it there. If I went lower, you just know that somewhere would be that 'one guy' who tried to see how low he could go, and get a trigger that isn't functioning properly .... which is a liability I'd rather avoid.

That said, and as TonyBen confirmed, if you set mine to the minimum AND go the extra mile to polish/grind etc to make sure everything else in the guts is not rubbing, you can likely break into the high 3# range, but that is it without a spring redesign.

2. I am surprised to hear anyone has been able to make one of my triggers double. The disconnector is redesigned exactly to give better engagement on recock than the USGI design, so I had not heard of anyone being able to do that.

3. Rader triggers, with the towers at the back of the housing, were nice triggers, but took a lot of work. Today, the hammer spring also acts as the trigger spring and the second stage spring. Rader:
a) modified the spring housing so it would NOT bear ont he disconnector (ie took the hammer spring out of the equation.
b) drilled into the back of the trigger, under the disconnector legs, to insert two 1/16" springs acting on the underside of the disconnector to replace the second stage springs.
c) added the tower at the back of the housing with a srpring pushing down on the tail of the trigger to replace the trigger spring. My hat is off to him, not only for a clever design, but for making it in the context of starting with USGI parts, where you can only remove material from a USGI trigger - you cannot add anything back in. My triggers are made from scratch, so I have the ability in my design to add thickness or features - he did not. Unfortunately, these were so expensive, they didn't survive the market. I have one I bought while I was doing development on my trigger, and think I gave $600 for it on the used market.
Art,

To be clear, I set my trigger to have no second stage creep. Once the first stage slack is taken up (which feels so smooth, it's like a spring loaded trigger floating in the air) I have the second stage set to break instantly with that last pound or so of pull. When Phil dry fired it, the break really really surprised him.

I've put hundreds of rounds through this rifle and only doubled once or twice off the bench. I am sure that with a conventional trigger job, I'd be doubling all the time.

Tony.
 

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Eye Master
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On the M14 trigger, the angle of the discon face determines the position of the sear at the moment the hammer releases, while the tip of the discon determines the position of the sear at the moment the trigger resets. So how 'steep' the face of the discon is drives that difference and allows for an overlap of the trigger sear with the hammer at the moment the trigger resets.

More vertical face makes the difference smaller, which I believe is the reason you can double a USGI trigger.

The USMC TM for match rifle prep makes the face of the discon slightly more inclined. My design makes it even more inclined than that. This is why mine normally will not double if set up properly.
 

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Discussion Starter · #18 ·
Well, I think I have a clear answer based on all of the feedback. I'm glad to hear this. I was leaning towards the adjustable set, but I was worried that it was too good to be true. Seems it's living up to the hype in my head.

One thing I was wondering, and perhaps Art is the best person to answer this, is if the adjustable trigger set does anything for travel. The trigger that came with the JRA is different feeling than the one on my M1. On the JRA, there is practically no first stage (it is very, very short - around a millimeter or so) and then a little creep before the trigger breaks. After follow through, there's what I would consider to be a notable amount of travel until the reset. I imagine that by both replacing the trigger and hammer with the adjustable set, that should eliminate the strange first stage and the creep thereafter. I wonder if it will affect the travel to reset.
 

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I have one of my Shootingsight trigger/hammer in a Bula trigger housing with Bula trigger guard. The rest are usgi spring housing, shooting sight plunger, usgi safety spring, and a usgi winter safety. It works great for me. It should be ok for you too. Only issue I had was the Bula hammer spring housing. It would not fit over the shootingsight trigger, but usgi did. I may have just got a bad one. I used a Tubb's hammer spring. I may try a usgi spring later, but really have no reason to other than to just try it. I plan to get one of the EBR triggers and another speed hammer before long for a pistol gripped M14 I am building.
 
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