SmithSights Mosin-Nagant Trigger Spring
A trigger spring is an easy, cheap, and therefore common modification to the Mosin-Nagant trigger group. The original Russian design doesn’t include a trigger spring, but adding a spring into the trigger’s guts will take up some of the slack and some springs will actually drop the pull weight by a small amount. I’ve had several Mosins over the years and I feel confident saying I’ve spent time firing the majority of the market when it comes to the bang button on the Mosin-Nagant, from DIY polish jobs up to and including the crème-de-la-crème Timney single-stage and M28-76 two-stage. So, when Josh Smith at SmithSights offered to send me a prototype of his newly improved trigger spring, I was intrigued.
The SmithSights trigger spring is modeled after the Finnish M28’s trigger spring. This type of trigger spring installs from the rear and pushes the trigger forward to eliminate slack, and so physics says that this type of trigger spring should not reduce the pull weight since it is ADDING spring pressure to the trigger pull (although this is not what I always found, more on that later). There is a second type of trigger spring for the Mosin that installs from the front and pushes the trigger backward to eliminate slack. This second type of spring is what I use when I customize a Mosin trigger, so I was interested to see how the SmithSights spring would compare.
To test the SmithSights trigger spring versus the “other” type of trigger spring I use now, I installed both spring types on a completely factory Mosin trigger group and measured the pull weight on a fish scale-type trigger pull gauge. I then swapped out the factory Mosin trigger group for my own customized parts and repeated the tests, just to see if there was any difference (and there was). Each trigger setup was tested at minimum three times to ensure the reading was correct, usually more.
Installation, Fit, and General Thoughts
The SmithSights trigger spring is extremely well thought-out. Part of the credit goes to the Finns who came up with the idea decades ago, but I also credit SmithSights for executing the design with quality manufacturing and, as of this most recent version, a few improvements. I’ve had nothing but good experiences with SmithSights in the past, and this new trigger spring is no exception. When it comes to Mosin parts and upgrades, Josh at SmithSights knows what he’s about.
On to the details. The black “other” trigger spring I’ve been using up to this point is bent from much thinner gauge steel than the SmithSights spring. As a result, the SmithSights spring is stronger and beefier, but the two springs are fundamentally different designs and can’t be directly compared in terms of strength. The SmithSights spring only compresses a small amount, and only after the trigger is pulled, while the “other” spring is installed in a highly compressed state. If the “other” spring was as stiff as the SmithSights springs, it would definitely put the rifle at risk of accidental discharge.
Both springs have four coils and L-shaped bends at the end of the spring legs.
Feast your eyes on some side-by-side comparison shots:
The SmithSights trigger spring is extremely well thought-out. Part of the credit goes to the Finns who came up with the idea decades ago, but I also credit SmithSights for executing the design with quality manufacturing and, as of this most recent version, a few improvements. I’ve had nothing but good experiences with SmithSights in the past, and this new trigger spring is no exception. When it comes to Mosin parts and upgrades, Josh at SmithSights knows what he’s about.
On to the details. The black “other” trigger spring I’ve been using up to this point is bent from much thinner gauge steel than the SmithSights spring. As a result, the SmithSights spring is stronger and beefier, but the two springs are fundamentally different designs and can’t be directly compared in terms of strength. The SmithSights spring only compresses a small amount, and only after the trigger is pulled, while the “other” spring is installed in a highly compressed state. If the “other” spring was as stiff as the SmithSights springs, it would definitely put the rifle at risk of accidental discharge.
Both springs have four coils and L-shaped bends at the end of the spring legs.
Feast your eyes on some side-by-side comparison shots:
Installing the SmithSights spring is astonishingly simple. Just pop your action out of the stock, loosen your trigger screw, push your trigger axis pin partway out, drop the spring in place, and tap the axis pin back in. Retightening the screw compresses the spring and completes installation; you don’t actually remove anything except the stock. The real beauty of this process is that the spring isn’t under tension until the screw is tightened, so it just plops into place with a minimum of fuss. There is a tiny bit of wrangling to get the coils around the axis pin, but that's it.
By contrast, the “other” trigger spring is a pain in the patoot. It is installed under a great deal of tension, and is pulled into position by looping string (or in my case, a very thin zip tie) through the coils and pulling it into alignment with the axis pin. One wrong move and the spring goes flying during both installation and removal.
So the SmithSights spring is easy to install and takes the slack out of your trigger, but does it actually lighten the pull? Let’s find out. Here is my ratrod Mosin, which will host this trigger party:
Testing the Factory Trigger Group
The first step was to swap out my own custom trigger group for a completely factory Russian trigger group. The factory trigger group was from an Izhevsk hex receiver (in case you wanted to know) and measured in at 5.75 lbs on the scale, with no springs installed. That’s a pretty nice trigger, as factory Mosins go, and testament to the notion that pre-war hex receivers ain’t too shabby.
The first step was to swap out my own custom trigger group for a completely factory Russian trigger group. The factory trigger group was from an Izhevsk hex receiver (in case you wanted to know) and measured in at 5.75 lbs on the scale, with no springs installed. That’s a pretty nice trigger, as factory Mosins go, and testament to the notion that pre-war hex receivers ain’t too shabby.
Next up, I installed my “other” spring and re-tested. The reading was slightly lower, around 5.625 lbs. Not much, but something.
Next, it was the SmithSights spring. Much to my surprise, the gauge measured a drop of more than a quarter pound, slightly below 5.5 lbs. This seemed all but impossible, but multiple retests confirmed that even though the SmithSights spring was pushing the trigger forward, the pull weight actually dropped. I can only surmise that the tension from the spring is lifting a formerly pinned part, reducing friction somewhere unseen in the trigger group mating surfaces, resulting in a small but noticeable decrease in pull weight.
So on a factory Mosin trigger group, the SmithSights spring produced a noticeable but maybe not noteworthy drop in pull weight. How about my customized trigger group?
Testing the Custom Trigger Group
Without any spring in place, my trigger group registers 3.5 lbs, give or take a few ounces. I won’t share the details of how I modified my trigger group. I'm sure there are folks on the internet who will happily show you various ways to grind or polish your trigger parts, but I will not partake in teaching people only enough to be dangerous.
Without any spring in place, my trigger group registers 3.5 lbs, give or take a few ounces. I won’t share the details of how I modified my trigger group. I'm sure there are folks on the internet who will happily show you various ways to grind or polish your trigger parts, but I will not partake in teaching people only enough to be dangerous.
Installing the “other” trigger spring offered up pretty much the same result. This setup (custom trigger parts and “other” spring) is what I normally shoot this rifle with and I’ve been quite happy with it. The modifications to the trigger group impart some extra looseness in the already slack factory trigger, and adding the spring tightened it up into a smooth, crisp 3.5 lb single stage trigger.
Installing the SmightSights spring into my custom trigger group finally presented with a result that made sense. The pull weight increased sharply, spiking to about 4.325 lbs, nearly a full pound higher. As to why the SmithSights spring’s forward tension only makes an appearance when the trigger is lightened through other means, I can only guess that lightening the trigger pull allowed the forward pressure of the SmithSights spring to become a dominant, measurable force in the trigger’s resistance, whereas in a factory trigger that spring tension is largely lost in the "noise" of the heavy, friction-laden trigger pull.
So what’s the takeaway?
Well, I’m pretty impressed by the SmithSights trigger spring. If you’ve got a factory trigger group, there’s really no reason not to buy this little upgrade. It’s robust, easy to install, greatly improves the trigger’s feel, and even offers a small drop in pull weight (somehow). And the cost is dead reasonable.
For those of us with custom triggers, I’d recommend the SmithSights trigger only if you are comfortable doing your own trigger work. If you bought an off-the-shelf trigger or had a smith do the trigger job for you, it’s likely that adding the SmithSights spring will just increase your pull weight. The “other” spring, which can be found on Amazon or eBay, will tighten up the trigger’s slack without substantially impacting the pull weight, and is probably the better buy.
But if you do your own trigger work, then I believe the SmithSights spring is the better option. Now that I have a spring that applies forward pressure, I feel more confident in pushing the factory trigger to the limits of its design, and will be back in my shop tomorrow with tools in hand. Sure, the SmithSights spring adds pull weight, but if you tune to compensate for that you’ll wind up with a safer rifle, because a 3.5 lb Mosin trigger that’s being pushed forward, firmly, is safer than a 3.5 lb trigger that’s being pushed backward, lightly.
In summary:
Happy shooting.
Well, I’m pretty impressed by the SmithSights trigger spring. If you’ve got a factory trigger group, there’s really no reason not to buy this little upgrade. It’s robust, easy to install, greatly improves the trigger’s feel, and even offers a small drop in pull weight (somehow). And the cost is dead reasonable.
For those of us with custom triggers, I’d recommend the SmithSights trigger only if you are comfortable doing your own trigger work. If you bought an off-the-shelf trigger or had a smith do the trigger job for you, it’s likely that adding the SmithSights spring will just increase your pull weight. The “other” spring, which can be found on Amazon or eBay, will tighten up the trigger’s slack without substantially impacting the pull weight, and is probably the better buy.
But if you do your own trigger work, then I believe the SmithSights spring is the better option. Now that I have a spring that applies forward pressure, I feel more confident in pushing the factory trigger to the limits of its design, and will be back in my shop tomorrow with tools in hand. Sure, the SmithSights spring adds pull weight, but if you tune to compensate for that you’ll wind up with a safer rifle, because a 3.5 lb Mosin trigger that’s being pushed forward, firmly, is safer than a 3.5 lb trigger that’s being pushed backward, lightly.
In summary:
- Completely factory trigger group OR self-modified trigger group = SmithSights spring
- Smith-modified or off-the-shelf trigger group = “other” spring
Happy shooting.
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