Home Forums Hunting & Shooting Savage Collectors Learning about trigger, sear, springs, interfacing surfaces

I reworked a trigger today by applying a theory I broached a while back. Of course, this is always a popular topic.

Relax, I'm screwing around with a junk parts gun just for the sake of better understanding the workings of the 1899. I'm putting myself thru Savage university by playing with the various parts and their interaction. Beats sitting in the house watching Cinderella, (literally).

Do not take this as any kind of endorsement to screw with your gun. I am afforded the luxury of having a junker to play with, so no loss if I ruin a $20 part and have to replace it, which I would in a heartbeat if I ruined anything. That said, check this out.


I had a damaged but functional sear for an 1899 so I rounded it off where it mates with the firing pin sliding surface. Now instead of two flat surfaces making contact and sliding off each other when the trigger is pulled, I removed two thirds of the width of the sear mating surface by rounding the corners off and polished the remaining 1/3 with fine emery cloth.

I also shortened the sear a little to shorten trigger travel, which was horrendously long.The mating surface on the firing pin remains unchanged as no advantage can be gained there and potential problems abound by modifying that.

Once sear and bolt are installed and gun is cocked, and with the stock off, I pounded on the tang using a wood mallet to try to get a slamfire. None. End of barrel, none. Wailed on it harder than you ever would by dropping it. No slamfire. In fact, the trigger and sear remained stationary with no movement at all toward a slamfire. Who knows, the next rifle you try it on may slamfire with little effort, but this one won't. Every rifle is individual that's why you should not try this with yours. Did I mention do not try this with yours?

By reducing the width of and polishing the sear with fine emery cloth, as well as shortening it, the trigger travel was reduced to a reasonable distance, more in line with other Savages I own, and while the trigger pull is very heavy, it is very smooth. It seems as though the trigger weight is mostly a function of the firing pin springs resistance rather than the trigger spring. The trigger spring just holds the trigger in the forward position more than anything.

Reducing trigger pull weight is a conundrum. If you reduce tension on the firing pin spring by clipping coils you'd risk light strikes on the firing pin primer. Does not seem a reliable solution and also perhaps fraught with peril. But, I may try it just because that's how my mind answers these questions. I have only the cost of parts and a little time to lose. Please don't misread this as an endorsement to attempt this. I'm just throwing it out there as an academic exercise. Honestly, I don't think most people have the aptitude or patience for this type of thing. I happen to enjoy learning things like this, but it's not for everyone and it does cost money and take time, as well as clutter a large area in the shop.

Hopefully I will not be tarred and feathered and runnoft.

Interesting and I’ll leave that feathering and tar thing to someone else. I may also make a comment but that will have to wait until after having a cup of inspiration tomorrow morning.

I have a chicken farm nearby that has an endless supply of feathers, and I prefer to use wood glue instead of hot tar (there's no need to cause Roy cruel or unusual pain, just the public shaming is enough).

But, all seriousness aside, I freely admit to being a 99 hobbyist/amateur tinkerer, and claim as much whenever I sell a rifle or parts, if I've dinked with it, (Thanks Larry Potterfield!). So, I appreciate Roy's exploration, and full disclaimer, of a subject near and dear to us all.

Are we forgetting the role real gunsmiths here? Those trained, experienced, and licensed 'smiths hold a great deal of collected wisdom. I think a good follow-through for this sort of discussion would be to have a licensed gunsmith examine Roy's work, and possibly even certify it.

That still doesn't make Roy's work universally acceptable, but we often field the question of "finding a qualified 99 gunsmith". We might be able to contribute to the greater good, by learning more about 99s then passing it on.

The first question that popped into my head was what might happen down the road 10, 20, 30 years later after significant/hard use. Will the newly configured assembly wear "properly" and not in a manner that induces a slam fire?

Were the sear surfaces made of high quality tool steel and through-hardened or were they made of lesser steel and merely given a good thick case hardening? That would have a bearing on how much meat can be removed- again with long term use wearing through the remaining structure more rapidly than normal if indeed we're talking case hardening, leading to Roy's tar and feathering (albeit by our grandchildren going after his grandkids).

So, were you the guy who runnoft with Mrs. Hogwaller?

Roy, I have run into maybe a half dozen lever safety guns with trigger/sear mods that made them unsafe. One thing most of these had in common is that during the cycle of closing the lever the sear engagement was reduced to mere thousandths of an inch. There is much greater sear engagement when the lever if fully closed. Watch this engagement as you close the lever and see if you observe what I did.

I applaud your experiment. I would just admonish you to not put the gun in other hands without restoring it with factory original parts.

I'm having trouble loading photos for some reason. I'll keep working on it.

As for wear, the center remaining 1/3 of the sear is polished only and otherwise untouched, so whatever hardening was there is still there. I don't personally believe wear is going to be an issue. "hard use"? Not sure how you use a trigger harder at one time or another, although an undue accumulation of dirt would qualify. Looking at sears I've never seen any evidence of any wear on even the oldest ones. I don't think it's a high wear piece.

Hogwallop. She was hot. We done runnoft.

I always appreciate Roy’s willingness to “take a look under the hood.” My general observations have been that earlier 99s (say those built prior to WWII) have quicker triggers than later 99s. That is later 99s have much more creep. I don’t know about the rest of you guys but I’ve heard stories of 99s back in the day having a bit of a slam fire reputation that would happen if the butt took a strong hit. Granted all it takes is one bad occurrence to make a reputation. But I also figured that the creep added to the 99 trigger mechanism was a response to that problem, I.e., more surface contact area made for a more positive lock up.

I am unclear on one point. When you say you reduced the contact area by rounding off the corners did you mean the corners as if you were looking straight down on the the sear? My only concern with that is it could add some sideways movement to the mechanism that was never part of the original design and that may cause some issues elsewhere.

Mike, if I can get photos to load I'll show you what I have for sear engagement. We're not in dangerous country at all, just normal.

This is entirely a parts gun, no two parts from the same weapon, so it had an extremely long trigger travel with this combination. As you know when you start combining parts they sometimes have to be made to work together. Fitting the extractor is an example. Nothing wrong with fitting an extractor, it's part and parcel for the work at hand. This sear shortening was much the same. It was entirely too long creating excessive trigger travel, thus the need to shorten to a length giving function similar to the other guns here.

The separate task of rounding the sear is the bigger, more experimental issue. Although honestly, it's pretty simple machinery we're talking about here. There's no side to side wobble so the sear's not falling off the firing pin interface. No slamfire due to sharp blows, that's been proven with the wooden mallet.

Gnoahhhs concern with hardening and wear seems the most legit concern, one I had thought of and am mindfull of. But if you think about the wear created when two parts slide off one another, it would be perpendicular to the surfaces, "straight in" to one another. That type of wear would not create a more dangerous situation. If anything they would "mate" as they wear together, creating more bearing surface as they wear in. The exception to this would be where they disengage and all the firing pin spring tension slides off the point of the sear. That might be where the sear engagement could be left full width for wear resistance.

If this connection made cycles like a commercial sewing machine in a Thailand sweatshop I would worry more about *wear* and bearing surface. As it is, I'm not all lathered up about the number of trigger cycles a gun sees in it's lifetime.

Wish I could get my dang photos to work today...

So the metal I removed from the sear is on the actual mating surface with the rear of the firing pin, the "bulbous" interfacing piece of the firing pin remains unchanged. Now instead of the sear being about 1/8" wide contact area with the firing pin, it is 1/3 that. As mentioned, length of engagement was also reduced, not from "normal" to too short, but from too long to normal. I still have plenty of length of engagement. To include that information may muddy the waters for some, but don't let it, that's not really the topic.

So the sear is now sliding on 1/3 the surface area it was, as it is now three-sided rather than flat faced.

Side to side movement is controlled by the other end of the sear where the pin goes thru it. Remember me mentioning I had a damaged sear to start with? This is where it's damaged. This sear is actually missing a chunk of the metal that helps stabilize side to side movement. That's specifically why I chose to modify this one. It's got some built in "worse case scenario" with it's reduced side to side control, and yet it still works perfectly. An undamaged sear would be even better, so this seemed like a good choice to experiment with.

I think I get it. Thanks. Maybe the next thing to do is to assemble it into a beater and subject it to the beat test.

I did beat on it good and hard. I'm not done, when I get a minute I'll be back out there.

I mean the field beat test. Load it up and drag it out to the range with a pile of cheap ammo, given you can find any cheap stuff.

Still have some work to do before it's a shooter.

I had to drop my EG serial #5xxxxx about 10' when a tree stand step fell off leaving me hanging by one hand. I needed both hands free so I could wrap both arms around the tree and slid down to the next step. The safety slid off and the lever popped open but it didn't fire. I was about 15 or 16 at the time so that is one of several reasons I'm lucky to still be around. It might have shot me off of the tree if it had gone off or at least scared the s**t out of me. Literally !

Crappy photos-

So how does the trigger pull feel? My experience with post war 99s is that there is an amount of creep to get through as the two surfaces slide past each other. Sometimes there’s some stageyness also involved which I always figured had to do with less than perfect surfaces mating between the hammer and sear. Do you notice any less of these issues and/or is the pull any lighter? Pardon me if I missed this somewhere in your comments but I’m being lazy and trying to keep the topic going.

Before the mods, the trigger pull was very long, had "chatter" from machine marks on the sear, and had lots of hesitation and hangups.

It's shorter now, slick as snot no chatter but still very heavy. Completely happy with it One slip and gone. The weight is all I need to address at this point.

Not sure what you could do about weight short of clipping a coil on a spring. What do ya have in mind?

It would be interesting comparing your mod to another 99 that just had the mating surfaces polished.

That's all there is. Unless someone knows something about changing the composition of spring steel!

I'm with you so far. You might be onto something.

I wonder how much a fella can get away with in terms of clipping coils off the mainspring to lighten the pull without increasing lock time noticeably, and still get reliable ignition even in cold weather.