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

Considering how hard it is to compress that dadgum firing pin spring by hand and get a pin thru the firing pin to hold it I believe I could safely take a coil or two and try it.

For me a better comparison would be a before/after of the same weapon. A different weapon introduces an entirely new set of variables.

Roy,
sent you a pm with a link to a post on another forum ref trigger pull. If link does not work, pm me your email and I'll send a pdf print of it.

Gary might. He’s the science guru on stuff like this. You two should team up on 99 “method and theory.”!

You could do that but it might get a bit tedious pulling and replacing parts for an A B comparison. I think it might be good enough polishing the trigger on one of your other 99s for purposes of comparison, unless you’ve seen a lot of variability in how 99s were manufactured.

Variability in the parts is the fox in the hen house! These rifles were made in an era where parts interchangeability was just a dream.

It takes zero time to drop the bolt, remove the cross bolt that holds the sear and drop another one in. It would be a good experiment. I'll work on that when I get time.

Well then very cool!

Did you perchance measure trigger pull weight before starting the experiment? If you get around to measuring pull weight how about measuring it when dry and also well lubed.

I have wondered about the junction of the sear and trigger. Some triggers have an oval hole in which the sear pin rides, others are a simple open ended slot. Either way it's a basic camming action that happens in there when you pull the trigger. Polishing those surfaces might reduce pull weight a skinch too (but obviously do nothing about creep). I think by the very nature of the Savage system, creep is inevitable, and a necessity for safety. Like you said (I think) the trick is to reduce creep to the point where it isn't so annoying yet still plenty safe.*

Getting back to beveling the sear surface. I wonder if it'll wear more rapidly now that there's only 30% of the original surface bearing on the hammer. What am I saying, of course it'll wear more rapidly. The question is how fast will it wear and does that really matter? Dunno.

You have me sitting here studying my own naked receiver (1913 1899A) and it occurred to me to bless Arthur Savage for making the whole trigger/sear/hammer system a compound lever design. Can you imagine the gorilla fingers you would need to squeeze off a shot if the trigger was holding back the hammer all by its lonesome?

* Note: I'm not advocating shortening sear engagement. What Roy is doing is skating out close to thin ice and turning back before it's too late. He knows what he's doing and is savvy enough to recognize failure and replace parts before an innocent gets hurt. The Bubbas of this world don't always get it.

X amount of spring force is now applied to 33% of the area as before, so it's bound to wear faster, but enough to notice?

Consider the number of cycles a mechanism like an internal combustion engine does, with the heat generated, the sheer number of rotations, and the force applied to the moving parts. Look how long it can run under those loads before wearing out. I think 20, 200 or even 2000 shots a year on the old 1899 trigger will be workable.

Gary, did I hear you say that the firing system has a camming action that increases the mechanical advantage of the trigger? Geez I hope that question made sense. If so, would there be any way to modify that mechanical advantage, say boost it or make it adjustable. Crap, now I’m going to have to pull a stock!

Also, I guess if wear was an issue you could have the parts hard chromed. Would hard chroming, for lack of a better word, increase the slickness of the sear trigger action? I know my father used to recommend hard chroming John Deere drive shafts as an economical alternative to buying a factory new shaft. We’re talking the big four-wheel drive units from back in the 70s.

No, Jeff, not exactly. The camming action comes from the trigger moving through an arc while pulling the sear down via the pin in the sear. If you watch it while it goes you can see the pin travels (rubs) for about 1/16" on the slot cut in the leading end of the trigger. "Camming" may not be the best term but I can't think of anything else to call it.

Roy, as for wear, I agree it's probably a non-issue. But, if you look at it in terms of 30, 40 50 years down the road then it might. This 106 year old action has been cycled 137,463 times (I counted ), or, well, a helluva lot I'm sure. It shows definite wear on the sear interfaces. Again,a non-issue at this point in time I'm sure. If I were to use this action for a build I would probably only stone the sear interface and call it a day.

I hope to someday wear out a single rifle part. LOL. I'll be having a good time!

Maybe we should all get together with one gun and make it our goal to not stop shooting until we’ve worn out “a single rifle part.” You know, bucket list stuff.

Here's my bit of troubling experience with sear engagement, which might be, ** a risk for Roy's sear modification***; I had an 1899, I don't know the serial number but it had a round-back bolt and a hammer/sear style like Roy's. I replaced the butt stock and rushed off to the range.. I had round #5 discharge while putting the bolt into battery. I couldn't get it to happen on the bench with the butt stock off.

I thought the hammer or sear might be hanging up on the rough wood surface of my rushed inletting work, so I rasped back the inside of the side panels. It must have been dragging somewhere because lever movement got smoother and I could not recreate false hammer trip. Back to the range, and it happened again on round #20.

Turns out that there was some slop (damage? wear?) in the hammer pin, allowing it to rotate on the firing pin a couple degrees. The sear and it's pivot pin also had some slop (wear? or mis-matched parts?), that allowed it to shift off it's left/right vertical. ***The sear was actually slipping off the SIDE of the hammer*** as it cycled into battery.

The solution was replacing the sear and sear pivot pin, removing the barrel and making that receiver into a parts donor paperweight, an someday a lamp.

I believe there is side play in all the hammer,firing pin combinations. I have noticed it in all the savage rifles i have worked on. i would be leary of thinning either the trigger sear or the hammer block very much. not saying it cant be done a bit and improve trigger pull, just use caution.im sure the triggersear would take along time to wear even being thinned. Don

I will check side to side play and see if I can force the sear to slip off the firing pin. Thanks for the input!

I’m not certain side play is going to be an issue with Roy’s mod. As I understand it, he only reduced the amount of interface on one side thus allowing that side of the assembly room for lateral movement against the opposing and factory original sized side. The reduced face may wiggle back and forth but, unless he runs into JeffGs situation, it shouldn’t move any further than the width of the opposing face.

But I have to add that if Roy does run into JeffGs issue, then he’ll get there faster with his modification than he would have if the parts were left alone. All this does make you wonder why Savage in the first place chose the dimensions he did for these parts.

Just checked the side to side play by prying with a screwdriver to try to get parts to disengage either way. Nope.

I thought of the side play thing yesterday because I thought I remembered it in the 1914-vintage action I resurrected a few years ago. Last evening while messing with the current "orphan" (visual aid for following along with Roy's treatise) I couldn't get the parts to move laterally, so I disassembled one of the "good" guns to see if it had that trait, and then the aforementioned 1914 H. No on all accounts. Sorry, I'm not going down the line and checking all of my guys for this!

I can see where it could be an issue though. But, I submit that a savvy Tinkerbelle would be attuned to such situations and either correct the issue or cease and desist with tuning the sear on that particular rifle. Such a problem would be an indicator of other possibly more serious issues than a merely rough trigger pull.

If there were any issues of side movement I’d check to see if it tended to be more in one direction than the other. If so, then Roy’s mid could be offset to the opposing side of the movement. Not that I’m trying to take sides on anything here 🤪