Does this look unsafe to you?

[I'll Make Mine]

I've been watching a series of YouTube videos relative to "improving" the trigger in the Marlin 795. Apparently these come from the factory at around 5 1/2 lb (don't have a scale to try mine, and don't want to damage the firing pin dry firing it either -- the latter, at least, can be gotten around cheaply with #4 drywall anchors), and the various incremental changes (mostly replacing or rebending springs) let the video poster get his down to 2 1/2. I don't have any problems with most of them, safety wise (I don't know if I want to weaken the hammer spring, might make for light strikes, but that's not unsafe), except this one (http://www.youtube.com/watch?v=zqSoaQoF01w&list=SPEEE60871555F51D1&index=8).

I recall reading over and over that one shouldn't change the angle of the sear engagement -- which he doesn't, really, but he does significantly reduce the amount of engagement; that is, the distance the sear has to move to release the hammer is reduced by about half, if I'm seeing his wear marks correctly. He claims that slamming the butt of the rifle on the ground repeatedly didn't cause the rifle to fire, but after having the action out of my 795, I see that both the sear link and sear move forward to disengage the sear, not backward -- meaning that slamming the butt is the wrong method to test if the sear has been made unsafe; it's a bump on the front that might knock the sear off the hammer notch and fire the rifle, or possibly a hard bump on the bottom of the trigger guard (since most of the mass of the sear is forward of the pivot).

Am I misunderstanding the situation here? Is it actually safe to alter the sear the way he does? Is there an alternate, safer method (in addition to spring force reductions) to accomplish what he's after, reducing the trigger pull without spending a bunch of money on after market parts? I like the idea of a pull under three pounds -- that's close to the single-action pull of my Dan Wesson Model 15, which is very nice to fire -- but I don't want to compromise safety...

[zuke]

His pistol,his life,his problem.
You can try some of what he does,but if you feel it's un-safe don't do it,no one's forcing you to.

[kweidner]

most factory triggers have a bit too much engagement. However I would highly suggest you let a gunsmith handle this if you have never done trigger work. Those angles are very hard to keep. Your question suggests maybe you haven't done too many. Really easy to make a dangerous situation. I have done plenty of triggers on guns. I try to clean them up first. Polishing up a sear vs taking a bunch of metal off is two different things. Nothing wrong with trying if your confident but dont be afraid to buy a new hammer and sear if at end of job you have questions. Go slow check often. Make sure availability of parts before you start if this is your first go.

[I'll Make Mine]

The Marlin 795 is current manufacture, parts are easily available. If you watch his video, the way he's stoning doesn't touch the engagement surface in a way that could alter the angle, he just makes a bevel on the side toward the hammer that effectively blocks the sear out away from the hammer's sear notch -- reducing the engagement without changing the angle.

No, the only trigger work I've done to date was barely polishing the sear face on my Mosin Nagant (though I've done other repairs, including fabricating a replacement tip for a broken firing pin and replacement slide safety toggle in my Excam .380 and brazing up a broken interrupter in my Mosin's magazine). I have a stone so fine it'll barely even polish (I think it's what's called a claystone; I got it for final sharpening a straight razor, rather a long time ago), but even so I don't plan to polish the actual engagement tip of the sear; it looks very cleanly cut, as does the notch in the hammer.

I might point out that if I can't afford an after market trigger for this rifle, I certainly can't afford to pay a gunsmith to work on it -- but I'll leave it alone before I'll do anything that might make the trigger unsafe. If I decide to alter anything relative to the hammer and sear, I'm more inclined to stone the face of the hammer to reduce the depth of the notch without touching the engaging surfaces in any way.

[xd4584]

I don't see anything wrong with the way he modified his sear. I typically use aluminum foil tape in layers on the sear to reduce engagement until I find a nice break that won't go off when dropped or slammed on the ground. Then I measure and stone the sear down to that measurement.

[JIMinPHX]

Jerry K sells several good shop manuals on firearms. Proper sear adjustment & stoning is covered in detail in many of them. That is where I would recommend you start your search for reliable information. I don't trust youtube videos for stuff like that.

[I'll Make Mine]

Thanks, Jim -- right now, buying manuals is right out (at least if I want to be able to buy any .22 ammunition this month; I still need to get a sling and find out what rounds this rifle likes before going back to Appleseed in March, and time slips away). I'm asking this because I don't trust the YouTube video, either -- but I can't seem to get any information other than "don't trust YouTube videos" or "pay someone to do it."

So, xd, have you done this with a 795? Am I correct in thinking that slamming the butt isn't the correct force direction to test a modified sear in this rifle?

[JIMinPHX]

It's a test. It's probably not the only test you should perform if you want to be certain of safety.

[2152hq]

If the action is anything like the older Model 60/Model 90 and I suspect it is,,he took an awfull lot of the engagement surface of the sear edge and changed the angle of it. Perhaps all of the engagement of the sear to the hammer is now at a different angle.
It's not a new trick to bevel the near edge of a sear to reduce engagement surface with the hammer. It's been done on just about every slicked up 1911 target conversion ever done.
That gets a portion of the engagement surface right out of the way so it doesn't figure into the friction between the two surfaces. What's left is less surface and when that bevel you put on the sear gets out far enough the hammer pressure just cams the trigger out of the way at that point.
An extra step is to stake the sides of the sear engagement edge on the hammer so that the sear doesn't fall as deeply into the notch.
Now that the sear surface has been reduced for better pull,,why not reduce how far it drops into the original notch in the hammer. A tiny stake mark on either side of the hammer limits how far the sear drops into engagement.

Now you have the reduced engagement depth and engagement surface area...less friction,,less travel
All with out changing any factory sear engagement angles.

The sear angles should be 90 degrees to the center of the hammer & sear axis. More one way and you get extremely heavy pull. The other extremely light pull and even triggers/hammers that can cam themselves out of engagment w/o un-necessarily heavy trigger springs. That's just going around & around and accomplishing nothing.

This trigger pull job should have started out with checking the engagment & angles of the mechanism out of the rifle. The Marlin 90/60/whatever semiauto allows the action itself to be taken out and held in your hand. You can examine the engagement, see whats going on.
You can see if the engagement angles are correct. Or if the sear is camming the hammer back when it's releasing it..or if the hammer is creeping forward as the sear is being pulled,,,,both are bad. The former gives a terrible trigger pull. The latter is a safety issue and an unsafe light pull.
Disassemble, disengage the hammer spring and reeassemble. Try the engagment again and see what the let off feels like w/o the mainspring engaged. You have to develope a feel for these things, not just start stoning sear angles.

A test can be made to see what the hammer let off was by pressing on the sear bar with the action out of the rifle.
Again after only polishing the sear edges to remove roughness. (might be all that was needed)
These readings won't be trigger pull readings but you don't care at this point.
You can test for 'push-off' with the action out of the rifle. You can't with it assembled.
The 'bump the rifle on it's butt' is not a practical safety test.

2 1/2# pull is too light IMHO for a semi auto anything even a 22. I know many will take issue with it, but that's my opinion after working on these things for 40+ years including some at the Marlin factory.

I've seen more than a few 'accidents'

[I'll Make Mine]

Thanks, 2152, that answered much more of the question I had. I can confirm that the 795 action is very similar to the 60 -- so similar, in fact, that the two rifles appear to share a receiver casting (else why would there be a tube magazine hole under the barrel in a box magazine rifle?); the 795 has the magazine well in place of the cartridge elevator in the 60, which simplifies things enough to reduce the cost and let them sell the 795 for less than the 60.

Based on the entire video series, it looks like (assuming my action and springs are like his) one can get down to around three or three and a half pounds without touching the sear, and that's sufficient for me. I would be comfortable either shimming or staking to push the sear away from the hammer a hair (this can be easily undone, also), and might well stone the hammer to reduce the depth of the notch only (easier than staking, but not reversible, so it would have to be taken very slowly); I'm inclined to leave the engagement surfaces completely alone unless there's a visible burr. I'm curious, a little, how reduced engagement helps trigger pull, since I recall my college statics courses teaching that steel on steel should have the same coefficient of friction (i.e. same normal force yields same friction force) regardless of contact area, but I won't argue; it's been done successfully for too many decades to be a myth.

I definitely prefer the idea of comparative testing of the sear disengagement force with the action out of the rifle -- no banging up the firing pin, but I can still get some kind of quantitative comparison as I make changes.

[2152hq]

"...I'm curious, a little, how reduced engagement helps trigger pull, since I recall my college statics courses teaching that steel on steel should have the same coefficient of friction (i.e. same normal force yields same friction force) regardless of contact area, but I won't argue; it's been done successfully for too many decades to be a myth."

I don't know about the physics of it, there's alot at work in a simple trigger. The hammer spring weight,,the sear return spring weight, the angle of both the sear edge and the hammer notch to their axis,,and correspondingly to each other. Then you add the sear engagement depth, it's edge finish, leverage available from the trigger itself, ect and you can see all kinds of variables that can effect trigger pull.

Reduced engagement helps reduce trigger creep felt by the shooter. It just doesn't have to move as far to release the hammer.
But the other factors like sear angle & hammer notch relative to their axis has to be correct first or it means nothing. It actually could decrease the safety of the trigger if the angles are negative to the axis and the hammer is camming the sear away on it's own w/o any help from the shooter to begin with.
The engagement surfaces are not a perfect mirror polish. They are a series of grooves when you look at them under magnification. The grooves are the result of the grit (stoning, polishing, grinding, ect) that's done to form the edge surface.

How fine/shallow those grooves are is a result of how fine of a grit the 'smith uses in the process of the job. If you try and go for that glass smooth surface, most will end up rounding one or both of the surfaces ruining any chance of a smooth pull and clean break.
The longer you work over the area, the greater chance you have of not leaving it flat and square. That's true in any polishing
The coarser grits will interlock the parts as the microscopic ridges on each sit down in between each other like teeth. Pulling the surfaces accross each other under spring tension results in a heavy and 'gritty' trigger pull with a lot of creep.,,but still a safe one as the angles are still right.
You have the right angles for safety,,you don't want to loose those.

You want to avoid over working the surfaces looking to get a glass perfect surface on each thinking they'll slide like ball bearings.
Doing so will usually lead to rounding them over & then you've done nothing but given it a lighter pull by changing the angles to a less than safe position. You have to find a way to get the lighter pull but keep the safety of the mechanism in tact.

So what to do...In addition to the beveled sear edge and the staked sear notch, you can also do one more thing..and you may have already done this w/o realizing it.
When you touch up the factory angled surfaces of the sear and the hammer notch,,polish them in opposite directions.
No changing angles (if you're sure they are OK to begin with).
Just smoothing out any obvious burrs or damage to the surfaces.
The hammer by it's shape usually has to be touched up cross wise to the part on it's notch. That's fine. Do that, then with the same grit do the sear edge and do that length wise to the part.
You'll have those same microscopic grit lines in each. But being at 90degrees to each other they will glide over the top of each other instead of chattering & grabbing as the surfaces move.

There's alot that can be done in trigger work before you get to the point of changing other wise safe sear angles.
Even the fit of the part on it's axis pin should be looked at and wether the 2 parts are meeting squarely or not to begin with.

Go slow, look it over carefully, make it safe,

[I'll Make Mine]

Thanks again, 2152. I see what you're driving at -- glass smooth isn't desirable, and getting there introduces other undesirable factors (like rounding off what should be a cleanly breaking edge). I think that might explain how reducing engagement reduces pull, too -- fewer of those interlocking ridges, and/or the process of adjusting results in crossed, rather than interlocking ridges.

With the tools I have, I'm not confident of being able to do anything to the actual sear face without changing the angle, so I'm not going to touch that. Beyond that, it'll be a couple days before I have time to do anything at all, but safety is first -- hence asking before charging in.

[leftiye]

Remove your action from the stock. Remove the scope. Put a piece of 2x4 or 2x6 on a concrete floor and hit the cocked action on that (it won't mar the blueing). If you think the direction of the hit matters, test it by hitting the muzzle on the block of softwood. This is more impact than you'll get by throwing the rifle against almost anything.

[I'll Make Mine]

Remove your action from the stock. Remove the scope. Put a piece of 2x4 or 2x6 on a concrete floor and hit the cocked action on that (it won't mar the blueing). If you think the direction of the hit matters, test it by hitting the muzzle on the block of softwood. This is more impact than you'll get by throwing the rifle against almost anything.

Have you had the action out of the receiver in a 795 or 60? The receiver in these is a fairly thin shell of die-cast metal (aluminum, zinc, or an alloy, hard to be sure, but zinc and its alloys are cheaper to cast than aluminum due to lower melting point). Banging that on anything remotely solid strikes me as a bad idea; in addition, that part isn't blued, it's painted, and I'd bet this will mar the paint at the point of impact even if it doesn't just break the shell.

[leftiye]

What can I say? Should still work on the muzzle? Nope, never saw either one.

[2152hq]

The receivers were aluminum alloy,,at least in the early 70's time period. Alcoa used to supply the castings at that time IIRC.
They were plenty tough for the job, but could be damaged with the blow of a nylon head bench mallet.
Bouncing them onto a hard surface will damage them,,they're thin at the back end.

We used to 'dismantle' the recv'r from the bbl on a rifle being stripped for parts by a couple of healthy wacks with a hammer to crack the recv'r right off of the bbl shank.
Removing a receiver from a bbl shank can be done easily after punching out the cross pin and carefully tapping the recev'r back off the bbl. Get too rough with it and it will crack on you though.

At one time they still wanted us to save the parts on pre-68 unser#'d rifles that came in for warrantee work in post '68 times.
Since the rifles were mearly replaced with a new one and sent back to the stores that had sent them in (Pennys, Cosco, K-Mart, ect), they were called turn-arounds.
At first were were assigning and stamping a ser# onto the previously un#'d receivers and rebuilding them. That took too long for the bean counters.
Then they had us simply strip them for parts and destroy the receivers (hammer method). Then still later even that wasn't 'efficient' so other than taking the bbled action from the stock and saving the wood to be refinished and used again,,the entire barreled action was scraped.
Same with the bolt action 22's,, Model 80's ect.

Best to check sear engagement with what we called the 'action' out of the rifle. That's just the guts of the rifle,,the two side plates with the hammer, sear, feed throat lifter, buffer and springs in between them.
Not much can be learned and nothing examined with the rifle assembled,,unless x-ray vision is something you have available to you.

[I'll Make Mine]

We used to 'dismantle' the recv'r from the bbl on a rifle being stripped for parts by a couple of healthy wacks with a hammer to crack the recv'r right off of the bbl shank.
Removing a receiver from a bbl shank can be done easily after punching out the cross pin and carefully tapping the recev'r back off the bbl. Get too rough with it and it will crack on you though.

This reminds me of some of the things I have to do on the job -- there are assemblies in some power tools that simply can't be taken apart without destroying something. Usually, you can arrange for that to be a $5 seal instead of the $80 housing, but not always.

Given what the cost to manufacture must be, even today, to sell a rifle for $150 out the door, I can see the bean counters getting upset if there's any labor expended that can be avoided; if you spent twenty minutes (even at technician wages, never mind gunsmith rates) stripping a rifle, you'd charge off almost enough labor to cover replacement. The dollar figures were lower in the early '70s (the 60 sold for, what, $60 back then?), but relative costs were pretty much what they are now. Throw in any time at all spent troubleshooting and actually repairing something, and scrapping an entire barreled action without examination was/is a good business decision.

Whether the receiver casting is still aluminum, or has been changed to a zinc alloy, doesn't really even matter at this point; as I noted, it costs less to cast zinc or Zamack because of the lower temperature, but those alloys are generally more brittle than casting grades of aluminum. Given this receiver shell is a low stress part, it wouldn't surprise me at all to find it's now done in zinc, but unless I drop the rifle on concrete or take a hammer to the receiver (or put too big a wrench on the screws when mounting something on the dovetail), zinc should do the job just fine.

[shadygrady]

well when you break all that zinc up send it to me for lead

[I'll Make Mine]

Well, after viewing the YouTube videos and examining my 795 action, I was pretty sure I could do all the alterations other than the (potentially unsafe) stoning of the sear without splitting the action plates -- and I was right. The trigger return spring was easy -- push out the forward pivot pin (only -- that way the trigger is never loose), bend the shutter spring out of a 3.5" diskette to match the original, and put it back together, took five minutes or so after removing the trigger guard assembly. I had correctly estimated that I could rebend the sear spring without removing it from the action; just disengage the long leg from the grooved pin on the magazine disconnect, squeeze the straight and bent legs together (with the coil still on the post, captive in the action) until they're at 90º resting position, and then reset the spring in its original position. The next step I haven't done yet, but the video actually demonstrates removing the hammer spring for clipping with the action still together, and if I decide I need this step, I'll do it that way (though I'll probably use my Dremel to cut the spring so I get a flat end first try if I do cut it). I found I could actually hold the trigger guard assembly and action together well enough to fire the action via the trigger, which gave me a pretty good idea of how the pull was changing despite not having a trigger scale available; my "calibrated fingertip" tells me I reduced the original pull by about a third, which is fine for now.

It seems as though the sear engagement on my rifle is pretty narrow already (not much over 1/32", possibly .050" at most), so I'm not going to touch those parts in any way until I've got at least a few hundred shots through the rifle, and likewise I won't touch the hammer spring without firing a few boxes first. Also, unlike the YouTube poster, I rather like having a magazine safety; it lets me keep a round in the chamber and a full ten in the detached magazine with confidence the rifle can't fire.