Material for custom Marlin 336 lever?

[FrankenMauser]

I am working on a project that requires a straight-grip conversion on a Marlin 336 that is currently pistol-grip style.

I don't want to go the easy route this time and pay $65+ for a M444T lever, or re-time the action to work with a modified 1895 lever; so I've committed to modifying the existing pistol grip lever (saves me from additional action work, too ).

Since I'm already modifying and need to add material, I figure I might as well go full custom with the part.
I plan to rust blue the rifle when finished. I've considered color case-hardening for the lever and some other accoutrements, but the official plan is rust-bluing.

Which brings me to the question(s):

What type of flat stock would you recommend?
Hot-rolled A-36? Cold rolled 1018? Something harder?
Most tool steels seem to be too high in nickel and require more post-weld heat treating, correct?

Is annealing or heat-treating really necessary afterward?
I would like to get away with using heat sinks and heat control paste on everything from the trigger guard forward.

Would ER70S-6 be appropriate fill material?
(Mild steel alloy -- 0.85% silicon, 1.5% manganese, 0.2% copper, only traces of other common alloy elements.)

 

[dakota.potts]

I'm not clear on which part it is that you're making. If it's the finger lever, I hope you're a pretty talented machinist. Lots of very important cam surfaces on that lever.

My inclination would be towards something like a 4140. Without too much experience with 1018 it seems to do alright, but my experience with hot rolled is that it is very gummy when machining and tends to roll up rather than cut.

 

[Scorch]

I would say use 4140, since that is the original material. And you shouldn't need to heat treat unless you get it hot from the trigger guard bow forward. But I would anyway.

 

[Gunplummer]

I really don't know what material Marlin uses for the levers. I can honestly say I never saw a broken Marlin lever. Savage always used 1018 (Or something really close). I guess 4140 would be fine. 1018 would be easier to repair with weld if you screw up a little.It is easy to case with a torch and Kasenite. I used to build up worn bumper cams on 99's all the time. At one time I had a block milled out to heat and put levers back to original configuration. People want to seem to bend the straight levers using only a torch. In the end it will be your decision. Try it with some junk first.

 

[BoogieMan]

1018 would be my last choice for anything. The only time we use it is if the customer specifically calls it out or other materials are not available in the size/profile. As some one else suggested 4140 would likely hold up well. You may also want to consider 1045, 1215, 4130. All are superior to 1018 for machining and strength. All are also available in flat stock.

 

[45_auto]

so I've committed to modifying the existing pistol grip lever

If you're just modifying the shape of the loop of the existing lever than any crap steel you have lying around will work fine. You can't put enough load on it to bother it. Polishing a small piece and checking if it will match the original steel in bluing would be a good idea.

Just don't heat up anything forward of the finger loop.

Is annealing or heat-treating really necessary afterward?
I would like to get away with using heat sinks and heat control paste on everything from the trigger guard forward.

It's much easier to control the heat than to re-heat treat correctly for most amateurs. What's so hard about sticking the working surfaces in a bucket of wet sand while you're welding? Use a TIG welder if possible where you can really focus the heat.

There is no need to heat treat the new finger loop.

If you get the working surfaces hot enough to anneal them, your lever is junk unless you re-heat treat it.

 

[Wyosmith]

If I were doing that project I think I'd use 12L14 and case harden.

Just as a side note, that's how C&H reloading Dies are made. They are cased, and they come out at about 66 Rockwell surface hardness. 12L14 is very stable through the heat and quench. Anyone that has used C&H dies knows that they are high quality and dimensionally correct.

 

[FrankenMauser]

Thanks for the replies.

I guess I could have been a little more clear, but it looks like most of you understood what I was after.
It's just the finger loop that I intend to modify. Everything forward of the trigger safety contact pad (including the trigger bow) is to remain untouched. I may recontour the lever just forward of the trigger bow later on, to get more of the 'early style' shape, but there would be no heat involved.

I still appreciate the suggestion, but was already planning on running some bluing tests on the metals before any modification happens.


The finger lever in question, with some sketches that didn't quite make the cut:

All shaping will be done by hand, or, at the very most, with some careful work with a grinder and a disc/belt combination sander.


I'll look around to see what what flat stock I can find in the suggested alloys, and probably end up back here with a few more questions.
I know I can get 4140, but standard sizes are larger than I'd like. If I've ever worked with 1018, it was just scrap metal that I had lying around, and I didn't know it at the time. And, not surprisingly, I can't find a local supplier with any 1018 flat bar on hand that's smaller than 1/2 x 1". (The local steel supply situation is pretty miserable here.)
So, nearly anything that seems to be acceptable, let alone recommended, would have to be ordered.

 

[Dixie Gunsmithing]

You can use or add about any carbon steel for the lever itself, but not the part in front of the trigger guard, the cam. Like was aforementioned, cut off what you don't want, pre-bend or cut what you want to add, then stick the cam down into wet sand or water, and weld the new hoop on, using the smallest amount of heat possible. To be honest, one could weld those two welds with a small stick, and the heat not travel enough to the cam, if it were held in a vise. However, a Tig weld would be best for the heat input.

Some carbon steels will be hard to get in hot rolled plate, and will probably be available only is cold rolled plate. I'd look at 1040 or 1045, as if you ever wanted to harden and temper it, you could.

If you know someone with a burning machine, with the photocell eye option, you can take them a full scale, black inked drawing, and they can lay that on the pattern table and burn it out quickly. Many smaller steel fabricators have these machines.

 

[FrankenMauser]

Yea, there will be no messing with the carrier cam, locking bolt hook, or the bolt actuating cam/lever. I'm not going to touch it, and I'm going to do everything possible to keep heat out of the area.
Some of the factory rifles already have enough issues with the cam on the lever and the ramp surface of the carrier, in particular. Reshaping the cam is tedious and annoying. Been there. Done that. Want to avoid it, since this action is timed beautifully.

While running some errands and looking for local alternatives for flat stock, I was thinking about getting a quote to have the finger loop cut on a water jet or laser table. I have little experience there, so I have no idea what the cost would be, or how common tables are that can burn 3/8"+ material.
Honestly, I had, at least temporarily, forgotten about that idea, until I read your post.

I'd rather be able to say I did it myself, but having the basic shape pre-cut would definitely simplify things - especially with one fairly tight corner on the design I anticipate using.
There's a steel supplier about 45 minutes north of me that advertises their burn table in the yellow pages. Perhaps I should give them a call.


I managed to find some hot rolled / 'cold finished' 1018 in a local hardware store. It feels like it would be stiff enough for normal use, but wouldn't stand up to any abuse. Regardless, I would need to split a 3/8" or 7/16" strip out of the 1" wide flat, if I used what's in stock. And, of course, it would have to polish and blue reasonably well. I'm not really feeling the magic there, but it's available as a backup plan.

 

[FrankenMauser]

Thanks for the help, guys. And I'll be bookmarking this discussion for future reference.

But after looking at available materials and welding rod (and the cost of some of them with minimum orders! ), factoring in my skill, consulting family and neighbors that sometimes have access to TIG welders (but not right now ), and returning to a quote from Jamie at Mule Loops, I've decided to let a 'professional' do the job.

I made a 1:1 template and am currently waiting on the CA glue to dry on a simple jig that I put together to help ensure the lever/tang alignment comes out as close as possible to what I want.


It's going to be a little-finger-twisting design, if not used properly. But it's what I want.
(Pins are taped, in preparation for an epoxy clear-coat.)

The jig works as follows:
Drop the lever over the pivot pin (right). (O-1 drill rod ground to 0.002" under hole diameter).
Swing it up until the trigger safety contact pad hits the second pin (left).
See how it's looking.
That's it.

 

[Gunplummer]

Now I am curious. If you get a small piece of the original lever left over, heat it up cherry red and throw it in oil. See if it is for sure high carbon steel. The only way I ever got a good match when bluing welded 4140 was to gas weld with a 4140 rod.

 

[FrankenMauser]

If I get any scraps, I'll try it out, Gunplummer.
I really don't know what the factory levers were made from, and hardness/hardening seems to depend on the year of manufacture. So, there's not much to go on, there.

I've worked on five to seven 336/444/1895 levers, and run a file across a few more as a quick hardness check.
Some of them are butter-soft.
Some are hard as a rock, through-and-through.
Others seem more like they were case-hardened. (Break through the hard shell, and it turns to butter.)
I don't know....

 

[T. O'Heir]

Modifying the existing pistol grip lever would be more black smithy work than machinist. Heat, flattening and bending, assorted. Shouldn't need heat treating at all. Just re-shaping. The lever doesn't do anything but open and close the action. No stress than would require hardening.
You might get a fair bit of thinning of the steel of the loop itself. Don't think that'd make much difference either though.

 

[HiBC]

It looks to me like you can straighten and reshape nearly all of the existing lever.
Use nearly all of the loop in place.BTW,I suggest getting a lever from Numrich or ? to work with.Save your original lever.

The only place you appear you need some new steel would be for your unique take on the tail end of the loop. Do your cut and weld back there as far as possible.

 

[FrankenMauser]

Jamie (Mule Loops) works with flat bar, primarily. My bet is that he will form the new finger loop according to the drawing, cut it to length, chop the pistol grip loop off of the lever, fine-tune the jointing areas, and mate the two halves.

 

[hooligan1]

HiBC stole my idea, you can cut and reuse some or all of that loop FrankenMauser just by flipping it around, but still some new metal must be added....cool idea though, can't wait to see the finished product man.

 

[FrankenMauser]

Old thread.

Got lost while looking for something in my "started threads" history, and ended up here.

Figured at least a couple of you might be interested in what Jamie sent back to me.

It's 99% of what I wanted and fits the 'theme' of the rifle very well.
Just, for god's sake, don't get your little finger caught in the 'extension' while shucking shells.

(His photo, before shipping.)

 

[michaeldarnold]

I'd like to see the whole gun.

 

[FrankenMauser]

Working on it.

Many delays.
Medical issues. Illnesses. Flooded basement. Major (unplanned) remodel. And on, and on...

It's priority #1 on the bench, but not priority #1 in my life.

Working on it...