Where to get custom torsion springs?

[Jason]

The hammer spring broke on one of my Marlin 57s and I put off buying it from Numrich until I had time to make an inventory of other parts to order with it. Now that I have that, the hammer spring is out of stock. I did find them at Ponderosa Parts, but he wants $15+ each plus shipping for them and only takes checks or money orders mailed to him for payment as opposed to $6.45 from Numrich who takes online orders with a credit card. I also have a Marlin 57M that a hammer spring that's obviously not getting the job done well anymore, so I'd be buying at least two plus shipping. Then I would have to wait on a check to get there and be held 10 days before he ships or go to the post office to get a money order and then wait on it to get there and him to ship the springs to me. After either of those scenarios, I'd have 50-year-old springs that I have no idea how much use they got. It occurred to me that it would be a lot better idea to buy new manufacture piano wire springs, which would be both newer technology and not have an unknown 50-year history. It turns out that buying new ones is easier said than done, though. Those springs are basically just torsion springs with a bit of a tweak on each leg that I could put into the springs myself, but I'm having a surprisingly hard time finding just the base torsion springs. Hopefully someone here can help me find a source for them.

They are made of wire that's 0.052" diameter and there are just short of eight right hand twist coils, with the leg positions at about 280 degrees (i.e.- legs in free position are about 80 degrees apart on the same side of the coil). The body of the coil is about .452" long, but I could probably fit up to around 0.50" in there if necessary, as there is some room between the sideplates, but I wouldn't want to put pressure that would cause the spring to drag on the sideplate. The outside diameter of the coil is about 0.320" and the inside diameter is about 0.216" or so, and I could probably fit up to 0.420" or so for outside diameter in the space the spring sits in. The pin that it sits around is tiny compared to that inside diameter, so it could be smaller than that but I don't think that's likely based on what I've seen so far. Each leg is about 1.67" long. There's enough clearance in the groove of the hammer to fit at least 0.055" or thicker wire. All of that means that I need a right-hand twist torsion spring made of 0.046 to 0.055" wire with max coil length of 0.50", max outside diameter of 0.420", free position of legs anywhere from 270 to 320 degrees (possibly even 360 for music wire) and legs at least 1.67" long. I'd prefer music wire over chrome silicon or stainless for this application, but would probably take what I could get. I'd also prefer for the legs to be a bit longer to make it easier to put little curve on the end of one of them, of which I could cut the excess off later.

Now.. with all that that (possibly unnecessary to answer the question) said, does anyone know of a place I can get a fairly specific torsion spring like that, hopefully without having to pay the labor cost of custom making them? Surely there's some other application in the world for such a spring so someone already makes them. If I do have to go custom, where would be a good place to go? I wouldn't actually mind paying more for new manufacturer torsion springs than I'd have to pay for the original Marlin springs from Poderosa.

[dan222]

howdy,
i think you might find what you need at brownells, go to their website or call them. good luck.....dan

[Jason]

Thanks, Dan. I am planning on calling them tomorrow, but I'm not expecting them to have a spring that I can use. I'm hoping they can tell me where I can get one, though.

[Jason]

After many searches and phone calls, I finally just ordered a spool of .055" music wire and am going to attempt to make my own springs. The jig looks easy enough to make, the material is cheap, and I get to do something that I haven't done before. Worst case, I lose a bit of time and $6 of materials. I'll have to wait until my wife is out of the house to do the stress relief on the music wire in the oven, though. I might just pick up a cheap toaster oven for stuff like this and other similar tasks. Powder coating might be next.

[Jason]

Finally got around to trying to make these springs tonight. It took a few tries to get the hang of it, but it wasn't too bad. I probably went through 10-15 feet of the 124-foot spool that cost a whopping $6 before I got anything resembling a nice-looking spring, and about three more tries before I got nice tight coils with legs the right length with the correct shapes on the ends. I tested them a couple times for function in the rifle and they worked a lot better than the originals. They have one coil less and slightly larger diameter music wire, so I'm setting them to have just a bit less deflection than the originals when in use. I've got a couple in the oven for stress relief now and hope to test them with live fire in the rifles tomorrow or Monday.

Weak hammer springs have been an Achilles heel for the Marlin 57 design, as they don't have the ability to drop the hammer without dry firing. Dry firing tends to break firing pins in them in additional to peening breeches on them, so many owners left them cocked and the hammer springs suffered for it. From initial indications, I would much rather have these new ones that I made in the rifles for the next matches. I'm quite a fan of consistent ignition.