doublegunshop.com - home Forums General Discussion DIY Gunsmithing @ doublegunshop.com LC hammer spring clamp

The hammer or main spring on my grade 2 broke the other day. Heard a crunch and jingle and the right barrel failed to fire. I had several complete locks purchased some time ago via ebay or gunbroker (saw new and old springs at Numrich for 15.00) and swaped them using a needle nose vice grips. Not a complicated job for a novice like me but was told to be carefull with vise grips, gouging, and purchase a spring clamp. Hope this does not happen again but it is inevitable with 100 plus year old guns. Where can I purchase such a clamp or spring vise, is that nomenclature correct? LC locks are simple, engineered so to speak for quick and easy replacement. I am not a gunsmith, nor pretend or aspire so, and would not attempt anything more complicated that a simple swap, but I can see the need for proper tools for field expediency.

I have a spring clamp (cramp) that I bought many years ago for disassembling sidelocks. I thought that I could find one available at Track of the Wolf, or some similar supply house, but haven't been able to so far. I will take a pic of it this afternoon, and post it for you if nobody else does so by tonight.

Works very well.

SRH

Stan,

Thanks. Enjoy the holiday.

John

That's it, exactly.

SRH

If you search "Mainspring Vise" on EBay, there are several, less expensive ones available.

Regards
Ken

I always use a pair of long-nose vice grips with the jaws wrapped with black electrical tape to prevent scratching and gouging of the spring.

Steve

I do the same, but I also ground and then filed down the "teeth" of the jaws on a set of needle-nose Vise-Grip pliers- and used masking tape. Smith locks are way simpler to re-assemble than those found on British and European mfg. sidelock guns. Smith locks are a good design, for their time, but lack intercepting sears, and are a trap for the unwary--hammers must be cocked before you can safely remove and then re-assemble the forearm and barrels.

Smith devised a tool for disassembly and reassembly of the mainspring. it is not necessary to take the lock apart to do this, it is also used to cock the hammer when lock is off the action and cock the gun with the barrels and forend off. See Brophy page 195. I have one of the tools if anyone needs demensions.

Or even better- dimensions as to print. I have one, and it is well worth the $10.00 I paid for it years ago. Along with a 6 ft. tape ruler and a step choke gauge, it goes in my pocket when I go to area gun shows in the Winter months- sometimes find a dealer in distress, who let a proposed buyer remove the forearm and barrels from a Smith offered for sale, and then pulled the triggers and let down the hammers- great design, as the curved front section allows you to rotate the cocking rod front lug, against the opposite handed lug, and then, the other cocking rod. I have only seen one Smith gun that a careless or uninformed owner "boogered" by trying to re-assemble the barrels and forearm on a receiver with the hammers down-- Not a pretty sight.

Proper mainspring cramps

I can see why these are "proper" clamps since they spread the load out widely over the springs surface. I probably should've mentioned that when I use a pair of long-nosed vice grips padded with electrical tape, that I only depress the spring just enough to remove tension from the mechanism for removal.

Steve

Vice grips are a great way to break springs~

Making a spring holding fixture is a much better way to temporarily remove and replace springs. Maybe I'll take a pic of some of the dozen or so I've made?

They are simply a slotted bar of steel with the slot just big enough to slip over the compressed spring.

May be showing my ignorance but why are vice grips a great way to break spring?
Kirk

If you use them often enough, you will be telling me.
Looking at the spring vises and how they work will tell most of the reasons.

From my experience I feel that it is far, far harder to control the compression of the spring with something like pliers, of any type, which move the spring quickly with great leverage. Plus, if it does fly out of the pliers after removing it from the lock and flies across the room (or into your face), there is a great chance of breakage. With the proper spring cramp the thumbscrew slowly compresses the spring in a very controlled manner. I've done it both ways, and the greater control from a mainspring vise gives me much more confidence.

JMTCW, SRH

Sound advice, all. I shot the gun last weekend at Hausmann's. No problems. The directions in the Brophy book suggest removing the spring and sear as one. I can seen now why as the above spring compressors would not fit in between the sear and the spring. Thanks all. The knowledge and expereince on this forum never fail to amaze.

Spring holding fixtures made to fit individual springs while compressed. Slip over spring, remove, fix or work on whatever needed, then reinstall spring without ever removing fixture or releasing spring tension. Hugely helpful, pairs are for pared spring such as main or ejector springs. Old-time gunsmith tool. Two pics of same group.

An old "jury rig" way was to cock the piece, wrap a length of wire around the cocked spring( where there was room), twist it to hold, and then release the sear.
Mike

I thought I would add a couple of Brit clamping tools that are more universal than a dedicated main spring clamp. On the left of the picture are a couple of hand vices small and large, they did manufacture many sizes in between. The late Jack Rowe was a keen user of hand vices and I did see him recommend their use in one of his videos. On the right are what we call toolmakers clamps or sometimes known as steel fingers, these are made in sizes from a foot to an inch and they all have a smooth clamping area so leave no marks on your work. Toolmakers clamps are so shaped so they can be used in confined situations and you will be surprised how much clamping force can be given by one of these.
Unfortunately, these tools are considered old fashioned these days and not many tool merchants stock them here now. These are a lot more stable than trying to use pliers!!