As many of you already know, and some of you who are buying your first "box of parts" will find, the trigger guards that we start with are usually rough sand castings.
Many of these are copies of original trigger guards and are cast in brass, German silver and steel but they all share a common problem. They are much thicker than the originals were.
The primary reason for this is twofold.
First, the maker knows that the surfaces will be very rough, usually with a "split line" showing down the center of them where the cope and drag of the sand casting equipment is split, so he adds extra material to allow you to file off the rough surface and the split line mark.
Second, metal shrinks as it cools from its molten condition to the finished casting.
This means he has to cast the part slightly larger and thicker than the original to end up with a casting that is not too thin.
As many of us want to get things done as rapidly as possible we tend to file the surfaces until all traces of the original rough sand cast surfaces are removed. Then we set to work sanding and polishing until we get a nice shiny part ready to install.
The problem with this goes back to the fact that these things are cast too thick and just removing the rough surfaces isn't enough to bring them down to the thin elegant parts they are supposed to replicate.
I just measured a few rough trigger guard castings that I have on hand and I find that the average thickness of the bow area is about .185 thick.
After studying some photos in RCA (Rifles of Colonial America ) of the trigger guard on the rifle I'm using as a model for my latest work I realized that the trigger guard needed to be about .120 thick in the bow area. Anything thicker would detract from the slim features of the original gun.
This resulted in the need to remove over 1/32 of an inch from both the inside and outside surfaces which is quite a bit of filing.
I suggest that if you can, find some good photos of the rifle you are trying to duplicate or of rifles that were made in the time period you are trying to make.
Don't be afraid of making your trigger guard too thin (within reason). Your finished rifle will look all the better for your efforts.
Many of these are copies of original trigger guards and are cast in brass, German silver and steel but they all share a common problem. They are much thicker than the originals were.
The primary reason for this is twofold.
First, the maker knows that the surfaces will be very rough, usually with a "split line" showing down the center of them where the cope and drag of the sand casting equipment is split, so he adds extra material to allow you to file off the rough surface and the split line mark.
Second, metal shrinks as it cools from its molten condition to the finished casting.
This means he has to cast the part slightly larger and thicker than the original to end up with a casting that is not too thin.
As many of us want to get things done as rapidly as possible we tend to file the surfaces until all traces of the original rough sand cast surfaces are removed. Then we set to work sanding and polishing until we get a nice shiny part ready to install.
The problem with this goes back to the fact that these things are cast too thick and just removing the rough surfaces isn't enough to bring them down to the thin elegant parts they are supposed to replicate.
I just measured a few rough trigger guard castings that I have on hand and I find that the average thickness of the bow area is about .185 thick.
After studying some photos in RCA (Rifles of Colonial America ) of the trigger guard on the rifle I'm using as a model for my latest work I realized that the trigger guard needed to be about .120 thick in the bow area. Anything thicker would detract from the slim features of the original gun.
This resulted in the need to remove over 1/32 of an inch from both the inside and outside surfaces which is quite a bit of filing.
I suggest that if you can, find some good photos of the rifle you are trying to duplicate or of rifles that were made in the time period you are trying to make.
Don't be afraid of making your trigger guard too thin (within reason). Your finished rifle will look all the better for your efforts.