flytrout said:
Casting has been around since 3000BC. Good thing our (or at less mine) forefathers did sand casting of firearms parts or we would not have the freedom today or the firearms from the past. I have been doing green sand casting for years and prefer to take the pride of making my parts as they where made back then. As far as I know investment casting was not back in the 1500's. But some cannot or have the time to do this and I can understand that and respect that. Yes in retirement gives me the two days needed to cast and fit my parts. I only order parts that I have no molds for. I have casted gun parts to mini jet engine parts. I understand that I have a Aerospace degree and a lot of people don't have the technical know how. It is great that TRS offers these parts, I just wish they could keep up with demand.
Of course sand casting has been around for over 3,000 years but keep in mind that investment casting has been around for at least that long as well. Examples of investment casting are known from ancient Egypt and the Mayan culture and others in Asia as well as Africa. The advantage to investment casting? They are as follows:
1 - Dimensional accuracy is far higher than in sand casting.
2 - Detail that can
not be achieved with sand casting. More intricate patterns can be cast with investment casting than sand casting.
3 - Smoother surfaces, you don't have to spend as much time in finish work especially with the detailed castings possible from the investment casting process.
4 - Any metal or alloy of those metals can be investment cast with the above advantages.
Are there disadvantages to wax casting? Of course, it is more expensive and requires training not available in a small shop and sand casting is much easier to set up and use but that is about it. Sand casting is fine for gun furniture such as butt plates, butt caps and trigger guards.
However, sand casting is
not acceptable for cast parts that are used under heavy stress. As a general rule, it is not now nor has it ever been acceptable for stressed parts like tumblers, sears, springs or gun breeches - far to many flaws - often hidden - are found in sand casting to guarantee effectiveness with these parts. The grain structure of sand cast parts is too course to be used for stressed parts and too many potential flaws that are not visible happen, often showing up in hardening and tempering or, if they make it past those phases, in actual use.
In the days before investment casting became more commonly used (the late 19th Century),
stressed parts were forged, not cast. This was well withing the abilities of any gun maker or gunsmith, not only in large concerns like national armories and other major manufacturers but in small shops, even on the frontier here in America or in small out of the way facilities in Europe, Asia and Africa as well as South and Central America. Forged parts were easier to anneal, temper and harden as well.
Your "Aerospace degree" has an advantage over mine and I respect you for it, but you need to do research and study in history and art as well as business and manufacturing to get a better background in what was done in the past.