Just a little thought on the .75 ID X .250 wall "seamless tubing".
Most of the 'seamless tubing' around is not truly seamless. It is usually welded tubing which has been drawn over a mandrel and thru a die. It is more correctly called DOM (Drawn Over Mandrel).
This process gives the tubing a smooth appearance and, indeed, this smoothness helps the tubing to seal with the various fittings commonly used in tubing applications.
If it is DOM, it is a welded tube, and is not as strong as a true 'seamless tube' which is formed by forging.
Because the material the tube is made from is unknown, and the process of making it is also in question, I cannot say that it is suitable for housing an explosive safely.
I can say that after calculating the pressures that a mild steel piece of tubing with the dimensions given above it appears that if the tubing was actually 'seamless' and not DOM, it would be good for dynamic hydraulic pressures of over 10,000 PSI however in the case of a sudden application of pressure as is found in a firearm, it is recommended that the safe maximum pressure must be reduced by at least 1/2.
Although the tube has a .250 wall, this thickness will be reduced after the inside is threaded for a breech plug. This threading will exist right in the area where the greatest pressure is developed when the powder ignites.
This, coupled with the fact that this is a life/death situation makes me hesitant to suggest that a gun made from this material would be safe to fire.
zonie
