just for discussion, what would a near diamond hard projectile do to a barrel? - the actual projectile would be like a sabot or impregnated into a softer compound like copper.
How many rounds would you say a standard steel rifle barrel be able to launch? - great question with a composite depending on the modulus and harness none to a lot. it could fracture or be stable if not in contact with rifling. if in contact with rifling it would have to be able to withstand compression, which "some"/most composites cant. (think a broken arm casted in a mix of plaster and polymer). if something else is in contact with the rifling than indefinite depending on accepting material. soooo tangent vs secant ogive would make a difference. the flat part of the bullet should not touch the barrel. or maybee?/?? if you could tune compression and modulus with the proximal part of the projectile that might be an option. prox to distal being the metplat being distal
Would the rifling be able to engrave this hard projectile? based on answer above not quite sure. traditional rifling contingent upon weight and diameter and desired speed, if projectile is not actually contacting barrel. Ifyou could use a porous composite then yes.
What about the gasses that produce the thrust...how would such a hard projectile seal against leakage? - that is another great question, not to be obnoxious but these are all engineering design questions and this one is another great one. so one answer m855a1. if you can utilize a softer bonded material (either by mechanical or chemical bonding ) in a concentric manner than you can answer this because the softer deformable material can "block" the gasses and be used as the hydraulic pressure input. again another answer would be a sabot that utilizes the same principles. a new age answer would be to model the stress in the barrel (utilizing a similar composite) to transfer all the kinetic energy.
Or would this projectile have a sort of diamond core? And for what purpose...defeating armor? another fantistic q. soooooooo two answers brittle and hard would break ceramic body armor. break being a key word. impact with a similar toughness and compression strength. UHMPE would be essentially fucked. It would be the absolute opposite of barrier blind unfortunately. but can gain value in its utility against BA. for civi market it would not penetrate walls al day.....
If the projectile does not touch the barrel...
Using todays technology, the rifling imparts spin to the projectile which then provides stability in the form of centripetal motion. If your projectile does not touch the barrel, how will you stabilize it in flight?
Using a modern rifle, you are going to want that projectile to be engraved by the barrel and so you are going to need to design the projectile so that the zirc is not on the steel.
That spin motion can create another problem in that it can destroy the projectile. This is especially true with jacketed bullets and occurs around 300,000 rpm. If you have a zirc core and some (EDIT: I said "polymer" when I should have been using the word composite. Composite does not necessarily mean a polymer) outer, the bond will need to withstand the centripetal forces.
Weight? I recall the testing of the rail guns on Navy ships using an extremely lightweight plastic pellet at extreme or even hyper-velocity. They had trouble with accuracy, amongst many other problems, apparently insurmountable using current technology. Using a
polymer composite, assuming it weighs less than lead or bismuth or steel, you have to start making a real long projectile in order to have the weight (mass?) for stable flight. That length then becomes an issue by being able to be fed from from a magazine, the free bore in the barrel, etc.
Porous, to me, is counterintuitive to creating an object that behaves in free flight.
I don't know, man, maybe use zirc instead of the steel pin as is used in the SS109 ammo. How would that be beneficial? I don't know if there is enough advantage gained to make the manufacturing switch.
I still have a shit load of the 30 cal bullets that hold a 22 cal projectile. I also have some vintage Remington factory ammo, Accelerators, for 30-06. The sabot concept is cool but they are shit for accuracy beyond maybe 125 yards.