Wouldnt it be easier and cheaper to make the entire bullet copper rather than putting a copper jacket around a lead core or steel core? What exactly is the purpose?
It is more elaborate than just a matter of having a easy barrel. Ope Lead bullets - allow you to fire 1,000,000+ rounds in a barrel with nearly no measurable injury when you consider that the lead is so tender. Lead goes down the barrel like hot butter on Teflon. Copper jacket - go like sandpaper and can put on out a barrel in as little as 8,000 rounds. Nevertheless, any powder charge so that it will ship a projectile faster than 1100 fps - will lead the barrel. Even copper gas tests - restrict the velocity to 1800fps or so. So, in order for a contemporary hunting rifle to fireplace a bullet at 2800fps and extra - it ought to use a copper jacket or full copper bullet. Lead, in itself - does now not reason corrosion. Neither does copper. Nearly all of corrosive chemical substances come from the burnt and unburnt powder residue left within the barrel after firing....... The metal naturally attracts moisture from people respiratory, cooking, bathing and so on within the residence and this combination of moisture and chemical substances varieties acids that devour the metal over time.
There actually are entire bullets made from copper. Except that these are much more expensive than normal FMJ bullets. I've linked you a video that shows such bullets being made, and it really is fun watching them shave a single bullet out of a solid copper block. Solid copper bullets are more expensive due to the equipment used and the materials wasted. They do produce a superior bullet though. The purpose of a copper-nickle jacket is to keep the bullet together while it is traveling at very high velocities. It also keeps it from leaving too much lead on the barrel grooves. Finally it does assist in penetration, though it does degrade a bullet's expansion at the same time.
You have good answers here, but also some misinformation. It is impossible for a solid copper bullet to have a ballistic coefficient superior to a lead-core bullet of the same caliber. Ballistic coefficient is a function of mass, diameter and drag coefficient. The more mass, the higher the BC, so that means that copper, which is not as dense (massive) as lead, will always have a lower BC. That is why you will not find copper solids on the line for long-range competition at the National Matches or any other long-range discipline.
1. You can not melt copper and cast bullets easily. 2. Copper bullets will not have the weight to be effective bullets. 3. Copper is way too expensive for bullets. Lead is far cheaper.
There are some entirely copper bullets for the record. However, originally lead was used because it was soft enough that the bullet would expand under pressure and bite into the riflings of the barrel, forcing it to spin and hence be more accurate. Also lead had the advantage of being quite dense so you have a low surface area to weight, making the bullet more aerodynamic. (even in the days when people use slings, lead was often used to make the projectiles because it was so dense) a copper jacket allows the lead bullet to be fired at greater pressures and greater speed without it coming apart in the barrel or in flight. The lead also mushrooms allowing both good penetration and good expansion. All-copper bullets either just punch right through, or they have to be designed to break apart inside the target
