do monolithic copper bullets have the same range as monolithic lead or jacketed bullets?
Posted by how_to_glock43x@reddit | Firearms | View on Reddit | 8 comments
hello, i'm doing research into the differences between monolithic copper bullets, monolithic lead bullets, and jacketed bullets, and i'm trying to understand the difference in these things in terms of RANGE
and so what i'm understanding, is that monolithic copper bullets have greater velocity because they weigh less, but this also means that they lose velocity faster then jacketed bullets,
so does this mean that monolithic copper bullets have less range then a jacketed bullet or a monolithic lead bullet?
Resident_Skroob@reddit
Physics is physics.
If two objects with equal volume, equal shape, and equal coefficients of friction in the medium through which it moves (air) are propelled by the same force (The explosion that occurs inside the cartridge/chamber), and absent external variables (which absolutely never happens), the object with less mass will travel further, as there is less of "force" from the lighter object "pushing back" against the force of the explosion (Newton). That's a bit ELI5, but it's how I would literally explain it to my 5-year-old :-).
Take two cars that are completely identical on the outside as far as shape and coefficient of friction. They have the same engine on the inside. One car has a thousand pounds of weights stacked inside it. The car without the weights will be moved further than the car with the weights, given the same input of energy from the motor.
The material of the bullet or the jacket itself only affects coefficients of friction (how "slippery" is this material when it travels through air?), again assuming that the projectile shape, mass and volume are identical.
BloodWing155@reddit
You're right but missing the final piece - both bullets experience the same initial force, so yes the copper bullet will have a higher acceleration out of the barrel, but it will also experience higher deceleration from an equal force of drag through the air. Whether or not its enough to still beat the lead bullet I don't know, it would depend on the specific bullet type and trajectory.
Resident_Skroob@reddit
Yep, no disagreement. I tried to ELI5 it since I think OP wasnt clear on his question. I was trying to tackle one variable (mass, volume, shape, COF) to explain it. A lighter projectile will experience higher deceleration than a heavier one, all other variables (in this case, volume, shape, COF) being the same. I just didnt want OP (per his/her question) to think that what the bullet was made of was the deciding factor. All four variables I listed above would contribute to outcomes based upon his question. I didnt want to say "the brass projectile will decelerate faster" on its own, because if it weighed the same, had the same shape/volume, and had the same COF, what is was made of wouldnt matter.
Agammamon@reddit
Possibly. They'll have different ballistic arcs, certainly.
gravity_loss@reddit
Copper is less dense than lead so a copper projectile will be longer than a lead projectile of the same grain weight.
*Hornady 30 caliber VMAX (jacketed lead) 110 gr measures 0.93" long
*Hornady 30 caliber CX (monolithic copper alloy) 110 gr measures 1.21" long
Copper is less dense (harder) than lead so you need higher velocity to achieve proper expansion using the same grain weight projectile and, for the same reason, copper bullets retain more mass upon expansion (assuming they aren't going so fast that they simply explode upon impact).
Because they need more velocity for expansion you might be loading 110 or 130gr copper instead of 150 or 185 gr lead in, say, caliber 308WIN, using different load data to achieve higher velocity for a "similar" load. Additionally, lower grain weight copper bullets are also used because their greater length may not allow them to fit into the magazine and/or chamber properly, and if you just seat the copper bullet deep enough that it does fit you could potentially (and most likely) run into overpressure issues.
This is all to say- copper bullets don't have greater velocity than lead bullets of the same grain weight by virtue of their physical properties alone. Since copper is harder than lead, and with a larger bearing surface (generally) of the same grain weight lead bullet, it takes more energy to squeeze through the rifling. A copper bullet should have less muzzle velocity than a lead bullet of the same grain weight using an equal powder charge. However, you can't just load copper bullets using the same load data for lead bullets of the same grain weight.
This is only the very tip of the 'berg but I hope it helps you understand a little better.
Given the significant amount of variables I think it would be difficult to realistically quantify how far one vs the other will travel. In theory, absolutely. Ask a physicist.
This dude really knows his shit:
https://www.youtube.com/@GunBlue490
Good luck, have fun, be safe!
ediotsavant@reddit
Range is going to be a function of the ballistic coefficient (G1 or G7) for the copper monolithic projectile. If the G1/G7 is the same for two projectiles (copper mono vs a jacketed lead projectile) and the starting speed is the same then they will go the same distance.
However, copper monos usually have worse terminal performance than jacketed projectiles so it is entirely possible for a copper mono to have a shorter "effective range" than a similar jacketed lead core projectile.
DickMonkeys@reddit
So every time you have a random thought, you need to spam it to every gun sub on reddit?
Fluctuationism@reddit
I’m assuming by range you mean maintaining a certain velocity out to a certain distance? Because if you just measure the maximum distance that a bullet can go that’s gonna be incredibly far over an arc.
You’d have to measure specific loadings’s velocities at certain distances and compare the curves in speed.
Another thing to think about is wind displacement and bullet drop. If you want good wind displacement characteristics you want a heavy bullet. But heavy bullets tend to go slower, and thus drop faster over the same distance.
All in all, “range” isn’t really a term that people use because it’s somewhat useless to describe desirable or undesirable characteristics of various bullet types and powder loadings.