I second that audioguru.
This probably doesn't have much place, as it may not help you directly, but 'coil guns' are woefully inefficient...and you can make it as big as you like, that won't change. Try a 'rail' gun instead, much more efficient, less hassle. Either that or stop using standard coils, try different shapes. Even better use aluminium tubing as the projectile, as the lorentz law will come into play, so your coils will attract - then repel - the projectile.
Maybe I'm just a perfectionist, but I prefer clever engineering to brute force, much more elegant
Blueteeth
This probably doesn't have much place, as it may not help you directly, but 'coil guns' are woefully inefficient...and you can make it as big as you like, that won't change. Try a 'rail' gun instead, much more efficient, less hassle. Either that or stop using standard coils, try different shapes. Even better use aluminium tubing as the projectile, as the lorentz law will come into play, so your coils will attract - then repel - the projectile.
Maybe I'm just a perfectionist, but I prefer clever engineering to brute force, much more elegant
Blueteeth