The paper is prepared as continuation of the previous publication and investigates the efficiecny of half-bridge coilgun basing on real examples. FEMM simulation is used to predict efficiency of both half-bridge and simpler competitive circuit with varistor at high initial velocity of projectile.

Simple equations are presented to assess so called "characteristic speed" of projectile in a coilgun, which specifies the moment when kinetic power equals to ohmic losses of the acceleration process. 

There is often need to assess some parameters of coilgun (e.g. peak current to choose an appropriate power switch) quickly. Exact formulae (given here) may be used, but it is more convenient to establish few simple relations. 

This section collects such relactions for different cases.

Variation of the parameters such as capacitance, initial projectile velocity etc and its influence on acceleration efficiency  is analyzed for two base configurtions of the accelerator - with and without feedback.

During the work on EM-2 and EM-3 projects, the author of this paper has performed some experiments and calculations, which resulted in creation of unfinned arrow for electromagnetic accelerator.  Nonetheless, I became interested in this question and (after EM-3 projected was finished) decided to conduct more detailed investigation, which is described in this paper.

This short article considers mathematical estimation of the projectile spread during reluctance accelerator shooting. Using simple formulae, conservative assessments are conducted for cylindrical and sphere-shaped projectiles.

Analytical solution describing recuperation of the energy for the diagonal halfbridge scheme is performed. Efficiency is analyzed for variety of conditions inherent to the real coilgun implementations.

Basic equations for current and voltage in RLC-circuit of one-stage coilgun are presented in this article. Using them, some interesting specific cases of practical importance are analyzed (for example, current decay in a half-bridge recuperative coilgun).