Fig. 1. Raman spectrum of five samples

Fig. 2. Microscopic forms of five samples
(a): Propellant particles; (b1): Residue particles in the barrel; (b2): Residue particles in the barrel;(c): Residue particles after burning propellant; (d): Shot residue in hand; (e): Target shooting residue

Fig. 3. Raman spectra of different excitation wavelengths

Fig. 4. Raman spectra of different objective conditions