dingerr and I have been having a bit of a discussion regarding the luminary abilities of WP and it's time to start it's own thread to get a wider viewpoint. I've come across a few posts (mostly US blogs) that suggest that some US illuminating ammunition provides light from a WP composition. dingerr insists that WP is solely used to produce smoke, stating: While I would not disagree vehemently with the gist of dingerr's comments, I can see some holes in his arguments. These are: The British use of WP as a smoke generator requires the missile to burst apart on striking the ground, spreading the WP over a large area. In this scenario, the brightness of the flame is obscured by the smoke that spreads around it. Indeed, it is the brightness of the flame reflecting off the smoke particles that aids obscuration. Were the WP to be deployed in the base of a parachute-retarded munition, the ejected smoke would rise above the munition due to both thermal convection and also the descent of the munition. The smoke would therefore not obscure the light but would reflect the light towards the ground. To some extent this would provide less harsh illumination of the battlefield than is the case using British illuminating rounds. Because the WP is not burst from the projectile, I'd presume that the smoke would be less dense and a longer duration of illumination would result. So, has anybody any experience of a WP illuminating round? And are there any ATOs who can throw in some technical comment?