My dad had the smae thing with his 30-06. When he shoots at dusk it has an 10-12in fireball come out of the barrel. Ive never shot my 204 at dark so i dont know if it dose it but i will expect it to. As for the 204 compared to a 243. The 204 is alot smaller then a 243. Its more comparable to a 17 Rem, 223, 222.