When complete, this collection of ballistics programs will enable the estimation of all the ballistic information needed from "click" to "thump". It is intended that the programs should give the most accurate results available in the most accessible way, so ease of use has been of prime concern in designing these programs. All the programs are accessed on-line and the interface is via your browser, so there is nothing to download and there are no operating system problems. If you can read this, you can run the programs. Internal ballistics simulator This is a program that is unique on the Internet. Like the well known QuickLOAD program, this is numerical computer model of what happens after the powder in a firearms cartridge ignites. But unlike the QuickLOAD program, this app is online and free at the point of use. The powder choice is very limited at the moment, but it is early days and we are hard at work trying to increase the repertoire of powders. Go over to BBT and give it a go. Tell us what you think! Trajectory This does what lots of external ballistics programs do. Enter a muzzle velocity and a Ballistic Coefficient and the program will plot a table of drops, wind deflections, velocities and energies for ranges from 50 yards up to 1000 yards. But this program will do a lot more besides. . . Barrel twist After the dimensions of the bullet of interest are entered, the program will give you a graph of the barrel twist required to stablise the bullet as a function of muzzle velocity. Drag curve to trajectory program This is the best external ballistics program you will find outside commercial offerings costing thousands of dollars. Just put the bullet dimensions in at one end and a full ballistics table of drops, wind drifts, velocities and energies for ranges from 50 yards to 1000 yards will emerge at the other end. On the way, the program calculates the G1 and G7 Ballistic Coefficients for a range of Mach numbers, as well as barrel twists required to stabilise the bullet, and a curve for Drag Coefficient against Mach number. The ultimate tool for the bullet designer. Vibrations on a rifle barrel This is another program that is unique on the Internet. It allows you to use a sophisticated finite element program to model the vibrations created in a rifle barrel by the recoil forces. This model appears to reproduce the results of other computer models for the same barrel configurations, and to be in reasonable agreement with the results of experimental studies of the vibrations of small arms rifle barrels.