Force and Motion Grade 8 project with Firearm

[ScienceDad]

My son is currently planning a science fair project for presentation in February 2011 at his school. He would like to do something around the different force and subsequent penetration of a projectice into a standard material. He has come up with an idea to shoot different types of bullets into a block of plywood and then seperate the block into the sheets and measure the penetration of the projectile. He is thinking of using hollow point vs hard point bullets.

We are members of a firearms club and have access to a safe facility to have him conduct the tests. The firearms used would only appear in his display as photos. The contolled variables would be the firearm and weight of projectiles.

The challlenge is in presenting the information related to force and motion as it relates to the school science curriculum.

Does this seem a reasonable project?

[deleted-71588]

While this is an intersting idea, there are a lot of uncontrollable factors that make experimentation in this area difficult not to mention range safety issues.

Plywood (or any grained material) will introduce significant differences. Even different locations in the same block may have significantly different behaviors. Essentially you won't have a "standard material".

Variations in the muzzle velocity that can be attributed to the chamber fit, primer, combustion rates, gas leakage points between the shell and the cartridge are all uncontrollable variables. When you introduce different projectile shapes into the mix, the crimp between the cartridge and the projectile can easily become a significant factor in the muzzle velocity. The projectile shape will affect the aerodynamics and thus affect the target velocity in addition to any deformation of the projectile at target impact.

Small safe ranges restrict the use to paper targets and have soft earthworks or similar material as a containment. Ranges that utilize clay targets restrict the use to shotgun shells of a given type of load to reduce richochet and range danger distances. These safety restrictions are important to reduce risk. Military style ranges used to assess target damage involve either the use of gun ports and/or firing fixtures with long stand off distances.

You also should consider the possibility that judges/teachers/students/parents may have a bias against any firearm project.

So, I've given you scientific/engineering reasons why controlling the project is difficult, I've given you range safety issues to be dealt with, and I've given you "political" bias reasons why this might not be a good project.

[deleted-71823]

I definitely agree with Craig. This is an excellent project but is not suitable for a school science project. A board judging students will not find this particular experiment user friendly. It is not a project that they will want to award either. Another aspect of the judging that you may want to take into account is that you will have to help your son out quite a bit with this project. Judges look for projects where the students did almost all of the work by themselves. I highly recommend finding another project.

[ScienceDad]

I did recognize the inconsistencies in the target mass in using plywood. We had considered ballistic gel however to practicality of making, molding and transporting to the range are challenges. It also needs to be kept within certain temperature ranges for it to remain stable. I also appreciate your thoughts on the political correctness of such a display. Thanks very much for your feedback, I will discuss this with my son.