Development, instrumentation, and analysis of recoil through a riflescope

Abstract

The research and development of new technologies to incorporate in the sport optics field have orientated the design, development, and construction of new riflescopes with state-of-the-art materials, processes, and technology. With each evolution, the riflescope should be evaluated to observe and acquire data on how the riflescope behaves during recoil. For this, the data acquisition and test setup should be easy to maintain, portable, and fast setup addition, measurements should be repeatable and low-cost. A literature review was conducted to check what has been done, what sensors and data acquisition controllers were used, the setup type, and the results. The sensor selection process required numerous specifications to filter the possible sensors for the ideal selection. The main factors and basis for the appointment were weight, G force, frequency, and price. The calculated theoretical max acceleration suffered by the rifle setup is 114g. The sensor also must be easily mounted/unmounted to/from the riflescope body. Furthermore, the sensor should be rigidly fixed not to suffer any unnecessary vibration from the interface and interfere with the measured data. Finally, the data acquisition should be accomplished relatively quickly to measure all the necessary data points. Sensors and accessories from various manufacturers were researched that fit the requirements. However, due to cost limitations, the selected sensor was the ADXL372.The testing setup includes a rifle and riflescope assembly on a stand. The sensor is guided and fixed on the riflescope, and a microcontroller reads and stores the acquired values. As a result, the testing setup is easy to transport and has a quick and repeatable structure. The measured acceleration values can calculate acceleration curves, displacement, velocity, and forces. The setup is ideal as it can be used to monitor the riflescope reaction on each test point, and results can have many uses, such as validating a numerical model FEA simulation. This paper will present and discuss the instrumentation and setup needed to read acceleration values on a riflescope from the firearm recoil and analyze the data for further use and interpretation.