Tube Magazine Fed Bolt-Action Rifle—Cal .30-30 Winchester. Student: Dallas CLAYTON DAIGLE Concentration: Mechanical Class: ET 493 Spring 2015 Instructor: dr. chris koutsougeras Advisor: dr. junkun ma.

Introduction There have been few developments around the .30-30 in many years. Most .30-30 Firearms are lever action. Lever actions inherently have exposed hammers and many moving parts. Space concerns and inherent danger with exposed hammers. Lever actions can be difficult for inexperienced shooters. Especially older models.

Introduction—Contd. A Bolt action would eliminate the need for an exposed hammer by having firing components contained within the bolt. This makes them inherently safer than their lever operated counterparts. The .30-30 Win has a pronounced rim, which often catches on the followers of traditional box magazines. The rim and the blunt nose of the round are the reasons behind tubular magazines being ideal for the .30-30 Win.

Objective(s) Create an safer design for the .30-30 Winchester. This design utilizes a bolt action rather than a lever action. It retains the tubular magazine running under the barrel. The chief idea/objective is to retain the pros of both types of actions while eliminating their respective cons.

Design Challenges Action/Mechanism must be designed to reliably and safely complete the firing  ejecting  feeding  reloading cycle repeatedly until magazine is empty. The chamber/barrel/headspace needs to be designed to handle a variable working pressure with a maximum of 42,000psi (290Mpa). Custom barrel, magazine assembly, receiver/housing and internal mechanisms must be designed and adapted to meet a standard bolt and trigger assembly. The whole system should be light and compact, with internals that are simple and reliable, and made of specifically selected materials. It needs to be easily disassembled for cleaning, and need little maintenance to function smoothly.

Mechanism Description

Breakdown of Designed Components and Methods. For this project, many custom components had to be designed to meet the known parameters. The following slides/sections will break down and discuss these components in detail. Design, dimensions, function(purpose), and modeling will be discussed.

The Carrier.

Modeling the Carrier

The Barrel. The initial plan was to design a new barrel. One that was harmonically stable for maximum accuracy, was of the appropriate thickness to deal with the developed pressure/stress, and had the ideal rifling ratio. After doing some of the calculations, it was established that the standard was already very close to this ideal case, so there was no need for a custom barrel. For redundancy and modeling purposes, I went ahead with the hand calculations, but only used the ones for the chamber/headspace.

Designing the Barrel/Headspace To find the thicknesses needed for the barrel, the barrel was modeled as a thin-walled pressure vessel. In this way, based on the design stress, the formula for thin walled hoop stress can be re- arranged to produce this thickness. Chosen Material: ANSI 4140 OQT900. Yield Stress: 173ksi. Design Factor: 2. Design Stress: 𝜎 𝑑 = 173𝑘𝑠𝑖 2 =86.5𝑘𝑠𝑖.

Designing the Barrel/Headspace (Contd.) The thickness can now be found with the alternate version of the thin-walled hoop stress formula: 𝜎= (𝑃)( 𝐷 𝑖 ) 2(𝑡) Inputting all the necessary data produces a wall thickness of .07477”. This can be used to find the outer diameter of the headspace as follows: 𝐷 𝑜 = 𝐷 𝑖 +2 𝑡 = .45755”

Modeling the Barrel/Headspace.

Magazine Retention Device. Regulates rounds leaving the magazine. In this case, limiting to one per loading cycle. Spring assisted. Functions as a simple lever.

Magazine Assembly.

The Bolt.

Receiver/Housing

Deliverables Conceptualize and complete rifle/mechanism design. (Complete) Compile all necessary data. (Complete) Complete all necessary calculations. (Complete) Choose best material(s) based on calculations. (Complete) Build assembly model prototype in SolidWorks. (Complete) Complete analysis of all parts in COMSOL. (Tentative—In Progress) Total build cost estimation. (Tentative—In Progress)

Timeline Start Conceptualizing Idea/Potential Designs……………..January 20th-27th 2015 Begin Learning SolidWorks……………………………………..….March 2nd 2015 Complete Initial Design Concept/Drawing……………….…March 17th 2015 Complete Proposal and Presentation…………………………March 27th 2015 Final Design and Calculations……………………...…………....April 13th 2015 Complete Part Drawings and Assembly Model………..…May 5th 2015 Complete Analysis on all Parts………………………………..….May 5th 2015 Final report and Presentation.…………………………………...May 8th 2015

Goals for Next Semester Finalize Fully Functional Design (Summer—Early Semester). Identify and Complete Hardware (Screws, Springs, etc.). Tolerance and Function Testing in SolidWorks. In-Depth Materials Science (Surface Hardness, Frictional Stresses, FEA, etc.). Further Calculation as Needed. COMSOL Analysis. [Tentative] Cost Analysis/Estimation. 3D Printed Display Assembly Model.

Questions? THANK YOU—THE END.