Firearms Law and Internal Ballistics - lect 14

General Reminders

• Work with presentation groups on presentations.

• Meet in person, online, or both to prepare content and practice deliveries.

• Don't postpone presentation preparation.

• Attend labs for ballistics and analytics.

• Write up lab reports after each session to avoid falling behind.

• Ballistics labs this week for those who didn't have them last week (Wednesday or Friday).

Air Guns and Legal Definitions

• There's a general limit that defines air guns legally.

• 'Specially dangerous' air weapons:

  • Air rifle: around 16 joules.

  • Air pistol: around 8 joules at the muzzle.

  • Equivalents: 12 foot pounds for a rifle, 6 foot pounds for a pistol.

• Rifle above 16 joules: section one firearm.

• Pistol above 6 foot pounds (8 joules): prohibited weapon, section five (treated like a handgun).

• Portable or handheld weapons have barrels > 30 cm and overall length > 60 cm.

• Important to remember these numbers for definitions (exam).

Muzzle Energies in Context

• Air weapon limit: 8 and 16 joules.

• Rimfire ammunition: 140-280 joules.

  • Point .22 LR (Long Rifle) rimfire ammunition.

  • Uses propellant, creating much more energy than air propulsion.

• 5. 56 x 45mm (typical assault rifle): 1,600-2,200 joules.

  • Centerfire systems.

• Rimfire: primer in the rim of the cartridge.

• Centerfire: centerfire primer cup in the base of the cartridge.

• Energy increase:

  • Airgun to rimfire: 10x increase.

  • Rimfire to centerfire: 10x increase.

• Semi-automatic weapons: rimfire allowed (section one firearm), centerfire not allowed.

• 7. 62 (larger assault rifle/machine gun): higher energy than 5.56.

• Shotguns: range of energy outputs based on pellets or slugs.

• Need to understand typical numbers for different firearm systems.

• Important to have a feeling of reasonable numbers when calculating kinetic energy.

Deactivation of Firearms

• Deactivation: process to take a live firearm outside its classification.

• Section 8 of the 1988 Amendments Act: certification to confirm deactivation.

• Definition: incapable of discharging any shot, bullet, or missile.

  • Cannot launch something > 1 joule.

• Must have a mark and certificate approved by the Secretary of State (Home Office).

• Proof houses: test new firearms and certify deactivation.

• Proof markings: stamped on components to show they withstand high pressures (20% over pressure ammunition).

• Deactivation mark and certificate: details and serial number of the deactivated firearm, signed by the Proofhouse Master.

• Guidelines changed over the years, major change after 1995 due to incidents.

• Firearms deactivated prior to 1995 are accepted.

  • More moving components, easier (in theory) to convert back to a live firearm.

  • Post-1995: very hard to make functional again.

• Weapons may be deactivated through other means (e.g., old gun or cannon on a shipwreck).

  • May no longer maintain pressure or fire effectively if rusted/corroded.

• Main deactivation processes:

  • Steel rod welded down the barrel to block the muzzle and prevent projectiles from exiting.

  • Removal of internal mechanisms (automatic loading, firing pin movements).

• Pre-1995 deactivations:

  • Often have internal mechanisms, are more functional, and good teaching aids.

• Deactivation vs. damaged parts:

  • Deactivated: overall system damaged beyond repair.

  • Damaged parts: not deactivated if parts can be swapped out.

• Final Arbiter: the court system; court law and case law relate to trials and cases.

Section Reminders

• Section One:

  • Standard firearm, bolt action rifles (unless in rimfire, can be semi-automatic).

• Section Two:

  • Shotguns, strict definitions (barrel length, bore diameter, number of shots, non-revolver, and non-removable magazine).

• Section Five:

  • Everything else, unless unclassified.

Classification Examples

• Grenade (replica): unclassified because replica.

• Mini Uzi (machine pistol/submachine gun): Section Five due to concealability (barrel length < 30 cm, overall length < 60 cm).

• Electric minigun: Section Five due to very high rate of fire, military weapon.

• Shotgun (cut off barrel): Section Five due to short barrel (less than 24 inches).

• Pump action shotgun: Needs measurement; likely Section Five if too short.

• Target rifle: Bolt action, centerfire system, Section One.

• Massive .50 caliber firearm: Bolt action rifle, Section One (but need a reason and place to use it).

• Military/police type firearm (small assault rifle/personal defense weapon): Section Five.

• Military assault rifle: Section Five (automatic capabilities, semi-automatic with centerfire).

• Caveat: military assault rifles can be converted into straight pull single shot systems, making them Section One.

General Considerations for Classifications

• Don't take things at face value.

• Physically look at and touch the firearm.

• Check for modifications.

• Modified weapons need to be reproofed and have a certificate.

• Consider all sections and what makes each firearm what it is.

Challenges Related to UK Firearms Law

• Balancing firearms control with supporting sporting endeavors, land management, and farming.

• Genuine uses for firearms in the community need to be supported.

• Restricting access within reason without being too onerous.

• Ultimate goal: protect public safety.

Internal Ballistics: Introduction

• Focus on internal mechanisms.

• Common defense in accidental shootings: something went wrong with the firearm.

• Understanding internal processes is important (change plea from murder to manslaughter).

• Objectives:

  • Understand internal mechanisms by which firearms are discharged.

  • Examine processes that occur.

  • Break down what happens inside into three stages: lock time, ignition time, barrel time (from trigger pull to bullet leaving muzzle).

  • Explore the operation of different types of safety mechanisms.

  • Consider physical tests for investigations.

What Happens Inside a Gun?

• Three main phases of ballistics:

  • Internal ballistics: inside the firearm.

  • External ballistics: projectile flying through the air.

  • Terminal ballistics: at the target.

• Internal ballistics has lots of complicated events.

  • Chain of events leads to chamber pressures > 3,500 atmospheres.

  • Propel a projectile down the barrel.

  • Velocities can exceed 1,000 meters per second.

  • All happens in as quick as about 20 milliseconds.

• Internal efficiency is also investigated.

Internal Ballistic Process

• Ammunition in chamber, trigger pulled, movement in the system:

  • Levers cause firing pin to come forward, impacting primer.

  • Primer explodes, jets of hot material through flash hole to propellant.

  • Propellant burns, gas production, pressure builds.

  • Bullet goes down the barrel.

• Self-loading mechanism: ejects cartridge, loads next one.

Three Major Phases of Internal Ballistics

• Lock time, ignition time, barrel time.

Lock Time

• Lock time: time between activation of firing mechanism (trigger pull or electromagnetic activation) and ignition of the primer charge.

• Movement from trigger pull to movement of firing pin assembly to impacting the base of the cartridge case.

• Dependent on the trigger mechanism and its translation of motion.

• Trigger mechanism: mechanical system, tight tolerances.

  • Changing curvature of levered surfaces changes sensitivity.

• Trigger pull sensitivity depends on the intended use of the firearm, can range from hair trigger to very heavy trigger.

• Trigger mechanism consists of levers (sears) that hold the firing pin or hammer under spring pressure until the trigger is operated.

• Electromagnetic or electrical triggers operate differently.

• Safety didn't work is commonly alleged in accidental shootings.

• Firing pin spring is compressed and held by a sear; pulling the trigger releases it, activating the primer.

• Most modern firearms have multiple safety mechanisms (drop safeties).

• Most common failure: operator.

Trigger Safety

• Physically blocks pulling the trigger.

• Simple push-across button.

• May flick on automatically after the shot or require manual activation.

• Blocks trigger movement, but internal mechanism is still free to move.

Sear Safety

• Mechanical safety that blocks one or more of the trigger sears.

• More reliable than trigger safety.

• If the direct attachment between the sear/safety and the firing pin is damaged, the firing pin can still go.

• Includes grip safeties (safety button in grip). Need to hold the grip to compress the button and allow things to function.

• Different types of firearms have different structures and numbers of sears.

• Need to be able to recognize some of the key components on a technical diagram.

• Grip safety: Is a type of sear safety (interacts with levers that release the firing pin).

• All sears are going to revolve over time and eventually get to a point where they become dangerous.

• It is the owner's responsibility to judge when the sears are feeling too light and get some of the internal pieces replaced or refurbished or take them to a gunsmith to have it looked at.

• Firearms should be regularly maintained so that a qualified gunsmith can rebuild them.

General Reminders

• Work with presentation groups on presentations. Ensure that all members actively contribute and that the workload is evenly distributed.

• Meet in person, online, or both to prepare content and practice deliveries. In-person meetings can facilitate better collaboration, while online meetings offer flexibility.

• Don't postpone presentation preparation. Start early to allow ample time for research, content creation, and rehearsals.

• Attend labs for ballistics and analytics. These labs provide hands-on experience and are crucial for understanding the practical applications of the course material.

• Write up lab reports after each session to avoid falling behind. Consistent report writing helps reinforce learning and provides a record of experimental findings.

• Ballistics labs this week for those who didn't have them last week (Wednesday or Friday). Check the schedule and attend the appropriate session.

Air Guns and Legal Definitions

• There's a general limit that defines air guns legally. Understanding these limits is essential for compliance and safety.

• 'Specially dangerous' air weapons:

  • Air rifle: around 16 joules. This threshold is a key legal marker.

  • Air pistol: around 8 joules at the muzzle. Lower energy limit compared to rifles.

  • Equivalents: 12 foot pounds for a rifle, 6 foot pounds for a pistol. These are the imperial unit equivalents for energy.

• Rifle above 16 joules: section one firearm. Exceeding this limit reclassifies the weapon.

• Pistol above 6 foot pounds (8 joules): prohibited weapon, section five (treated like a handgun). Higher regulation due to increased risk.

• Portable or handheld weapons have barrels > 30 cm and overall length > 60 cm. These dimensions define what is considered a portable firearm.

• Important to remember these numbers for definitions (exam). These values are critical for accurate classification and legal understanding.

Muzzle Energies in Context

• Air weapon limit: 8 and 16 joules. These values provide a baseline for comparison.

• Rimfire ammunition: 140-280 joules.

  • Point .22 LR (Long Rifle) rimfire ammunition. A common type of rimfire ammunition.

  • Uses propellant, creating much more energy than air propulsion. Chemical propellants significantly increase energy output.

• 5.56 x 45mm (typical assault rifle): 1,600-2,200 joules.

  • Centerfire systems. This is a standard cartridge for many modern rifles.

• Rimfire: primer in the rim of the cartridge. The primer's location defines this ammunition type.

• Centerfire: centerfire primer cup in the base of the cartridge. The primer's location defines this ammunition type.

• Energy increase:

  • Airgun to rimfire: 10x increase. Significant jump in energy levels.

  • Rimfire to centerfire: 10x increase. Another substantial increase in energy levels.

• Semi-automatic weapons: rimfire allowed (section one firearm), centerfire not allowed. Legal restrictions on semi-automatic centerfire weapons.

• 7.62 (larger assault rifle/machine gun): higher energy than 5.56. Larger rounds produce more energy.

• Shotguns: range of energy outputs based on pellets or slugs. Versatile ammunition types lead to varying energy levels.

• Need to understand typical numbers for different firearm systems. Essential for accurate assessment and comparison.

• Important to have a feeling of reasonable numbers when calculating kinetic energy. Estimation skills are valuable in practical applications.

Deactivation of Firearms

• Deactivation: process to take a live firearm outside its classification. Rendering a firearm permanently inoperable.

• Section 8 of the 1988 Amendments Act: certification to confirm deactivation. Legal requirement for verification.

• Definition: incapable of discharging any shot, bullet, or missile.

  • Cannot launch something > 1 joule. Strict limit to ensure complete inoperability.

• Must have a mark and certificate approved by the Secretary of State (Home Office). Official documentation is required.

• Proof houses: test new firearms and certify deactivation. Specialized facilities for testing and certification.

• Proof markings: stamped on components to show they withstand high pressures (20% over pressure ammunition). Indicates the firearm has passed safety tests.

• Deactivation mark and certificate: details and serial number of the deactivated firearm, signed by the Proofhouse Master. Provides a verifiable record of deactivation.

• Guidelines changed over the years, major change after 1995 due to incidents. Evolving standards due to security concerns.

• Firearms deactivated prior to 1995 are accepted.

  • More moving components, easier (in theory) to convert back to a live firearm. Older deactivations may not be as secure.

  • Post-1995: very hard to make functional again. Modern deactivations are designed to be irreversible.

• Weapons may be deactivated through other means (e.g., old gun or cannon on a shipwreck).

  • May no longer maintain pressure or fire effectively if rusted/corroded. Natural degradation can also render firearms inoperable.

• Main deactivation processes:

  • Steel rod welded down the barrel to block the muzzle and prevent projectiles from exiting. Physical obstruction to prevent firing.

  • Removal of internal mechanisms (automatic loading, firing pin movements). Disabling key components to prevent functionality.

• Pre-1995 deactivations:

  • Often have internal mechanisms, are more functional, and good teaching aids. Useful for educational purposes due to their completeness.

• Deactivation vs. damaged parts:

  • Deactivated: overall system damaged beyond repair. Comprehensive damage ensures inoperability.

  • Damaged parts: not deactivated if parts can be swapped out. Replaceable parts do not constitute deactivation.

• Final Arbiter: the court system; court law and case law relate to trials and cases. Legal interpretations determine the final classification.

Section Reminders

• Section One:

  • Standard firearm, bolt action rifles (unless in rimfire, can be semi-automatic). Defines typical firearms with specific actions.

• Section Two:

  • Shotguns, strict definitions (barrel length, bore diameter, number of shots, non-revolver, and non-removable magazine). Specific criteria for shotgun classification.

• Section Five:

  • Everything else, unless unclassified. Catch-all category for highly restricted firearms.

Classification Examples

• Grenade (replica): unclassified because replica. Non-functional items are not subject to firearms laws.

• Mini Uzi (machine pistol/submachine gun): Section Five due to concealability (barrel length < 30 cm, overall length < 60 cm). Compact size leads to stricter regulation.

• Electric minigun: Section Five due to very high rate of fire, military weapon. High-capacity, rapid-fire weapons are highly restricted.

• Shotgun (cut off barrel): Section Five due to short barrel (less than 24 inches). Illegal modification leading to reclassification.

• Pump action shotgun: Needs measurement; likely Section Five if too short. Length restrictions apply to pump-action shotguns.

• Target rifle: Bolt action, centerfire system, Section One. Standard configuration for target shooting.

• Massive .50 caliber firearm: Bolt action rifle, Section One (but need a reason and place to use it). Requires justification for ownership and use.

• Military/police type firearm (small assault rifle/personal defense weapon): Section Five. Designed for military or law enforcement use.

• Military assault rifle: Section Five (automatic capabilities, semi-automatic with centerfire). Automatic and semi-automatic centerfire rifles are heavily restricted.

• Caveat: military assault rifles can be converted into straight pull single shot systems, making them Section One. Modification can change the classification.

General Considerations for Classifications

• Don't take things at face value. Always verify the specifications and condition of the firearm.

• Physically look at and touch the firearm. Hands-on inspection is crucial for accurate assessment.

• Check for modifications. Alterations can affect the classification of the firearm.

• Modified weapons need to be reproofed and have a certificate. Legal requirement to ensure safety and compliance.

• Consider all sections and what makes each firearm what it is. Comprehensive understanding of the law is essential.

Challenges Related to UK Firearms Law

• Balancing firearms control with supporting sporting endeavors, land management, and farming. Reconciling public safety with legitimate uses.

• Genuine uses for firearms in the community need to be supported. Acknowledging and accommodating lawful activities.

• Restricting access within reason without being too onerous. Implementing proportionate regulations.

• Ultimate goal: protect public safety. The primary objective of firearms legislation.

Internal Ballistics: Introduction

• Focus on internal mechanisms. Studying the workings of firearms.

• Common defense in accidental shootings: something went wrong with the firearm. Mechanical failure is often cited in legal cases.

• Understanding internal processes is important (change plea from murder to manslaughter). Knowledge of ballistics can influence legal outcomes.

• Objectives:

  • Understand internal mechanisms by which firearms are discharged. Gaining a comprehensive understanding of firing processes.

  • Examine processes that occur. Analyzing the sequence of events inside a firearm.

  • Break down what happens inside into three stages: lock time, ignition time, barrel time (from trigger pull to bullet leaving muzzle). Temporal decomposition of the firing sequence.

  • Explore the operation of different types of safety mechanisms. Studying various safety features and their functions.

  • Consider physical tests for investigations. Applying forensic techniques to examine firearms.

What Happens Inside a Gun?

• Three main phases of ballistics:

  • Internal ballistics: inside the firearm. The study of processes within the firearm.

  • External ballistics: projectile flying through the air. The study of projectile motion.

  • Terminal ballistics: at the target. The study of projectile impact.

• Internal ballistics has lots of complicated events.

  • Chain of events leads to chamber pressures > 3,500 atmospheres. Extreme pressures generated during firing.

  • Propel a projectile down the barrel. Acceleration of the bullet through the barrel.

  • Velocities can exceed 1,000 meters per second. High-speed projectile motion.

  • All happens in as quick as about 20 milliseconds. Rapid sequence of events.

• Internal efficiency is also investigated. Assessing the performance of the firearm.

Internal Ballistic Process

• Ammunition in chamber, trigger pulled, movement in the system:

  • Levers cause firing pin to come forward, impacting primer. Mechanical action initiating the firing sequence.

  • Primer explodes, jets of hot material through flash hole to propellant. Ignition of the propellant.

  • Propellant burns, gas production, pressure builds. Rapid combustion and pressure increase.

  • Bullet goes down the barrel. Projectile acceleration.

• Self-loading mechanism: ejects cartridge, loads next one. Automated reloading process.

Three Major Phases of Internal Ballistics

• Lock time, ignition time, barrel time.

Lock Time

• Lock time: time between activation of firing mechanism (trigger pull or electromagnetic activation) and ignition of the primer charge. The delay between trigger action and primer ignition.

• Movement from trigger pull to movement of firing pin assembly to impacting the base of the cartridge case. Mechanical sequence of events.

• Dependent on the trigger mechanism and its translation of motion. Trigger design influences lock time.

• Trigger mechanism: mechanical system, tight tolerances.

  • Changing curvature of levered surfaces changes sensitivity. Precision engineering affects trigger sensitivity.

• Trigger pull sensitivity depends on the intended use of the firearm, can range from hair trigger to very heavy trigger. Variable trigger weights for different applications.

• Trigger mechanism consists of levers (sears) that hold the firing pin or hammer under spring pressure until the trigger is operated. Mechanical components of the trigger system.

• Electromagnetic or electrical triggers operate differently. Alternative trigger designs.

• Safety didn't work is commonly alleged in accidental shootings. Safety mechanism failure is a common claim.

• Firing pin spring is compressed and held by a sear; pulling the trigger releases it, activating the primer. Spring compression and sear release.

• Most modern firearms have multiple safety mechanisms (drop safeties). Redundancy in safety features.

• Most common failure: operator. Human error is a prevalent cause of accidents.

Trigger Safety

• Physically blocks pulling the trigger. Simple mechanical obstruction.

• Simple push-across button. Basic safety design.

• May flick on automatically after the shot or require manual activation. Safety reset mechanisms.

• Blocks trigger movement, but internal mechanism is still free to move. Limited protection.

Sear Safety

• Mechanical safety that blocks one or more of the trigger sears. More comprehensive safety mechanism.

• More reliable than trigger safety. Enhanced reliability.

• If the direct attachment between the sear/safety and the firing pin is damaged, the firing pin can still go. Potential failure point.

• Includes grip safeties (safety button in grip). Need to hold the grip to compress the button and allow things to function. Requires grip engagement for operation.

• Different types of firearms have different structures and numbers of sears. Variation in sear configurations.

• Need to be able to recognize some of the key components on a technical diagram. Familiarity with firearm schematics.

• Grip safety: Is a type of sear safety (interacts with levers that release the firing pin). Specific type of sear safety.

• All sears are going to revolve over time and eventually get to a point where they become dangerous. Components degradation.

• It is the owner's responsibility to judge when the sears are feeling too light and get some of the internal pieces replaced or refurbished or take them to a gunsmith to have it looked at. Maintenance is essential.

• Firearms should be regularly maintained so that a qualified gunsmith can rebuild them. Professional maintenance is recommended.