Overall Length (OAL), is an important measurement for firearms &/or ammunition and refers to the total length of a loaded cartridge or the complete length of a firearm.
Most states have parameters around how long or short certain weapons can be. For example, the standard AR-15 rifle has a barrel length of 16” which is the minimum length for a rifle barrel.
If you attach a shorter barrel to your AR-15 without the proper paperwork and tax stamps in place, you are technically breaking the law!
To use a short barrel on a rifle platform you need to officially make it a Short Barreled Rifle, or SBR. This involves a $200 tax stamp.
The overall length of an ammunition cartridge is a measurement from the base of the brass or steel shell casing to the tip of the bullet, seated into the casing.
Cartridge overall length, sometimes shortened to "COL", is extremely important to the safe functioning of reloads in firearms.
See information below for a further look at Ammunition OAL and Firearm OAL
Ammunition OAL
Definition
OAL for ammunition refers to the length from the base of the cartridge case to the tip of the bullet.
Handloading/Reloading
For those who load their own ammunition, getting the correct OAL is critical. Too long, and the cartridge might not chamber properly or could affect pressure. Too short, and it might increase chamber pressure to dangerous levels.
Bullet Seating
The depth at which a bullet is seated in the cartridge case affects the OAL. Different bullets, even of the same weight and caliber, can have different shapes, which can influence the OAL.
Feeding and Function
Correct OAL ensures reliable feeding from a magazine into the chamber and proper function of the firearm.
Firearm OAL
Definition
For firearms, OAL refers to the total length of the gun, typically measured from the muzzle to the end of the buttstock or the furthest rearward point on pistols.
Legal Implications
Many jurisdictions have legal minimum lengths for certain types of firearms, especially regarding rifles and shotguns. Being below the minimum OAL can classify a firearm as a "short-barreled" weapon, which might be restricted or require special permits.
Storage and Transportation
Knowing the OAL of a firearm can be essential for storage solutions, travel cases, and ensuring safe and compliant transportation.
Safety and Compliance
Understanding and adhering to correct OAL, whether for loaded cartridges or firearms, is crucial for safety. Incorrect OAL in ammunition can lead to malfunctions or dangerous pressure spikes.
Compliance with legal OAL standards for firearms ensures that individuals avoid potential legal complications.
Summary / Saved Rounds
In summary, Overall Length (OAL) in the shooting sports world provides essential measurements that impact the safety, function, and legality of both ammunition and firearms.
Proper attention to OAL ensures optimal performance and adherence to regulations.
