Regulating seating depth and the resulting "jump" to the rifling is widely regarded as fundamental to improved accuracy. A few thousandths of an inch change between the bullet and the rifling can make the difference between average accuracy and real tack‑driver performance.

The Lock‑N‑Load® O.A.L. Gauge is universally acclaimed as the most accurate, easy‑to‑use and reliable method of regulating seating depth and the resulting "jump" to the rifling.

Straight Model

Item #C1000

For all bolt‑action and single‑shot firearms, or any firearm with straight‑line access to the chamber. This model is preferred, as it is most precise and user friendly.

Curved Model

Item #C1550

For all autoloader, lever‑action, or pump‑action rifles. Also fits all bolt‑action and single‑shot firearms. Inserts into chamber through ejection port. Not compatible with Adapter "D" or short‑bodied cases.

Achieve precise bullet seating depth.

To use the Lock‑N‑Load® O.A.L. Gauge, you will need a Modified Case (sold separately) to fit your firearm's chamber and thread it onto the gauge. These specially prepared modified cases are threaded at the case‑head and have a .002" oversized neck to accept the same bullets you intend to load.

This is critical, as the Lock‑N‑Load® O.A.L. Gauge dimensions obtained will be accurate to .001". These results cannot be attained with competitive products, which use a simulated bullet with an arbitrary shape.