
The RCBS .300 AAC Blackout Chamber Case Length Gauge (SKU: R88282) is a must-have tool for reloaders who want to ensure safe, reliable, and accurate ammo in this versatile calibre. Designed to quickly check both chamber dimensions and case length tolerances, this hardened steel gauge removes the guesswork from your reloading process.
Simply drop your resized or loaded .300 BLK cartridge into the gauge to confirm it meets SAAMI specs for headspace and overall case length. Ideal for both supersonic and subsonic reloads, this tool helps prevent feeding issues, overpressure problems, and inconsistent ignition — especially critical in semi-auto platforms like AR-15s or short-barrel setups.
Built tough to last a lifetime on the bench, RCBS precision gauges are trusted by serious reloaders worldwide and offer peace of mind when loading for hunting, competition, or tactical use.
SPECIFICATIONS
Calibre: .300 AAC Blackout
Function: Case length and chamber dimension check
Material: Hardened steel
Compatibility: Sized or loaded .300 Blackout ammo
Use: Confirms headspace, shoulder position & max case length
Part Number: R88282
Brand: RCBS
Country of Origin: USA