GA Store

The Official GAP Merchandise

Apparel, Outdoors, Survival and more

  1. Home
  2. JGS 6mm GT Reamer and Go-Gauge

JGS 6mm GT Reamer and Go-Gauge


The 6mm GT is a new cartridge design from George Gardner (owner, GA Precision) and Tom Jacobs (owner, Vapor Trail Valley Bullets) that optimizes cartridge dimensions for low SD's and extremely consistent performance both on the bench and in practical precision application (PRS style competitions). 

  • 35 degree shoulder for trouble-free feeding, specifically with detachable magazine systems. 
  • No magazine inserts or modifications required; just use standard out-of-box 308 Win. AICS or AW magazines. 
  • Optimal case efficiency nearing 100% volume usage @ 33-35 grains of Varget. 
  • 3020-3100 fps with 103-105 grain bullets or approximately 3000 fps with 115's.
this reamer and hs gauge mfg by JGS Precision. 


  • Dies on order with Redding,  and are due in Summer, 2019.
  • RCBS Matchmaster FL bushing and Hornady FL non-bushing are available through GAP now. 
  • Brass is being produced by Alpha Munitions in production for early Fall 2019
  • typical powder to be used: Hodgedon Varget or H4895