Any rifle with a tight chamber is going to suffer with out-of-spec ammunition, and most operational failures in self-loading rifles can be traced back to this problem. If you're a reloader, you know this better than most. Unlike other gauges available, the precision JP Case Gauge is cut with an actual match chamber finish reamer so it not only checks head space but also case diameter relative to typical match-grade chambers and min/max case length on top of that. What's more, the fact is that most other gauges indicate minimum and maximum case headspace as defined by SAAMI, which still allows for a possible interference between a maximum-sized cartridge and a minimum allowable chamber. While this would not be an issue in a bolt gun, it will bring everything to a stop in a self-loader. Our gauge insures that the maximum cartridge indicated by the gage is still within the minimum SAAMI allowable chamber. In other words, if your ammunition passes our gauge, it absolutely will fit the chamber. It's the only sure way to know that your ammo is compatible. Availble in .223 and .308. Price is $39.95.