The UIC-10A Features an adjustable gas block. Due to the various differences in ammunition and operating pressures, we suggest adjusting the gas block to your specific ammunition for maximum reliability.
The UIC-10A Extractor features two o-rings. We have found in testing that with some ammunition this is too much resistance for the extractor to overcome and catch the lip on the cartridge and close the action completely. We have now begun to remove this second o-ring to aid in overall reliability, especially in cold weather.