Browning BT-99 Owners Manual - Page 26

Available 12 Gauge Invector-Plus™ tubes: RIM NOTCHES X on side of tube I II III IIII IIIII No notches CHOKE DESIGNATION WITH LEAD X-Full Special Full Improved Modified Modified Improved Cylinder Skeet Cylinder CHOKE DESIGNATION WITH STEEL * ** Full Improved Modified Modified Improved Cylinder Cylinder The words INVECTOR-PLUS mean your shotgun uses the Invector-Plus choke tube system designed for use in Browning 12 gauge shotguns with back-bored barrels. The extra length, combined with special tube tapers, gives the finest possible patterns for target shooters. Plus, you retain the same choke switching convenience of the Standard Invector system. Invector choke tubes are all fully steel and lead shot compatible. A special choke tube wrench is provided to remove and tighten these tubes. CAUTION: Invector-Plus tubes are for use in Browning shotguns with Browning back-bored barrels only (.745" + 0 - .005), and are not interchangeable with 12 gauge Standard Invector choke tubes. Do not use Invector-Plus tubes in barrels threaded for Standard Invector tubes. Do not use Standard Invector tubes in barrels threaded for Invector-Plus tubes. Failure to follow these warnings may cause damage to your gun and cause injury to yourself and others. NOTE: If your BT-99 has Standard Invector or Invector-Plus choke tubes, carefully adhere to the following instructions. DO NOT FIRE THIS SHOTGUN WITHOUT HAVING AN INVECTOR CHOKE TUBE INSTALLED. PERMANENT DAMAGE MAY RESULT TO THE THREADS INSIDE THE BARREL. 25