In a double, where two constrictions are available, improved cylinder and modified are a good pairing, especially in fixed-choke guns. If screw-in chokes are an option, try a more forgiving match, like skeet and light modified. Shoot the more open barrel first on the covey rise, then the tighter barrel as the birds make their escape.
The CD and DVD have a single track of data in the form of a spiral, which starts as the center going outwards. The data is stored on the bumps or pits which are then read by the CD/DVD layer. The bumps/pits on a DVD are much smaller than on CD, allowing the DVD to store more data.
DVD-R and DVD+R are two competing recordable DVD formats. DVD-R was introduced in 1997, and DVD+R arrived in 2002. The two formats are incompatible with each other. You can not burn DVD dash discs using DVD+ drives, and vice versa, although dual format burners are available. The developers DVD+R have positioned it as a format superior to DVD-R. The major difference is the addressing system, which refers to the way the laser finds the proper position for data to be written.