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.
Difference Between CDROM and DVD. DVDs and CDROMs are both optical storage devices that have a lot of use; the most prominent of which is the distribution of content like movies, music, software, and such. The biggest difference between a CDROM and a DVD is their capacity. A CDROM typically holds 700MB of data per disc while a DVD can hold 4.7GB on a single layer. Dual layer and double-sided DVD discs push this to a maximum of 17GB. This is also the main reason why the CDROM was superseded by the DVD. Another advantage of a DVD is its much faster data transfer speeds.