This was posted on the DNR website and it explains the reasoning behind the hpr proposal...
The DNR believes this change can be made at this time for the following reasons: There are currently no limits on rifles that are legal to use for species other than migratory birds, deer, and wild turkey. Muzzleloaders have evolved to the point that with smokeless powder (which is legal to use), they are essentially a high-powered rifle (accurate 500 yard gun). They are legal in several nearby states, including Kentucky, Michigan (the northern part of the state), and Pennsylvania. There has not been an increase in hunting-related accidents as the result of the use of rifles, both in Indiana and in several other states where they are allowed. There isn’t a need to limit the equipment that can be used to take deer in order to manage the deer herd. The deer harvest was a record in 2012, and the DNR is managing the deer herd through other means. Rifle cartridges that fire a bullet at least .243 in diameter and have a minimum case length of 1.16 inches long can safely and humanely kill white-tailed deer.
