This increase might be far too low. There were lots of soldiers that were picked up in local recruiting efforts, for instance, with poor documentation. Low-ranking soldiers were often cannon-fodder back when battles were fought on open fields with ranked artillery. It was common for them to have to face grape-shot, and even chain-shot and bar-shot (more commonly used against naval ships). The CW was very messy and bloody.
I have a historian friend whose on-line name is related to this type of warfare and who has written numerous books on this subject. We can't dismiss the viciousness of the tactics used in the CW and say "that was in the past" because the use of such destructive shot was pervasive.
Please be advised that "buck and ball" was an acceptable load to use in CW muskets. Such a load was made up of a paper-wrapped cartridge using large musket balls (buck) along with smaller shot (balls). The intent was to cause as many wounds as possible, even if you didn't kill the enemy. If you could wound as many as possible and cause infections, you could tie up the enemy's support-systems. Our youngsters don't ever learn this stuff in their sanitized history studies. It's a shame, because perhaps we could drop support for some of the support for warring factions around the world. Things haven't changed much in 150 years...