Researching this particular rabbit hole has been really interesting. First, I have to give a huge thanks to the fine folks at Kronoskaf. Their site on the Seven Years War has been so much fun to go through. I have previously noted that I wanted to model a force based off of Frei-Infantrie Von Mayr. The campaign I am most interested in is the Prussian push into Bohemia. During this campaign, Von Mayr is given a larger command of close to 2000 men including 400 cavalry to destroy some Austrian magazines in Bohemia and then raid into the German Austrian Allies and prevent them from raising forces to aid the Austrian War effort.
The first item that I needed was a period map to understand the places that were listed in the sketchy reports that I could find. What I found was the Muller Map of Bohemia that predates the Seven Years War and was printed in 1723. What is attractive about this map is that it looks like it belongs in a Sharp Practice Campaign. It was one of the first systematic mapping efforts taken of the area. Thus it has potential for use of earlier wars as well. There is a nice PDF that gives information about the history of the map and other background info that might be useful. Another good source would be the 1st Military Mapping by the Austro-Hungarians that occured between 1764 to 1767. This was done after the war but still is close enough to get a good lay of the land.
With this map in hand, I set out to map out where the campaign happened. I am still attempting to gather resources and have pulled down several nice histories on line. One account has Von Mayr leading his Frie-Infantrie with another battalion of similar troops (Frei-Infanterie von Kalben) plus about 200 Hussars (2 sqns of Szekely Hussars). These were supported by five artillery pieces, four of which were light one pound weapons and the fifth was twelve pounder. They moved with a minimum of baggage. In a history of Fredrick the Great, von Mayr's force was described as "swift wild fellows, sharp of stroke."
What they largely faced were garrison troops and training groups being gathered to supply troops to the Austrian field army. They begin the campaign in late April 1757 in Charwatetz. Just days prior to this, von Mayr, had gotten some good press by seizing a castle from the Austrians. He covered himself in glory and became visible enough to be given this independent command.
Now Johann von Mayr was a bit of a character. He reads as if he was a generated character from Sharp Practice. He was an illegitimate son of Count Stella. In a biography of Baron von Steuben, it describes his early life, "His boyhood was passed amid scenes of debauchery and profligacy." By eighteen he was expelled from Vienna and was destitute. He entered the military as a band boy in Hungary and fought in a war with Turkey to climb the ranks to become a sergeant. Eventually he became an officer then moved to Bavaria as a soldier of fortune. Then on to Saxony where he ended up leaving service due to a duel fought with a brother officer. This brings him to the attention of Frederick the Great. He hires him to for a Frei-Infantry Regiment to operate as an independent unit to fight the Austrian pandoors and grenzers.
Yet, he really didn't get a chance to shine until teh capture of the Castle of Tetschen. In this operation he was under the command of General Zastrow. On April 25th, the general was shot through the head by an Austrian Pandoor and killed instantly. Within days, von Mayr was given his chance to lead and assigned to destroy one or more Austrain magazines in Bohemia including the one in Pilsen. He makes it to Pilsen by May 2nd and destroyed the magazine beforw turning west towards Nurnberg. Other sources say that Pilsen was reached on May 8th.
Map from the same place as link above.
I have the figures for my von Mayr force. I haven't figured out my Austrians yet.