(This is probably more information than you need for your simple question, but someone else might like the information)

Compiled Service Records on microfilm are available for purchase (not rent – unless something has changed since I last looked) from NARA. Depending on whether you want USA or CSA records determine the number of microfilms per Regiment. (Confederates tend to have much less information, therefore, fewer microfilms.)
Example: There are 193 total microfilm rolls for the Compiled Service Records of the Confederate soldiers belonging to units from the State of Missouri. There are 854 total microfilm rolls for the Compiled Service records of the Union Soldiers belonging to units from the State of Missouri. There are usually about two letters (i.e.: A-B) per each roll, so each Regiment would have an average of 13 rolls. CSA could be anywhere from just a small part of a microfilm roll to several microfilm rolls.

I don’t remember the cost per roll from NARA, but I think it is somewhere around the $60 each range. You can check their site for prices. I think someone posted a NARA microfilm rate increase on this message board a couple of years ago. I got some before the increase.

Some major libraries may have them on site. I know the Missouri State Historical Society at Columbia (MSHS-C) has the complete Missouri rolls (both CSA and USA). I think one of the public libraries in St. Louis also has copies. (The Missouri State Historical Society at St Louis does not have them, the last time I checked)

At the MSHA-C, there are four different sets of microfilms to review:
1) Index – which just lists the soldiers alphabetically and what Regiment they were with (a waste of time if you already know the name and regiment)
2) Descriptive Cards – another alphabetical listing of the soldiers but the microfilm rolls shows the descriptive card (I think these might be by Regiment)
3) Actual Service Record Cards – By Regiment, alphabetical order. These will give the bi-monthly muster cards and other items SOMETIMES such as casualty sheets, enlistment papers, prison records, etc
4) Mics Papers – These are odds and ends they found and didn’t know what to do with them – in alphabetical order. I have found very few items for folks I was looking for in this set.

Keep in mind that there Compiled Service Records are transcriptions from the original bi-monthly muster rolls and other items they tossed together for pension purposes after the war. They are sometimes incomplete and errors do exist.

I have downloaded a copy of the lists of microfilms at NARA for the Union Missouri Regiment and the Missouri Confederate Regiments (PDF’s). Email me and I will send you a copy. I found the NARA site a little hard to navigate.

If you look at the beginning of the first roll of the microfilm for each Regiment (i.e.: A-B), it also includes the Event Records for each Company of that Regiment. These Event Records were things that happened to a each Company during the two-month muster roll. Depending on the person writing the information down, it could be anywhere from nothing to very detailed, from miles marched, to places camped, to who was wounded or killed. These Event Records were located on the second page of the original bi-monthly muster roll. They are also published in the Supplement to the ‘Official Records’. (There are also separate microfilm rolls for these Event Records, with several Regiments per microfilm roll)

And to let you know, the Missouri State Archives at Jefferson City (MSA-JC) has the original bi-monthly muster rolls (from where the Compiled Service Records were transcribed). They tend to have all of the USA Missouri Regiments and a few of the CSA Missouri Regiments. You can order a microfilm of these bi-monthly records from MSA-JC for about $15 a roll. They tend to be pretty hard to read due to the age and condition of the muster rolls. I do not have a listing of the microfilm rolls available at MSA-JC.

The Compiled Service Records are on 16mm microfilm and the original bi-monthly muster rolls are on 32mm microfilm.

If anyone has actually read this far down and knows that these microfilm rolls can be borrowed or rented, or other libraries that have copies, please let me know.

Craig