The Confederates were very mixed. I have access to some division and corps returns from the first half of 1864 that indicate many Confederate units had mixed shoulder arms, ranging from the ubiquitous Springfield and Enfield through Austrian, Belgian, and even Mississippi rifles to .69 caliber smoothbore muskets.
The returns don't cover the entire Army of Tennessee but do have a significant portion of it. Some of them only give gross figures for a division but some go down to regimental level.
I'm trying to get them extracted so I can depict on-hand strengths and the mix of weapons.
One example is from April 1864:
Finley's Florida Brigade, Bate's Division
1st & 3rd Fla [Cav] – 371 men on-hand with 51 .577 caliber, 41 .58 caliber, and 70 .69 caliber Belgian rifled muskets, and 172 .69 caliber percussion muskets (presumably smoothbores).
1st Fla Inf – 312 men on-hand with 90 .57 caliber, 105 .58 cal, 57 .69 caliber Belgian, 26 .69 caliber percussion.
6th Fla Inf – 246 men on-hand with 29 .577 caliber, 67 .58 caliber, 55 .69 caliber Belgian, and 106 .69 caliber percussion.
7th Fla Inf – 267 men on-hand with 176 .57 caliber, 55 .58 caliber, 40. 70 caliber British, and 5 .69 calliber Belgian.
But others, such as Strahl's Tennessee Brigade of Cheatham's Division (also Apr 1864) had only a single caliber weapon in each regiment:
4th Tenn Inf – 128 men on-hand with 123 .577 caliber
5th Tenn Inf – 139 men on-hand with 141 .577 caliber
19th Tenn Inf – 182 men on-hand with 174 .577 caliber
24th Tenn Inf – 185 men on-hand with 181 .577 caliber
31st Tenn Inf – 143 men on-hand with 133 .54 caliber Austrian
33rd Tenn Inf – 121 men on-hand with 101 .54 caliber Austrian
Hope this helps.
Jim