The following list of the artillery at Champion Hill is taken from the 3 volumes of Ed Bearss, The Vicksburg Campaign, (1986). Bearss draws heavily from the ORs so I expect he has included whatever information can be found from that source.
Confederate
Loring's Division
C, 14th Mississippi Artillery Battalion – 2 x 6# SB, 2 x 12# How
G, 1st Mississippi Light Artillery Regiment – 6 guns
A and C, Pointe Coupée (Louisiana) Artillery – 8 guns including 2 x 3" R, 2 x 6# SB, 2 x 12# How (no indication as to the last two guns)
D, 1st Mississippi Light Artillery Regiment – 4 guns
Stevenson's Division
Botetourt (Virginia) Artillery – 1x 12# Nap, 1 x 6# SB (lost two guns earlier in the campaign)
A, 1st Mississippi Light Artillery Regiment – 2 x 12# Nap, 2 x 6# SB
Cherokee (Georgia) Artillery – 4 x 10# Parrott R
Waddell's Alabama Battery – 2 x 6# SB, 2 x 12# How, 2x 12# Nap
3rd Maryland Artillery – 2 x 3" R, 4 x 6# SB
Bowen's Divison
Wade's (Missouri) Battery – 6 guns including 3 x 10# Parrott R
Landis' (Missouri) Battery – 2 x 12# Nap, 2 x 24# How
Guibor's (Missouri) Battery – 4 x 12# Nap
3rd Missouri Battery – 4 guns including 2 x 24# How
Lowe's (Missouri) Battery – 4 guns
Union
Osterhaus' Division
7th Battery, Michigan Light Artillery – 6 x 10# Parrott R
1st Battery, Wisconsin Light Artillery – 6 x 20# Parrott R
Smith's Division
Chicago Mercantile Battery, Illinois Light Artillery – 2 x 3" R, 4 x 6# SB
17th Battery, Ohio Light Artillery – 6 x 10# Parrott R
Hovey's Division
2nd Battery, Ohio Light Artillery – 6 guns
16th Battery, Ohio Light Artillery – 6 guns
A, 1st Missouri Light Artillery – 6 x 6# SB
Carr's Division
A, 2nd Illinois Light Artillery – 2 6# SB, 2x 10# Parrott R
1st Battery, Indiana Light Artillery – 2 x 12# How, 4 x 12# Nap
Blair's Division
A, 1st Illinois Light Artillery -1 x 10# Parrott R, 5 x 12# How
B, 1st Illinois Light Artillery – 2 x 12# How, 4x 6# SB
Logan's Division
D, 1st Illinois Light Artillery – 4 x 24# How
L, 2nd Illinois Light Artillery – 4 x 12# James R
8th Battery, Michigan Light Artillery – 2 x 12# How, 4 x 12# James R
3rd Battery, Ohio Light Artillery – 2 x 6# SB, 4 x 12# James R
Crocker's Division
M, 1st Missouri Light Artillery – 6 x 10# Parrott R
11th Battery, Ohio Light Artillery – 6 guns
6th Battery, Wisconsin Light Artillery – 6 guns including 12# How
12th Battery, Wisconsin Light Artillery – 4 guns