Good source of information on driving band types and uses is the D 460 Geschossrigbuch
There are 5 main types of driving bands listed in this document:
Copper (Kupfer) it is the best material from mechanical properties standpoint. Copper is however relatively scarce. It also sticks to the barrel wall and can build up there. Decoppering wire is used to prevent this.
KPS bands - Copper is plated over soft steel. Some copper is saved but the manufacture is delicate because the two metals have to be bonded perfectly.
Weicheisen - they are FES bands IMHO.
FES bands - sintered soft iron. Manufacture process is quite complicated but the iron is plentifull. The barrel wear is higher, it can be compensated by using “colder” powders.
FEW bands are made from pure soft iron (carbon content only about 0,015%). the bands were not pressed into the groove on the projectile body as a ring, but were hammered as a strip, resulting in 1-2mm gap on the driving band. Bands had to be protected against corrosion.
You can see that the same projectile used more band types for example F.H.Gr. (105mm) Ausf. A - Copper, Ausf B - KPS, Ausf. C - FES.
Another source can be the D97 which lists the catalogue numbers for military materiel and has driving band section 13-26, there you can see that there are no Weicheisen only FES bands for the calibers that list Weicheisen in D 460.
Another reliable but tedious method is to go thru all manuals HDv 119 and HDv 481 and see what ammo is listed. For example
H.Dv.119/511 Schußtafel für die schwere Feldhaubitze 18 lists these rounds:
15cm Granate 19
15cm Granate 19 FES
15cm Granate 19 Stahlguß
15cm Granate 19 Stahlguß FES
15cm Granate 19 Beton (Anhang 2)
15cm Granate 19 Nebel (Anhang 3)
15cm Granate 36
15cm Granate 36 FES
15cm Granate 36 FEW
15cm Granate 38 Nebel (Anhang 4)
15cm Granate 39 Hl/A (Anhang 5)
So not only “Beute” ammunition used FEW bands, German 15 and 17 cm FEW ammo is quite common.