Militaries worldwide have been using wood to protect the barrel for as long as shoulder arms have been in use. Wood was cheap, barrels were expensive.
What we know of today as a Mannlicher stock has its roots in the cavalry version of the German Gew 88 "commission" rifle, circa 1890. These had full length stocks, metal forend tips and spatulate bolt handles. Mannlicher himself was part of the "coamission." A picture of this model is below:
In 1900, Mannlicher mated this action and stock with Schoenauer's rotary magazine, creating the dynasty of rifles that we still enjoy today. The first real production model, the 1903 carbine, was intended for Alpine hunting.
Mannlicher-Schoenauers, along with Sako, CZ and a few others, used heavy barrels that were not effected by stock pressure. Accuracy was, and still is, remarkable. Other companies, such as Ruger, use pencil thin ultra-light barrels that heat up quickly and begin stringing. In 30 years of collecting such carbines, the most unusual model was the Antonio Zoli 1900 made in Italy. While it had a full length stock, the barrel was free-floated.