Accuracy of a relativistic weak-coupling expansion procedure for solving the Hamiltonian bound-state eigenvalue problem in theories with asymptotic freedom is measured using a well-known matrix model. The model is exactly soluble and simple enough to study the method up to sixth order in the expansion. The procedure is found in this case to match the precision of the best available benchmark method of the altered Wegner flow equation, reaching the accuracy of a few percent.

PACS numbers: 11.10.Gh, 11.10.Ef