We present calculations of multiphoton ionization of inert gases using an improved version of the R-matrix Floquet method. We use a new radial basis for the R–matrix internal region which avoids the use of non-variational corrections to the calculated R-matrix. This provides the freedom to choose either the length or velocity gauge to describe the laser–atom interaction in this region. Differences between results calculated using length and velocity gauges are discussed. We present new results for argon at 248 nm, the fundamental mode of the KrF laser.