The Boliden Mineral Aitik mine has worked to increase the through-put in the primary AG mills together with Swebrec. A raised specific charge from 0.9 to 1.3 kg/m3 raised the throughput by nearly 7%. This was implemented in 2009. For two rounds Swebrec has mapped joints from 3D images to determine the rock mass factor and combined Split Desktop measurements with sieving of muck-pile samples to get the sieving curve of the muck pile, based on the Swebrec function. For a 3rd round such curves were fed into a crusher model and results compared with Online data. The crusher product can affect the mills by three mechanisms; a harder blasting that i) produces more fines that may pass the mill intact, ii) gives a finer crusher product which takes a shorter time to grind iii) increases the amount of larger stones that pass the crusher intact but have an increased grindability. All three must contribute to the increased mill through-put.