4th I tried the same Peregrine 286gr expanding copper monolithic with a different, slower burning powder, S361. I was hoping to achieve lower pressures with the same velocities, and perhaps horizontally closer groups. The results were not what I was expecting!!! Each barrel produced a lovely group, but velocitys were low and the groups were vertically very far apart. With lessons learnt from the highland bullets (increased velocity moved the bottom barrels group up), I thought I could move the two groups closer together. Horizontally they were closer then I had previously attained. However, when I increased the load by 2gr, there was hardly any difference in velocity, but the action got difficult to open! Fearing high pressures I will not procede any further with this S361 (slow burning powder). Bearing in mind I got 2200f/s from the same bullet with S335 before the action got sticky, but with S361 it was difficult to open at just 1970f/s... If anyone is able to explain how that works to me, please do, I'd love to under stand how the increase in powder from 63gr to 65gr (which is the recommended starting load in Peregrins reloading manual) caused no increase in velocity but a noticeable increase in sticky action/ presure...???
