I like the M1 style over the covered target style turrets. The dust caps seem to always be on when you need to dial. And with some of the older dogs they might not give you enough time to fuss with the dust caps.
I don't know what your budget is but did you look into the Swarovski Habicht line of scopes? They have a front adj. The Nightforce bench rest is also front adjust but the magnification is fairly high.