I agree that the barrel pictures seem to indicate fairly heavy rust. One land is completely rusted through which indicates the rest of the barrel at that level was likely pitted badly adding to the stress risers at the point of the rust attack. I would not be overly concerned about other spanish rifle barrels if treated correctly and kept within reasonable load levels. I do not load my Traditions Pursuit LT over 100gr. black powder equivalent charges which means with synthetics that generate higher velocity I reduce charges accordingly. You must keep aware of what your selected powder is capable of. I also agree if a bullet seats funny pull the charge and inspect. Forcing the bullet down is a bad thing. Continuous constant pressure is fine but a sharp increase in loading before seating on the bullet is not a good thing which is what I get with the 777 crud ring.