I was working up some loads yesterday for the 7mm STW. I had made three loads with 67.7gr. RE-22 using winchester brass and 10 loads using the same charge but using Nikel Plated Remington brass. When seating the bullet I noticed that they were harder to seat in the Nikel Plated brass. Would this be a cause for concern? The charge is no more than a maximum load reading from a sierra handloading book.