Re: Primers?
Start at 23.5 and load several at that charge weight and then move up two or three tenths of a grain at a time till you reach the load you are trying to reach or the maximum load listed. (25.5) Fire all three of the rounds starting at the lowest and check each one as you shoot them.
Look for flattened or bulging primers, stamping marks of the bolt face in the head of the case, a rim around the firing pin dent in the primer where brass has flowed into the firing pin opening of the bolt face, look for a bright ring on the side of the case where the head ends and the case wall begins. check for gas leaks around the primer and cracks around the neck and shoulder area. You can do a search on pressure signs and come up with more. If you do see any signs of pressure reduce down to a tenth to go any further or better yet, stop there.
Another good thing to do would be to get a good reloading manual that shows pictures of pressure signs such as The ABC's of Reloading so you can see exactly what you are looking for.
Be safe!