I would suggest a Wilson (or other brand) case headspace gauge. You will know instantly if your cases are prepped properly. I had some problems with my .308 AR reloads and discovered I wasn't setting the shoulder back enough. It was quite frankly a very small amount correction but eliminated the problems. After that, bought one for the .223 AR and even my .222 bolt rifle. It's simple in design and eliminates any case questions if you experience FTL's and such. Good luck!

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