This is actually a topic on another forum, but I wanted to find out any info I can on it. I have a p99 date code AC. I do have a notch on my block, but have seen others that do not. Was there a change midway through production? The link to the thread on the other forum is
http://www.parkcitiestactical.com/ubb....=000234
http://www.parkcitiestactical.com/ubb....=000234