HomeEditor's BlogMiller Precision Arms: Customize your first and only 300 Win Mag on a true AR platform like Jesse James! Miller Precision Arms: Customize your first and only 300 Win Mag on a true AR platform like Jesse James! By AmSJ Staff 2014 Editor's Blog, Firearms Industry Showcase 0 Comments Jesse James with his new 300! Go to shopmillerprecisionarms.com to custom build your own MPA300 Guardian and see why Jesse James prefers them over others. Like them on Facebook here and follow them on Twitter here. Related Posts A New Year, New Editor – Welcome Danielle Breteau The Growing Trend of Women Owning Firearms Is it better to stand in a Weaver or Isoceles Stances? About Author AmSJ Staff Add a Comment Cancel replyYour email address will not be published. Required fields are marked *Comment:*Name:* Email Address:* Website: Save my name, email, and website in this browser for the next time I comment.