Two years ago, Winchester introduced its Ballistics Calculator at Winchester.com, following with apps for iPhone and iPod Touch. Now the app has been updated to make the calculations more comprehensive. The original app allowed users to choose centerfire rifle ammunition and compare different cartridges with charts and graphs. The updated version now helps users discover aiming points, impact points, and trajectories for rimfire, shotgun, slug, and handgun hunting ammunition. “We listened to the great feedback, and now the Ballistics Calculator is improved,” said Brett Flaugher, Winchester Ammunition’s vice president of marketing and sales.