Handheld radios talking line-of-sight with no obstacles will communicate approx. 2 miles. When talking from inside a building to outside, you can expect 1/4 to 1/2 miles range. Holding the antenna perpendicular to the ground gives you the best range. Height and placement of the antenna determines range. If you were on a mountain you could talk many miles into the valley below. However, in real world applications, range is limited. It can even be limited by the body fluid of the person wearing the radio on their hip, or blocked somewhat by the metal of the automobile one is riding in.
Channels 18-22 are listed as GMRS channels and may have more power than 1-17. The FRS channels are limited to 1/2 watt. But don't be fooled wattage doesn't equal distance. Higher wattage may give you a little more distance, but mostly it will give you clarity in the fringe areas.
Here is a link to the user guide: http://www.motorola.com/web/Business/Products/ConsumerTwo-WayRadios/Talkabout-MJ270R-Two-Way-Radio/_Documents/MJ270.pdf
A link to Motorola's page about the radio: http://www.motorola.com/Business/US-EN/Business+Product+and+Services/Two-Way+Radios+-+Consumers/MJ270R_Talkabout_Two-Way-Radio_B2B_US-EN
And I see where they are quoting 27 miles*, and go on to say:
*How far can I expect my radios to communicate? The communication range quoted is calculated under optimum conditions, with an unobstructed line of sight. Actual range will vary depending on terrain and conditions, and is often less than the maximum possible. Your actual range will be limited by several factors including, but not limited to, terrain, weather conditions, electromagnetic interference and obstructions.
Unfortunately, we are seldom in idea conditions. Radio-to-radio is going to get you 1/4 mile to 2 miles in real conditions.
thanks i dont usually use walkie talkies