The AEP7 laser pistol was put into service to replace the AEP5 model. With a generous battery size, tight shot grouping at range, resilience to extended use, and fairly decent damage output, it is a very good choice for a sidearm and is used extensively in this role by the Brotherhood of Steel and the Enclave in the Capital Wasteland.
As the successor to the AEP5, it boasted a redesigned focusing crystal pattern, an improved photonic focusing chamber, and selectable laser focus, wavelength, pulse energy and repetition rate. In addition, it was lighter and less bulky than its predecessor and was perceived as a step toward replacing the N99 10mm pistol with a laser weapon as the standard issue sidearm for military forces.
The AEP7 was produced in large numbers, thanks to newly developed manufacturing technologies in the USA, although logistics and supply issues in pre-War USA, caused by its prolonged war with China, prevented its wide-scale deployment.
The weapon, like many other unique weapon variants, is visually identical to its common counterpart, in this case being the AEP7 laser pistol. It is fully automatic (unless you have the Broken Steeladd-on), and has a 30 round capacity. It is powered by easy to find energy cells, uses very few action points, but it can only be repaired manually.
Although it is marked as a quest item (previous to Broken Steel), the weapon can be used to repair another laser pistol to get it out of your inventory.
There is a glitch in the Operation: Anchorage DLC, where if you have Colonel Autumn's laser pistol and enter the simulation, then you will take the pistol with you. It cannot be removed during the simulation, and is still classed as a quest item. However, there are no energy cells in the simulation, so having this in your inventory is useless.
Similar to the above note, if the player has it when they enter The Pitt, they will keep it in their inventory. However, energy cells can be found in the steelyard, on destroyed protectrons.
If you want Colonel Autumn's uniform and his pistol, then it is recommended that you either resolve it peacefully and kill him from behind when he walks away, or position yourself between him and the purifier; it is not uncommon for him to fall into the water bellow the purifier, making it nearly impossible to loot him.
Without Broken Steel installed, this gun will be have no applicable purpose, due to the game ending soon after defeating Colonel Autumn.