This website will tell you everything you need to know about AR-15 rifles, carbines and pistols. You can click on the model description of each gun, and a list will display on your screen.
In this list you will be able to find data related to the chamber, the twist rate, the barrel, the bore and the muzzle of the weapon (among many other characteristics). Every model is tagged with a price. However, not everybody is allowed to order weapons. You need to have a “dealers account” if you want to purchase any of these items. The Armed Forces have military discounts when purchasing these weapons, because Olympic Arms is very supportive of them. Every arm you purchase is covered with warranty (the terms are explained in detail in the website). Olympic Arms goal is to become the leader of the industry, and in order to achieve that, they believe they need to have an excellent customer service department, and a high range of satisfaction among customers. 
