Hand Lapping is a manual process that deposits lead evenly into the bore of a barrel. The primary goal of Hand Lapping is to smooth out the bore as much as possible because a smooth bore results in a more accurate barrel. Hand Lapping essentially eliminates the break-in process of a new barrel.
Melonite is a surface conversion treatment that in effect changes the molecular structure of steel thereby making it extremely hard which results in a much longer lasting barrel life. Barrels that undergo the Meloniting treatment must have the barrel extensions specifically secured otherwise the process will loosen the extension. We always Melonite both the barrel and barrel extension together so the chamber and bore share the same consistency. **Never ever try to alter a Melonited barrel.
Twist rate refers to the how much distance a bullet has to travel down a barrel before completing one full rotation. For example, a barrel with 1/8 twist rate provides 1 full bullet rotation every 8 inches of travel down the barrel. Twist rates impact accuracy as well as pinpointing the most effective grain (weight and or length) of bullet a shooter will choose. Standard AR15 (.223 or 5.56 Nato) twist rates are 1/7, 1/8 and 1/9. The lower the twist rate, the more suited a barrel will be for a heavier grain bullet. A higher twist rate, indicates the barrel will be more suited for a lighter grain bullet. AR10(.308) rifles typically come with either 1/10 or 1/11 twist rates.
Dwell time is a term that pertains to time, distance and pressure as a bullet leaves the chamber, travels past the gas port and exits the barrel. Dwell time is affected by the powder used in ammunition in addition to the length of the gas system and the total length of a barrel. In the case of AR type rifles, proper dwell time affects reliable cycling in addition to speed of cycling.
AR15 Gas Length refers to the length of the gas tube or to be more specific, the length from the gas key of the bolt carrier to the gas port in the barrel. The most common lengths for gas systems are: Pistol Length(the shortest), Carbine Length, Mid Length and Rifle Length(the longest). The intermediate length gas system is approximately 2" longer than mid length and 1.5" shorter than rifle length. In theory, the longer the gas system, the softer shooting the weapon. Gas length is impacted by the barrel length and subsequent dwell time limitations.
Cerakote is a ceramic coating used to protect and decorate metals. It is an extremely effective coating for metal parts that are subject to heat or friction. There are two ways to apply Cerakote; time cured and heat cured. The majority of firearm applications are completed with the heat cured process.
Head spacing is a term that refers to the chamber seating of a bullet. It's always a good idea to use a go/no go gauge when building a firearm. That said, rarely is a weapon out of spec if built around a barrel that has a properly seated/indexed barrel extension and utilization of a milspec or better bolt.
Barrel nut torque affects barrel accuracy. Tests have shown that a barrel nut torqued at 70lbs or higher creates enough stability to keep your weapon accurate. Be wary of barrel nuts that don't deliver enough torque. There are always exceptions to the rules but physics is physics.
Free float refers to a barrel that is not contacted by the hand guard. **Please note that as hand guards become more and more low profile, the higher risk of your gas block or gas block screws contacting the inside of your hand guard. Always make sure no part of the gas block ever touches the hand guard.
Longitudinal flexing or barrel whip refers to the flexing of a barrel when the weapon is fired. Barrel mass, geometry and heat play a significant part of flex. The less flex, the more accurate the barrel especially for follow-up shots or when the barrel is fired when hot.
Are you lucky? Preparation meeting opportunity is the best definition of luck. Prepare for whatever it is you do so when you have an opportunity to shine, you will. Just keep in mind that some less capable individuals may shrug off your accomplishment as luck...