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6/24/2013

AR Build Diary: Barrel

By Gabby

barrel profiles for AR15As with each of our AR parts, there are many options for the barrel of your gun. The first factor to consider is the profile or contour.
Lightweight Profile - thin all the way through

Mid weight or Government Profile - thick in the front but thin under the hand guard

Bull or Heavy weight Profile - exactly as it sounds

What must be considered is that weight gets worse the longer you are shooting but thin barrels may have less accuracy and a shorter service life. Add to that dilemma, that a longer barrel will automatically be heavier than a shorter one, but accuracy is improved with length. It has also been reasoned that a shorter barrels can be easier for shooters who need to move around in tight spaces.


14.5" government profile barrel with 2" compensator of ArmedCandy rifle
Legally, we can't forget that any barrel shorter than 16" is considered a "Short Barrel Rile" or SBR, and must be registered properly. For my preference, I wanted as short a barrel as possible and wanted that measurement to include the muzzle device. I went for a 14.5" barrel and made sure to order a 1.5"+ compensator. In order to stay legal, my gunsmith permanently pinned the compensator so that it could not be removed from the rifle.

Barrels are often advertised as 'chrome-lined" which has many benefits. Most important, is that chrome is nice and slick which is good for the inside of your barrel. Also, chrome is harder than steel, keeping your barrel from deforming and slowing the wearing out process. You may notice that listed with some of the information about barrels for sale is the "twist". Basically, this is the rate at which the rifling turns inside the barrel. Depending on the weight of the bullets you will be shooting, you may prefer a loser or tighter twist rate. For my .223 AR, I chose the 1:7 twist which is fine for heavy bullets and typical range ammo.

We will discuss gas systems in more detail tomorrow, but for now, remember that the length of the gas tube will align with the spot on the barrel where a hole has been drilled for the gas block to sit. When purchasing a barrel, the retailer will designate a barrel as a short, mid, or rifle length gas system, regardless of the length or profile of the barrel. Keep in mind, the longer the gas tube, the better.

head space measurement for AR15While some feel that AR parts have been standardized to the point of making double checking unnecessary, I see nothing wrong with being extra careful. This is why I made sure to have my barrel's head-space checked when building my upper with my gun smith. This check is down using a special set of gauges that make sure the bolt will not close and the barrel will not allow a casing to load too deeply inside the chamber. I'm not even sure that I have fully grasped this concept, yet, but when it comes too firearms, I don't think anyone can be too careful.

Read all of the AR Build Diary here

©2013 ArmedCandy,LLC

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