How does the CORE15™/ Adam Arms Piston System Work.. How about a demo video?

Mil-Spec and Mil-Standard Explained

In the firearms industry you hear the term Mil-Spec thrown around quite a lot. Let’s talk for a minute about exactly what the term means. A specification is a standard to which the end user, in this case the US Military, wishes something to be made and held to. The primary reason for this is consistency and interchangeability. Within that realm, and for what the Military Standard covers, there still remain a vast span of places and areas to “tighten up” if you will.

Let’s take a look at a few of those places...

The barrel, the heart of the rifle, arguably needs to be the most consistent and well-tuned part of the rifle. The Military Standard here, for 14.5” and 20” M4 barrels,  requires consistency of .0010 from front to rear. Here at CORE15™, nothing less than .0003 will make it through our inspection process which is twice the Military standard in tolerance.  Indeed, that inspection process itself is tighter than what the military requires, which is a 10% inspection rate.  We inspect and test fire 100% of our barrels and in turn complete guns, no questions asked.

Beyond the barrel, in getting to the action, simply keeping within the guidelines of Mil-Spec conformity is not enough for us.  Going above and beyond, both in fitment, finish quality and internal parts, we do everything possible to take the AR-15 platform to the next level. This shows through in the accuracy, consistency and durability of our rifles. But don’t take our word for it. Find your nearest CORE15™ Authorized Dealer and see if you don’t agree.

Twist Rates Explained

One of the biggest single leaps in firearms technology came in the mid-16th century when it was discovered that imparting spin to a projectile greatly increased the accuracy and range. Ever since that time ballisticians and engineers alike have debated endlessly the merits of one twist rate over another for a given caliber, projectile, and distance.  Over the last 20 yrs, advancements in technology and production have given us unprecedented capability to fine tune our barrels and twist rates.

Thanks in large part to the work of those aforementioned intellectuals, there is very little mystery in choosing a twist rate for your next .223/5.56.  The single phrase to keep in mind is “the heavier the bullet, the faster the twist rate needs to be”.  For the all around shooter, a 1:7 or 1:8 twist rate will stabilize virtually all commercially available projectiles for the .223 and 5.56 NATO.  If you plan to do quite a bit of shooting with very light, fast projectiles (varmint hunters take note), moving to a 1:9 twist barrel would be an excellent idea.  For the majority of shooters to whom the .223 and 5.56 NATO bullet weights begin and end at 55 grains, any of the above will work wonderfully.  The one shooter that truly needs to take note of twist rate is the long range, heavy bullet enthusiast (64gr or heavier).  For that type of shooting, one of the faster twist rates are a must. 

While entire books have been written on nothing more than twist rates and the ensuing stabilization, we sincerely hope the above has taken some of the mystery out of selecting a twist rate for your next project. Keep in mind if the rifle you prefer is not listed with your ideal twist rate, we are happy to customize.  If you have further questions, please see your nearest Core 15 Authorized Dealer or contact us directly.

Polygonal Rifling Explained

Here is a chart showing several different types of rifling.

There are several advantages to polygonal rifling, these include: slight increase in muzzle velocity and accuracy, less bullet deformation resulting in a smoother projectile with less wind resistance, reduced copper or lead buildup making maintenance easier, and a slightly longer barrel life.

CORE15™ employs the use of Polygonal Rifling as well as other rifling styles in different models of our rifles.

Forged and Billet Explained

Forged

Our Receivers start off as impressions from a die referred to as closed die forging the aluminum is placed in a die resembling a mold, which is attached to the anvil. Usually the hammer die is shaped as well. The hammer is then dropped on the workpiece, causing the metal to flow and fill the die cavities. The hammer is generally in contact with the workpiece on the scale of milliseconds. Depending on the size and complexity of the part the hammer may be dropped multiple times in quick succession.

Billet

Bar stock, also colloquially known as billet, is a common form of raw purified metal, used to manufacture metal parts and products.
Most metal produced by a steel mill or aluminum plant is formed (via rolling or extrusion) into long continuous strips of various size and shape. These strips are cut at regular intervals and allowed to cool, each segment becoming a piece of bar stock. A good analogy is pasta-making, in which lumps of dough are extruded into various cross-sectional shapes (from simple bar or tube shapes, such as linguine or penne, to more elaborate extrusions, such as rotelle, fiori, or rotini); cut into lengths; and then dried in that form.

Both styles of Manufacturing give you high quality, durable components, all of our receivers are made from 7075 T-6 Aluminum.