The Versatility of the AR15® - Beginners Review of the AR15

[Rattler]

The AR15: Unmatched Versatility
Author: Thomas A. Spithaler
All Rights Reserved 12-31-09


Author with his favorite home build, an Oly Arms Eliminator Custom.

With a dozen brand names or more currently on the market, the AR15 rifle is the current leader both in firearms sales, and performance in the field. With mainstream brand names such as Smith & Wesson and Remington now on board accenting the established brands such as Olympic Arms, Bushmaster, DPMS and more, the AR15 is not going away. Plain and simple, it is becoming popular and more mainstream by the day.

As a firearm, the AR15 is by far the most versatile platform in the world, period. This family of rifles can fire calibers from 22lr to 50 BMG. Between these extremes are literally dozens of commercially available calibers and perhaps hundreds more wildcats, with more coming out seemingly daily. The beauty of this range of calibers available to the shooter is that they all function on the same lower receiver.

As a survival tool, it is simply unmatched. When speaking of the firearm itself, the AR15 has outlived and outperformed a great number of designs (both military and civilian) that have competed against it directly for use in the field, or indirectly in the hearts of the consumer. It has been the versatility of the firearm, and the enthusiastic engineers that have provided such innovative configuration and design technology that have driven the market of the AR15 to unforeseen heights, unmatched by any other firearm ever.

Since designed by Gene Stoner in the late 1950’s the AR15 (the semi-automatic version of what became best known under its military designation the M16), has undergone much innovative changes. The core however, has remained the same. In what amounts to a grown man’s ‘erector set’, the AR15 lower receiver is the basis for everything that has grown up around it. Caliber and configuration variations allow this single platform to become just about whatever the end user wants it to be. This versatility allows the AR15 to fulfill just about any project or mission requirement we might throw in front of it. It truly is a firearm fit for just about any occasion.


Author firing the same carbine, now outfitted with a 6.8 Remington (spec-II chamber) with an Olympic Arms 16" Stainless steel fluted bull barre. Brass is flying, and in spite of it just firing 5.56, is functioning perfectly

Adaptability
I have owned all sorts of multi-barreled, multi-caliber firearms over the years. Switch the barrel, switch the slide, switch the cylinder etc. The ability to shoot several calibers from the same firearm is a bonus to us as shooters in many ways. First and foremost, it saves the consumer money. Being able to buy just a barrel, cylinder, or an upper receiver assembly (even though it may be a several hundred dollar purchase), always beats the alternative of having spend two to three times that on a completely new firearm just to fit a new and perhaps limited application or requirement. This has been the mind-set for generations because no viable alternative platform was available to give the consumers the versatility they craved. The advent of the AR has changed all that. Combining the AR lower receiver as the foundation, with the ingenuity of the today’s designing engineers (all the while being pushed by the AR’s very demanding ownership base); the perfect pairing has been accomplished.


Sampling Military 5.56x45 and 6.8 Remington from HSM

Major Component Groups
The AR15 is made up of two main components. These units are called the upper receiver assembly (top-half), and the lower receiver assembly (bottom-half). These two assemblies are held together by only two pins. In the front of the receivers is the front takedown pin, also called the ‘pivot pin’. In the aft of the lower, the rear takedown pin. On the AR15, all major pins are installed from the right side of the firearm, and are removed by pushing on the left side of the pins, pushing them out to the right (from the shooters perspective that is). Simple to remember.

To disassemble these two components, simply push the pins from the left side of the firearms, towards the right. Sometimes a plastic or brass punch may be required on some of the tighter fitting units. Keep in mind that these pins are ‘captured’, which means they have a mechanical pin that physically ‘captures’ or holds the pins in place on the lower receiver component so that these pins do not get lost. Do not push too hard, or hammer the pins out of the holes. This will damage your lower receiver and is an expensive proposition to repair if at all possible.


Author's enjoying a day at the range with Dad and their own AR's

Start with the rear takedown pin first. Push this out to the right, and then you can ‘shotgun’ the upper, tilting it forward, relieving pressure on the front pivot pin, loosening the fit between the upper and lower, allowing for a much easier removal of the front pivot pin. Once you have driven these two pins left to right, the upper receiver will pull right off the lower. This is the core to the versatility of the AR15.

Also, please keep this in mind. Although all major brand names in the AR15 market currently have their receivers manufactured to the military specifications with regards to dimensional fit, there are allowable tolerances on each part. What this means to the end user is that each and every upper receiver unit may not fit perfectly, or at all, on every lower receiver. The result of these allowable tolerances may be that even though you have two parts that are both perfectly within the allowable print dimensions (in “spec” as they say), some fitting may be required. “Drop-in” parts that have an identical perfect between all parts is a myth. Obviously, if the fit is way off, please consult the vendor or manufacturer of the part for clarification before you go filing and grinding on your firearm. Ask first, modify only after manufacturers approval.


Author's main battle rifle top, with a collection of alternative caliber uppers. L-R:5.56 Varmint Upper
16” bull bbl. Upper in 6.8 Remington
16” lightweight upper in 5.56
16” 300 Fireball upper
20” 25 Winchester Super Short Mag upper
16” bull bbl upper in 7.62x39


One Lower: Many Applications
For the purposes of this article I have assembled a variety of different configuration and caliber upper receiver units for the AR15. What needs to be repeated and made clear in order that everyone understands the true versatility of the AR15, is that each of these configurations and calibers, all fit and function on the same lower receiver unit! Just by driving out these two pins, you can swap between calibers and configurations in seconds. See the fitting caveat in the previous paragraph.

Standard AR15 uppers are typically (or perhaps better said as ‘most popularly’) chambered in 5.56 x 45. This is the military 5.56 NATO cartridge that offers higher pressures and velocities than the civilian .223 Remington round. Keep in mind that while these two cartridges are similar, they are not identical. While AR’s chambered in the 5.56 round can shoot the civilian .223 Remington without concern, visa-versa is not recommended. Never fire a 5.56 cartridge in a firearm chambered specifically for .223 Remington. The chamberings are different, and with the increased pressures and longer leade requirements of the 5.56 round, it could cause disastrous results. For more details a quick internet search will net you quality articles defining the differences more clearly and in more detail that I have room for here.

The AR15 Pistol
As described so aptly in the previous issue of Survival Quarterly by Editor Ron Hood, the AR15 can be made as a pistol. If manufactured as, or originally registered and assembled as a pistol, your lower can be used convertibly either way as a rifle or pistol. If originally purchased as a rifle, it must stay a rifle unless otherwise registered through proper channels as a Short barreled rifle. Since this was covered so well in the last issue, I will not spend too much time on it here. I’ll simply remind the readers that AR15 pistols make excellent little bundles of firepower that should be consider for duty as a survival firearm, or entry weapon for LE and military use.

Home Defense Rifle
As an example, my main battle/home defense AR is in fact chambered in 5.56 x 45. This upper receiver is home assembled using parts from a variety of manufacturers. Configurations like this are offered by both Olympic Arms (The K7 Eliminator) and Bushmaster (The Dissipater) as a factory assembled rifle. This configuration offers a set-up where in the barrel is only 16”, but the sight radius is the same as a 20” barreled upper. To me, this offers the best of both worlds in that it is compact and lighter weight like a carbine, and yet handles and acquires a quicker, more accurate sight pictures like that of a full size 20” rifle. For home defense, with the proper ammunition, this is an excellent choice.

Varmint/Predator/Small Game
When it comes to doing other jobs in addition to the staple home defense role, this is where the AR15 is in a class by itself. For pure small game, squirrel, rabbit etc, take a look at the 22 lr kits out there. Some are drop in bolt carrier assemblies, while other brand names offer complete dedicated uppers. Quick pointing, accurate, and inexpensive to shoot, if you’re not hunting with a 22 conversion, they have become popular training alternatives for law enforcement and military alike, when budgets do not allow for the ever increasing cost of 5.56 ammo.

As a varmint or predator hunter, calibers like 17 Remington, 204 Ruger, and 222 and 223 Remington might be great options. Smaller caliber, higher velocity rounds where preservation of game meat is not the primary goal, but rather a quick dispatch of the game in a manner that will also protect the hide bode well in this territory.

Whitetail/Mule Deer/Medium Game
When looking at other caliber options, the AR is ready for action against just about any North American big game. The 6.8 Remington (now on its third incarnation of approved chambering; Spec-I, Spec-II, and the newest 6.8 x 43) and venerable 7.62x39 make excellent choices for deer, and ammunition is readily available from a variety of commercial loaders. Alexander Arms manufactures an AR chambered in their 6.5 Grendel caliber that also offers a great ballistics option. While this caliber has some very serious followers, it is not without its own idiosyncrasies, and this author simply feels there are better cartridges available. Bushmaster produces a 450 Bushmaster caliber that smacks a 300 grain bullet at 1800+ fps. Very hard hitting and effective, but not a long range cartridge.


Loading a 10 round AR15 magazine for firing 7.62x39 caliber ammunition.

Remington introduced the 30 Remington AR in late 2008 touting ballistics slightly better than a .308 Remington. With the .308 being the ‘standard’ if you will for whitetail hunters, better ballistics than that are the minimum requirement to have any new hunting cartridge be successful. Two years later, the cartridge and AR’s that chamber it have yet to hit the market. At the 2010 Shot Show, Remington’s booth was still announcing the ‘introduction’ of the cartridge. Industry rumors are that the cartridge is having trouble living up to its advertised ballistics. Even still, rumors aside, if the cartridge/rifle combo ever comes to major release, it is just a medium game rifle in the first place, and secondly, has already been made obsolete.



Firing the 6.8 Remington.


Big Game
Here is where modern adaptation of the AR15 really takes shape. The AR has not been seriously looked at as a legitimate big game rifle. That is until now.

In 2004 Olympic Arms introduced a truly revolutionary design in the AR. Using the standard AR15 lower, Olympic now offers upper conversions in the Winchester Super Short Magnum calibers. In spite of other big-bore options available to outfit your AR15 lower, none offer true bolt-action magnum ballistics.

Using parts reengineered in-house, Olympic Arms modified barrel extension, bolt, bolt-carrier, and upper receiver allow for the use of all three chamberings of the WSSM series. The 223 WSSM has ballistics that equals the popular .22-250, and the 243 WSSM betters the 243 Winchester. When you get to Winchester’s largest caliber chambering of this cartridge, the 25 WSSM, you start getting into beefier numbers. The 25 WSSM in its short, fat little brass, exceeds what a .25-06 load will do in most cases.

But to get to real, honest to goodness big game ballistics you need to approach what the venerable .30-06 will do. That is precisely what you find in the Olympic Arms proprietary cartridge the 300 Olympic Super Short Magnum (300 OSSM). This cartridge will throw a 150 grain bullet Grand-Slam® bullet at 3,000+ feet per second out of a 24” barrel. With external ballistic n umbers matching or in some cases superior to the .30-06, there are few if any North American big game species that you could not hunt with your AR15.


Author's son Wyatt firing the 7.62x39 upper. Look closely and you can see the brass beginning to extract ever-so-cleanly from the Olympic Arms chamber.

Closing thoughts:
When considering a multi-purpose firearm, there is really no better choice than the AR15. From a pistol length system, to a long range rifle capable of surgical precision, to a legitimate big game rifle, this is it. If you are considering the purchase of your first AR15, check all the manufactures for the style and caliber you are looking for. Also keep in mind that the market value of new AR’s can fluctuate wildly due to sociopolitical current events, so shop in a timely manner to get the best deal.


About the Author:
Writing since high school, and a product of western PA farm country, Tom is a decorated Combat Infantry Veteran of Desert Storm, prolific hunter, published author, and has served in the firearms industry for the majority of the last 25 years. Tom is also the founder and President of www.oa2.org, a popular internet based AR15 related community. An itinerant evangelical pastor, Tom, his wife Sonja and their three children live in Bonney Lake, WA.

Write the author at rattler@oa2.org

[f8talh8red]

wow, that was an amazing article. i have had my ar since feb 09 and i learned some stuff from this that i did not know. i dont know if i could ask for a better explanation, from a first time buyers prespective or a repeat offenders(people with brd i mean).

great job tom, keep it up
josh

[Thom]

[Globemaster]

[melensdad]

Tom very nice article, well done for those who are new or unfamiliar with how flexible the AR15 platform really can be!

I think it would have been good if you could have included a simple mention of the 458 Socom and the 50 Beowulf when you mentioned the 450 Bushy. I'm not sure why you had to backhand slap the 6.5 Grendel. Still those comments aside, the article was excellent and well rounded.

I also think you did a nice job working in the 22lr conversion kits, given the space constraints of an article that had to cover so much ground, you managed to work that in with a reasonable explanation.

[f8talh8red]

this is somewhere in the piece.

As a survival too, it is simply unmatched.

i think it should be TOOL. or maybe tooth?

[shootermcmillan]

Good read Tom.

[TravisM.1]

Good write-up.

[Rattler]

[BlackRidge]

THAT was an awesome read! Great pics to compliment it

[Rattler]

The issue of Suvival Quarterly that featuires this article JUST hit the streets. check out www.survival.com for details and subscriptions.

Thanks for the kudos!

[Globemaster]

well ... I guess it’s time to head over to Barnes & Noble

[BlackRidge]

LAZY LINK to the subscriptions page

After looking through whats been covered in the past, I'm signing up for sure!!

[Globemaster]

B&N does not carry that magazine ...

[Eighty 0ne]

Great write up Tom! Very good read.

[BlackRidge]