Considerations before you throw the switch on that Frankenstein AR

If you have not been keeping up with the different gun magazines over the last 5 years (or you’re just really and truly unobservant), you may have missed the explosion that has happened; AR-15’s.  Everywhere you turn there are articles, books, videos, blogs and catalogs that are dedicated to the AR-15 platform.  Immediately after the Obama Administration took office AR sales skyrocketed as people prepared for a reinstatement of a Clinton-era style Assault Weapons ban.  For a while parts were scare, and lower receiver prices were going up like gas prices.

Thankfully no such ban went into effect, the market has stabilized and you can now find OEM parts and after market parts again.  This has all led to more ARs being produced than ever before.  Americans are simply fascinated with all things military.  We love the fact that we can own a similar version.  Perhaps it makes us feel empowered, or maybe it makes us have a greater sense of our own history.

As the AR market broadens, there are many people who are interested in assembling their own rifle.  Most people are drawn to the fact that they can actually save a little money by putting in the labor themselves.  Some people have been tearing their matchbox cars apart since preschool and they simply have a desire to better understand the workings of the AR.  Whatever your reason, quality of parts should be your main concern.

As a manufacturer of AR’s at Mossy Creek Arms, I know the difference between quality parts and sub par performers—because I see them everyday.  To the newly indoctrinated however there may be a fair amount of confusion so here are the basic points to consider before jumping out into the market:

Cost of Assembly Tools

There are several tools that you will need to put that AR together, some of which are basic like a hammer, screwdriver, a vise, two blocks of wood to hold the flattop upper while others are more specialized like wrenches for the flash hider, a barrel nut wrenches and torque wrenches.  The list could very well go on and depends on the type of AR-15 you’re making and the directions you’re following.  Make sure you budget for this when considering your build because what began as an exercise in frugality can turn into a money pit quickly if you don’t have access to these.

Quality of Parts

The most important place to look is the barrel. In terms of accuracy (and what else really is there?) this is the centerpiece of the gun.  What type of guarantee are you getting? Our shop demands 1 MOA from our non-chromed barrels.  Many others are content for pie plate accuracy.  What are you willing to accept?  This is more than an obvious question because price mounts neck and neck with quality and modifications can be tricky at home.  All told, this is not a component I recommend skimping on.

Part Compatibility

I recently looked at a batch of parts that were non-compatible.  We were looking for some lower kits that were listed as OEM, but the disconnecters were out of spec and the plunger for the bolt catch would not fit in our lowers.  These are not parts that you want to modify.  As you consider your build I would highly recommend getting all the parts you can from the least number of “sources” to ensure functionality between parts.  Frankenstein guns made from thirty different vendors are prone to malfunctions.


If you bring the monster to life, understand, you mad scientist, that you are the warranty.  Companies, like DPMS, will not stand behind your build.  In fact, DPMS marks all lowers not assembled at their factory with a “K” at the end of the serial number identify it as a separate entity.  If you’re prepared to incur this risk, more power to you.

(Photos courtesy of the SFGL)

Read More On:

Latest Reviews