SLR15 AR-15 / M-16 / M-4 / AR308 Armorer Course
When: January 22-23, 2019
Where: Lake Zurich, Illinois
We conducted a 2-day (16-hour) AR-15 / M-16 / M-4 / AR308 Armorer Course that was hosted by the Lake Zurich Police Dept. This was our second course at this agency, and we look forward to more in the future. The training room offers great lighting, plenty of table space for people to spread out, and a large screen and HDTV's which allows us to project some powerpoint and animations onto, showing close up detailed pics of gun parts, and especially when looking at finer detail things like machining, stress cracks & wear.
This class was a mix of Law Enforcement Officers from different areas of Illinois.
Rifles represented in this course were Colt, Smith & Wesson, Sig Sauer, DPMS, Bushmaster, Armalite, DRMO Colt M16A1's, Rockriver, Aero Precision, Anderson, Aero Precision, Bat Arms, LMT, and a few home built guns.
Day-1 started with going through the course manual that all students are given. Students were supplied with their own set of basic tools that are necessary to do 95% of the work on their rifles (short of restocking and rebarreling, of which wrenches and sometimes fixtures are necessary), Slip2000 "EWL" Extreme Weapons Lubricant and #725 Cleaner Degreaser, etc. A short session of nomenclature was covered, at which time covered every feature and exterior piece of the rifle to include all the hidden design features that most people are not aware of, and everyone prepped the rifles for disassembly work. Everyone was taught the procedure series of checks that we recommend.
Everyone was taught our recommended way to field strip a rifle, and whey we do it this way so as not to cause damage, premature wear or stress on anything. We covered maintenance of where and what to clean, and what needs lubrication to keep it running. We showed why not to use the firing pins as tools. We showed everyone our recommendation of how to remove fouling and why, and everyone got to use our methods.
The entire bolt carrier assembly was covered, to include inspections, maintenance, upgrades, 3 types of gas rings, and differences in finishing and machining. carrier key (gas key) installation and staking, ejector systems, etc. Everyone was introduced to the different types of gas rings. We went through what each types does, and their proper installation order.
Note: Two Officers had early Colt M16A1's that had no extractor spring insert. One Officers had an Aero Precision rifle that had no extractor spring insert as well. We remedied that.
Note: This was the class of badly staked or not staked bolt carrier keys (gas keys). When checking bolt carrier keys, people found that there were lots that light staking where the staking wasn't touching the screws on several Bushmasters, several Rock Rivers, DPMS in AR15 & LR308. There were no staking marks found on a Smith & Wesson and 2 Aero Precisions.
Note: One Officers Colt M4 had a loose gas key that could be rattled by hand. Upon close inspection, you could see that there was plenty of bolt carrier key material that was staked into the screws so it was touching the screws, but the carrier key was loose enough that you could shake it by hand. When I tried to tighten the screws, they were able to be tightened a full 1/4 turn tighter, I have personally seen this before where the carrier key had plenty of staking material that was pushed into the screws, but the screws had come loose. I am a big believer in counter-staking the screws into the carrier key stakes, as a stake and counter-stake won't come loose unless you file things off.
We got into the lower receiver assemblies, starting with the fire control group (trigger group). We teach this in a building block format, starting with baby steps of getting things out and in, then build into how things work. Everyone learned how to install and remove things so you don't cause damage. We went through detailed inspections of all the sear engagement surfaces, spring types, single stage, and two stage trigger systems. At the end of the day everyone put their rifles back together, making sure that everything was in proper working order.
Day-2 started with a review of everything that was covered on day-1, with some greater details and myths covered. We then went back into trigger groups in great details, covering single stage, 2-stage, good and bad triggers, differences and options in spring systems, diagnosing problems when semi-auto turns into burst, and showing the differences in quality of triggers that are on the market. Once done with semi-auto trigger systems, we went into select fire trigger groups covering full-auto and burst trigger groups, to include replacement and diagnosing and repairs when experiencing malfunctions.
After trigger systems, we went through the rest of the lower receivers. Everyone in this class had collapsible stocks. We covered the proper mounting & gauging, and proper castle nut staking. Everyone stripped their lower receivers, which allowed a chance for further inspections, and we went through a session on troubleshooting. Once everyone was comfortable with the entire lower receiver assembly, the were put back together, inspected, and made sure everything is in proper working order.
We then got into a session on the timing. This is where we cover proper cycling, covering what effects timing, and how & what happens when it is out or proper time, dwell time, suppressor issues, etc, and how to get things into proper timing.
The last half of day-2 was spent on the upper receiver assembly. We covered barrel removal, mounting, fixturing, gauging & inspections. We show numerous was to fixture a barrel into a vise, and our preference as to which fixtures/methods to use when and how. For demonstration purposes, we fully disassembled a barrel and front sight base. Several Officers commented that the methods we show in how to disassemble and reassemble barrels and front sight bases was much easier that they had tried on their own. We showed why people may need to rebarrel, stress and premature wear during cycling and excessive wear on the gas or piston system. If barrel nuts are not torqued to their minimum recommended specs, things can come loose, and if it's loosed you can lose accuracy, being loose can also be a safety issue.
Note: We covered how to mount a gas block, and how to use our gas block alignment fixtures to get the gas block in perfect index with the barrels gas port. Our gas block alignment fixture can also be used as a barrel dimpling fixture, where being able to countersink the gas block screws into the barrel so it doesn't slip out of alignment is a good thing. Dimpling barrels and countersinking gas block screws is the minimal thing that should be done, it is my personal preference to drill and pin gas blocks to the barrel, which is something we teach in our advanced armorer courses.
At the end of the day everyone put their rifles back together, everything was inspected and gauged to make sure it was in proper working order. Everyone did chamber inspections, checked & gauged the four gas seals, firing pin protrusion, trigger press, and headspace.
Here is a brief overview of a few things that were covered:
History of the Weapon
Cycles of Function
General Disassembly & Assembly
Identification of Common Problems and Parts
Identification of Group Components
Semi, Burst, and Full Auto Parts and Conversions
Complete Armoring Disassembly / Assembly
Cleaning and Maintenance
Sight and Distance Considerations
Barrel: Twist, Length, and Profiles
Gas Systems & Piston Systems
Parts Interchangeability, including Brands
Firing Pin Protrusion
Chamber Inspection and Issues
Troubleshooting, diagnosis & repair
Gauging, Inspections, Stress & Interval Issues
Accessories and Customizing
Tool Options and Selection
SOP/MOD Accessories and Additions