SLR15 AR15 / M16 / M4 / AR308 Armorer Course
When: March 30-31, 2026
Where: Lafayette, LA
We conducted a 2-day (16-hour) AR15 / M16 / M4 / AR308 Armorer course that was hosted by the Lafayette Police Dept. We have taught an Armorers week of courses here for over 2 decades, and we look forward to more in the future. The training room was set up to allow plenty of table space. There was a large projection HDTV system that allowed us to project animations and power point onto.
The student base was all Law Enforcement from Louisiana and Mississippi. Rifles represented in this course were SLR15, Colt, Watchtower, Daniel Defense, Aero Precision, Core 15, SOLGW, BCM, DPMS, Bushmaster, Larue, and a few custom builds.
Day-1 started the day by 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 why 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. We also showed how to clean suppressors and why. Several people took advantage of our suppressor cleaning equipment, and cleaned them during class.
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. Bolts were fully gone through, which included extractors, extractor springs/inserts/O-rings. The ejectors were removed, cleaned, and inspected.
Note: There were a few gas keys that needed better staking. We provided staking tools, and those that needed to fix them first checked for proper torque, then fixed the staking.
Note: One agency went to fix the staking on their Watchtower guns, which we have them check for proper torque first, and they found that the front gas key screws would just spin. When we see gas key screws that just spin, it is usually caused by broken screws. When the removed the gas keys, both of these 2 carriers had broken front screws, which is why they would just spin freely. There wasn’t enough of the screw left sticking up to get a good hold on it, and what little of the screw that you could try and move the screws was tried, but the broken screws wouldn’t move, which is usually an indicator of a thread locker. I suggested that they contact Watchtower, and see if their customer service would either repair or replace the bolt carriers.
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.
Note: One Officer had a bent hammer spring on his single stage semi-auto Core 15 rifle. The left leg was bent 45 degrees to the rear, and the right leg was straight. This is something we have seen before, and the usual cause was as suspected. The hammer had an oversized diameter on the left pin strut, as compared to the right which was smaller in diameter. This hammer also had a wider disconnector shelf, which is generally on a burst hammer. A simple replacement hammer spring is not going to be the repair, instead the hammer and trigger group needs to be replaced as a group. I suggested they contact Core 15 and see if they will warranty the issue.
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 had collapsible stocks. We covered the proper mounting & gauging, and proper castle nut staking on the collapsible stocks. Several people found unstaked castle nuts, so this allowed everyone to take advantage of our tools and get things done correctly.
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, they 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. This also led us into piston systems. We covered how the piston system works, break down and maintenance of the system (Yes piston systems do get dirty and have to be cleaned and maintained), how to properly adjust for timing changed, and trouble shooting. We also covered dwell time, and how it pertains to cycling issues, and hopefully got the point across of why we do not recommend barrel lengths shorter that 11.5" on unsuppressed rifles.
Note: During the timing session, we showed examples of adjustable gas blocks, and we also showed the gas control system from https://www.riflespeed.com/, which we like as it is adjustable with a quick turn by hand to one of the 12 different settings, and is well built for durability.
We showed how suppressors are properly mounted and gauged. Several people took advantage of the bore gauges that we make, and checked their alignment on their rifles that had suppressors.
The last half of day-2 was spent on the upper receiver assembly. We covered barrel removal, mounting, fixturing, gauging & inspections. We show numerous ways to fixture a barrel into a vise, and our preference as to which fixtures/methods to use when and how. We showed how to mount, then properly torque and gauge the barrel system, which ensures it is in proper working order.
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
Nomenclature
Identification of Group Components
Semi, Burst, and Full Auto Parts and Conversions
Complete Armoring Disassembly / Assembly
Barrel Replacement
Cleaning and Maintenance
Sight and Distance Considerations
Ballistic Issues
Barrel: Twist, Length, and Profiles
Gas Systems & Piston Systems
Parts Interchangeability, including Brands
Headspace
Firing Pin Protrusion
Trigger Systems
Chamber Inspection and Issues
Troubleshooting, diagnosis & repair
Gauging, Inspections, Stress & Interval Issues
Accessories and Customizing
Tool Options and Selection
SOP/MOD Accessories and Additions
CY6
Greg Sullivan “Sully”
WeaponsArmorer
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123