SLR15 Rifles AR-15 / M-16 / M-4 Armorer Course

When:  October 8-9, 2018

Where:  College Park, Maryland

We conducted a 2-day (16-hour) AR-15 / M-16 / M-4 Armorer Course that was hosted by the College Park Police Dept.  This was our 2nd time teaching courses at this location, and we look forward to future ones.  The training room offered plenty of table space, decent lighting so people could see small parts, and a large screen and projection system that allowed us to show animated graphics of the weapons system, powerpoint 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 agencies from around Maryland, Virginia, Delaware, Rhode Island, and North Carolina.  

Rifles represented in this course were Colt, Sig Saure, DPMS, DRMO M16A1's and M16A2's, Daniel Defense, Smith and Wesson, Rockriver, Bravo Company, Palmetto State Armory, APF Armory, Ruger, LWRC, LMT, Anderson, 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:  When everyone checked their bolt carrier keys (gas keys) for proper staking, they found a Bushmaster, Ruger, Rockriver, DPMS, and Palmetto State Armory carriers that have very light gas key staking where the staking wasn't touching the screws.  These Officers used the MOACKS and Sully Gas Key Stakers that we had with us, and made the corrections.  

Note:  One Officers Colt rifles had a broken ejector spring.  It was replaced with a new one.  Broken ejector springs is something we see occasionally, especially with rifles with high round counts.  It is our recommendation that the ejection system be pulled on a regular basis, cleaned and inspected, and if a damaged or broken spring is found then to replace it.      

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. 

The last part of the day we spent on an introduction to timing, which we like to do so that it grows in peoples brains over night, in preparation of getting into great details of timing for day-2.  Everyone put their rifles back together, making sure that everything worked properly before we ended the day.    

Day-2 started with a review of everything that was covered on day-1, with some greater details and myths covered.  We then got into a session on the timing as it pertains to proper cycling, and showed what effects timing, and how & what happens when it is out or proper time, dwell time, suppressor issues, etc.

Note:  Several agencies in the class had added suppressors to their rifles.  None of them were aware that adding a suppressor can change the timing of the rifle, and they had experienced fail to extract issues.  Everyone now knows that they may need to slow the timing cycle when using a suppressor. 

There was one Sig Sauer piston rifle in class.  This gave us the opportunity to cover the piston systems, and their personality traits.  We showed how these work, adjustments of when/when not to adjust, and covered what the pros/cons are. 

Everyone in this class had collapsible stocks, and we showed the proper mounting & gauging, and made sure everything was properly staked.  Everyone stripped their lower receivers, which allowed a chance for further inspections, and we went through a session on troubleshooting.  We showed examples of good & bad machining on parts, and how this effects the entire rifle.  Lastly we went through full-auto and burst systems, showing how these work, and trouble shooting related to such.  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. 

The last half of day-2 was spent on the upper receiver assembly.  We covered barrel removal, mounting, gauging  & inspections.  Everyone was allowed to rebarrel their rifles or make adjustments.  We showed why people should be picky on how barrel nuts are indexed, and why there is a torque spec.    If barrel nuts are not indexed properly, it could cause 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.

Several Officers took advantage of the time & tools, removing their barrels.  Upon inspection of the barrels that were removed, none had moly paste, and several of the barrel nuts were not properly aligned, and one was loose as if it was never torqued to proper spec.  All barrels that were pulled,  were remounted, torqued and properly indexed.     

Once all the rifles were put 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
Barrel Replacement
Cleaning and Maintenance
Sight and Distance Considerations
Ballistic Issues
Barrel: Twist, Length, and Profiles
Gas System
Parts Interchangeability, including Brands
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

Greg Sullivan "Sully"
SLR15 Rifles
(763) 712-0123

Original Post

That was a great class. Definitely the most interesting, informative, and entertaining armorer class I've ever taken. Anyone working with AR-15s, whether for work or hobby, will get a great deal of useful knowledge out of this course. 

You can also add an Armalite to the list of inadequately staked carrier keys as well.


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