SLR15 Rifles AR-15 / M-16 / M-4 Armorer Course
When: August 8-9, 2018
Where: Sunapee, New Hampshire
We conducted a 2-day (16-hour) AR-15 / M-16 / M-4 Armorer Course that was hosted by the Sunapee Police Dept. This was our first time doing a course at this location, and we look forward to possible future courses. The training room offered plenty of table space, decent lighting so people could see small parts, and was equipped with a HDTV 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.
The student base was all Law Enforcement Officers from different agencies from New Hampshire.
Rifles represented in this course were Colt, Ruger, Stag, Sig Sauer, Bushmaster, LWRC, Smith and Wesson, and a few custom builds. This class was about half piston and half gas impingement 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. There was also a discussion on other lubricants and where problems can happen if they freeze or get gummy.
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: Of the rifles present, there was a Ruger bolt carrier key screws that weren't staked, and there were also bolt carriers from Bushmaster that had light staking where the staking was only touching the screws lightly on one side. These Officers used the MOACKS and Sully Gas Key Stakers that we had with us, and made the corrections.
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: A couple of agencies have added suppressors to their rifles. All of these were baffle type suppressors. This let us to the discussion of how to properly mount suppressors, to include direct thread vs mounts (My preference is a mount). We also showed how suppressing a rifle will change the timing, and how to properly set up a rifle for maximum performance suppressed.
There were were several piston guns in this class from Sig Sauer, Ruger, and Bushmaster. This allowed everyone to see hands on examples of the differences in 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, and covered detailed maintenance of why/where/when.
Note: Two of the piston rifles present were from Sig Sauer. One Officer had been taking his piston system out and cleaning on a regular basis. The other Officer hadn't removed his piston system in about 3000rds, and when he tried to remove it, he found that it was stuck. It took some manual working it back & forth, along with some of the magic armorers juice (Kroil), and he finally was able to remove the piston assembly from its block. Once removed you could see a very large amount carbon build up that was causing things to be bound up. The Officer was able to be the carbon build up removed, and things were reassembled with ease. This allowed everyone to come to the conclusion that you do have to maintain piston systems, as they do get fouled and dirty.
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
Cleaning and Maintenance
Sight and Distance Considerations
Barrel: Twist, Length, and Profiles
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