SLR15 Rifles AR-15 / M-16 / M-4 ARMORING COURSE
When: April 1-2, 2014
Where: Parro's Gun Shop in Waterbury Vermont
We conducted a 2-day (16-hour) AR-15 / M-16 / M-4 Armorer Course at Parro's Gun Shop in Waterbury Vermont. This was our fourth time at this location, and we look forward to many more courses here. The onsite facilities offer a great training room with plenty of table space, decent lighting, and a wall that allowed us to project 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, many of them SWAT.
Rifles represented in this course were Bushmaster, Colt, Daniel Defense, Sig Sauer, BCM, and a couple of custom builds.
Day-1: On day 1 we 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.
Next we covered the proper way to field strip a rifle from the user level, and how not to cause damage or premature wear on the rifle. Once field stripped , proper maintenance was shown of where and what to clean, how to clean it, and why some areas need specific cleaning. During the maintenance with lots of myths dispelled (to include what firing pins designed for, and what they are not to be used for). Quite a few of the rifles present were fouled, which gave everyone the opportunity to see what fouling is, what it does, and how easy it is to remove using the proper method, and why it is our recommendation to remove it in certain areas before it breaks off in chunks or causes issues. Once user level maintenance was covered, we moved into armorer level for maintenance, inspections, and repairs.
Firing pins were inspected. We had all AR15 firing pins in students guns, so we showed the M16 firing pin, which allowed us to show and discuss both. We had no damaged firing pins in this class. We showed several damaged firing pins that someone had used a punch, this allowed us to discuss how this can lead to fail to fire or the catastrophic situation where the gun blows up. We also showed competition firing pins, and why we do not recommend that these be used in a battle weapon. We showed several examples of firing pin retaining pins, how they are made, and did inspections on them. We had a couple of firing pin retaining pins in this class that needed replaced due to wear and stress. We also showed several examples of firing pin retaining pins that were worn out or broken, to include aftermarket styles. Anyone who had a worn pin had theirs replaced.
We went through the complete bolt assembly. We covered proper disassembly, inspections, machining, metals and finishing, upgrades for reliability, stress on parts, life expectancy of parts, breakage, etc. No rifles in this class had metal injection molded extractor "MIM", of which we showed several hands on examples of these failing, but the ones in class were still functional. We removed the ejector assembly, and several of the rifles present had major fouling in this area, so we discussed why these should be maintained on a regular basis. It is my opinion that the ejector system should be lubricated with a good weapons lube like Slip2000 EWL that will keep it lubricated in all temps, to include sub zero and hot (yes it gets in Vermont), that will protect from rust, keeps moisture out, and breaks down carbon build up and keeps things lubricated where metal rubs metal. The ejector tracks were cleaned, and the ejector assembly was lubricated and reassembled, and inspected for proper function.
We went into carrier keys (gas keys), their machining and different types, along with the three most common screws. This class had only two bolt carrier keys that needed better staking. The MOACKS staking tools that we supply were put to good use, the MOACKS does a great job a staking (this is whey we supply these in our armorer kits). On day-2 several students brought personally owned bolt carriers that needed staking, and they were allowed to use the MOACKS tools. Everyone was introduced to the bolt gas rings, which we had two types present, we discussed the differences, and covered their proper installation order. Several students had worn gas rings that were out of spec, of which we supplied replacements.
The rest of the day was spent on understanding timing, and going through the entire lower receiver assembly, specialty tools and fixtures. This class was a mix of collapsible stocks and A1 Military stocks. Most the collapsible stocks didn't have their spanner & castle nuts staked (only hand tight). One castle nut had been locked down with a thread locker. Upon reassembly , the castle nuts and lock rings were staked into place. We showed everyone the proper way to remove the collapsible stock assemblies, especially when working with aftermarket slings mounts that may get in the way. We supplied several different fixtures and wrenches which made this task easier, and assisted everyone with stock removal. There was one rifle with Magpul sling mounts, we specifically covered the locking tab on this mount. For the Magpul sling mounts, we supply a special wrench that allows people to work around this mount as it is in the way when using most wrenches. Everyone removed their stock assemblies, inspected the threads, and cleaned up any thread issues present. We then moved into the rest of the lower receiver. We spent time on going through the cycles of fire, and the timing cycles of this weapons system, and what effects that timing cycle. Everyone disassembled their lower receivers, looked at sear engagements, springs, and how things worked. At the end of the day everyone reassembled their rifles and made sure everything was in working order.
Day-2: We started with a review of everything we covered in day-1, this included going back through explanations and demonstrations of timing, timing issues, dwell time, and how this pertains to how the weapons system runs smoothly, and when it isn't running then what it might be and how to fix it. There were no rifles present that had been set up for use with a suppressor. We discussed suppressors, covering the change in timing issues when using suppressors, along with maintenance and wear issues. Barrels represented were 16" & 20". We showed several different lengths of barrels and gas systems, and discussed how this relates to dwell time, and how this translates into a proper running rifle. We also supplied several variations of different gas systems on 16" barrels and shorter, which allowed us to go through the different personalities in how each of these systems run or don't run, and what the advantages or disadvantages are. Everyone was shown hands on explanations of how these effect timing/dwell-timing and diagnosis of issues.
A compete detail strip of lower receiver was gone through again, at which time we covered in great detail machining issues of what is good and what is not so good. We had three rifles in class that had the Rock River two stage triggers. We showed the Geisselle and other 2-stage triggers, which gives everyone a hands on look and feel of the differences of what they do and how they perform, everyone seems to favor the Geisselle for its quality as compared to the others. Lots of troubleshooting issues are covered during this section. Once done with machining, we go through all variations of full-auto and burst rifles. Everyone was allowed to go hands on with the full auto system, and we also covered conversions for agencies with DRMO weapons. There were no burst trigger groups in class, we went through the standard burst system in great detail as several of the people present had Military time hanging over them. The lower receivers were reassembled, lubricated and inspected for proper function & fit. The stock assemblies were properly indexed and collapsible stock spanner nuts and castle nuts were staked into place.
The afternoon of this day we go through the entire upper receiver assembly. There were no piston guns present, but we discussed and showed the difference in this concept of system, and covered that their personality traits, to include stress and troubleshooting. Everyone is allowed to rebarrel a rifle with they wish. When gauging, we found that most of the barrels in class were not mounted correctly, which results in premature wear and stress. Several of the rifles had worn out gas tube seals due to improper barrel mounting. Everyone was able to correct their barrel indexing. On all of the barrels pulled, none of them had been put together to the Milspec from the manufacturer. Every barrel that was pulled, was remounted to Milspec, torqued, and properly indexed. The end of the day is finished up with everyone inspecting and gauging things like headspace, firing pins, chambers, 4 gas seals, etc. Everyone's rifles gauged and inspected correctly.
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 Interchangability, 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
Greg Sullivan "Sully"