SLR15 Rifles AR-15 / M-16 / M-4 ARMORER COURSE
When: April 30 - May 1, 2014
Where: Anoka Police Dept, Anoka MN
We conducted a 2-day (16-hour) AR-15 / M-16 / M-4 Armorer Course at the Anoka Police Dept in Anoka MN. This was our 5th course 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, a large screen 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. Rifles represented in this course were a mix of Colt, SLR15, BCM, Bushmaster, Smith & Wesson, DPMS, Daniel Defense, Rock River, 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 that firing pins are not designed for using as a punch or scraper). Most of the rifles in this class had fouling build up, this fouling allows us to have students clean the fouling, show where it needs to be cleaned and removed, and how easy it is to remove and why. It is our recommendation to remove heavy fouling build up in specific areas, as fail to do so will cause premature wear and erosion (especially when it comes off in chunks). Once user level maintenance was covered, we moved into armorer level for maintenance, inspections, and repairs for the rest of the course.
Bolt carrier assemblies were disassembled. The firing pins were inspected for type, we had 3 types in this class. We showed a couple of examples of damaged firing pins, where they had been used as a tool to scrape or punch something out, this drove the point home that firing pins are not to be used as tools. We had one rifle with a competition firing pin, and we showed why we do not recommend using these in duty type weapons. We covered the firing pin retaining pins, showing several different types, materials used, inspected them, and showed why these need to be replaced when erosion or damage is present. A couple of students had eroded retaining pins, one had a broken/missing leg, and another had been beat on to the point it was bent out of its normal shaped, all of these were replaced.
We removed the extractor assemblies, which people found a lot of debris, and we showed why this debris need removed. With the extractors out, we went through the different ways that these are made, inspecting them for stress. Extractor spring assemblies were removed and inspected. We showed the numerous types of extractor spring inserts that have been use and why, anyone without an insert was provided a new one. We looked closely at the extractor springs, showing the evolution of this and the differences in all the springs that are available. We had a couple of MIM type extractors in rifles, and we showed where we have seen some of these fail and why. The ejector systems were removed, and people got to see why these should be removed and cleaned out on a regular basis, as we found rust & corrosion, along with one broken spring (which was replaced). We had everyone remove their gas rings, which we had 3 types in rifles in this class. We showed what the rings do, and when & why these should be replaced. We inspected the bolt carriers for machining and finishing, this helps give everyone a full understanding as how things integrate. Carrier keys (gas keys) were inspected, looking at the machining, and we showed the three most common screws used. We had a couple of gas keys that needed better staking, and the MOACKS tools that we provided were put to good use. Several people brought more carriers the second day of the class and used the MOACKS to correct their factory staking (or lack there of).
The afternoon of day-1 was spent on going through the lower receiver assembly, understanding timing, suppressors, working with specialty tools and fixtures, etc. About 2/3rds of the rifles in this class had some type of collapsible stock on them, mostly M4 types and a couple of Magpul MOE & CTR versions. Looking at the spanner nuts & castle nuts, it was found that the majority were not staked, and a few had a thread locker. Several students stated that their spanner nuts had come loose in the field and they didn’t know why. Note: When we finished with the lower receiver assemblies that last time on day-2, all students locked the spanner nuts into place by staking them after proper gauging and indexing. We demonstrated the field repair method and shop methods when working on collapsible stocks for removal, installation, and making proper adjustments. We supplied several different fixtures and wrenches which made stock work safer and easier. We had several rifles with single point sling mounts, a mix of Magpul, GRSC, Troy, Daniel Defense, Crosstac & Blackhawk, among a few others, where sometimes traditional stock wrenches don’t work well, so we provided several wrenches that work around these sling mounts. All stocks were removed, inspected, and if there were damaged threads we allowed everyone to clean these up with the proper tooling. After stock assemblies were removed, we then moved through disassembly of the rest of the lower receiver, looking closer at what sear engagements are, how the springs and pins integrate, etc. Time was spent going through the eight cycles of fire, proper timing and pressures, buffers and action springs, and gas impingement vs piston systems. At the end of the day, everyone reassembled their lowers, put the rifles back together, and made sure everything was in working order before they left.
Day-2 started with a going back and reviewing what was covered on day-1. We reviewed maintenance, the bolt carrier assembly, extractor & ejector systems and upgrades, bolt rings (gas rings), carrier keys & staking, and timing. When it came to timing, we built onto what had already been covered , and added on with troubleshooting when it comes to timing, dwell timing, suppressors, and more. We had two rifles in this class that had suppressors, one was a direct thread mount, the other used an adapter. We spent time going through what suppressors do, how to tune the rifle for best suppression, mounts, maintenance, stress, etc. We covered the traditional rifle and carbine length gas systems, and showed several different mid-length systems, and we dispelled a lot of the myths on gas systems concepts.
Everyone went through a complete disassembly of the lower receiver once again. Once totally stripped, we inspected them for machining, erosion, and stress. We went into great hands on session of inspecting the trigger groups, looking at good & bad for machining, materials used, and finishing. We defined with a hands on session the personalities of different trigger systems like the single stage and 2-stage variants that are used by different manufacturers. We had a couple of different 2-stage triggers in class from Rock River, LMT, CMMG, and Geisselle. Once everyone went hands with the different 2-stage triggers, most stated that if they were going to use a 2-stage trigger it would be a Geisselle. When we go through the lower receivers, especially in great detail of the machining and timing, we cover a lot of troubleshooting diagnosis of issues and how to deal with it. Next we move into trigger jobs, how they are done correctly and incorrectly, and how to find if someone has done something that they shouldn’t have on a rifle, and why we recommend that trigger jobs not be done on duty rifles. From there we covered full-auto and burst system s, where everyone gets to go hands on with different variations of these. We covered conversions for agencies with DRMO weapons. There were no burst trigger groups in class, but we made sure everyone got to go hands on with these, especially with anyone that had Military commitments that may come across one. The lower receivers were reassembled, properly lubricated, and inspected. for proper function.
The rest of day-2 was spent on the upper receiver assembly. We went through the machining on the upper receiver and parts, and how they integrate together. We showed several examples of badly machined uppers and parts, where things broke (like charging handle and latches) and why. We inspected barrel mounting, and found quite a few factory built rifles were barreled incorrectly that was causing stress and premature wear. Everyone is allowed to rebarrel and many took advantage of being able to do this in class. All of the barrels that had been mounted incorrectly, were remounted and gauged correctly. A couple of rifles had worn out gas tube seals due to improper barrel mounting, these were repaired and replaced to get them back in proper working order. On all of the barrels pulled, none had been mounted to the Milspec (except for the SLR15 ones). Everyone who pulled a barrel did put them back together to the proper Milspec, they were torque to spec, gauged and properly indexed. The last part of the day was spent with a review, then going through inspecting and gauging the rifle for proper headspace, firing pin protrusion, checking all 4 gas seals, chamber inspections, 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
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 System
Parts Interchangability, including Brands
Headspace
Firing Pin Protrusion
Trigger Jobs
Chamber Inspection and Issues
Troubleshooting, diagnosis & repair
Gauging, Inspections, Stress & Interval Issues
Accessories and Customizing
Tool Options and Selection
Iron Sights
Optics
SOP/MOD Accessories and Additions
CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123