SLR15 TACTICAL LAW ENFORCEMENT SHOTGUN ARMORER COURSE
When: April 3-4, 2014
Where: Marion Massachusetts Police Dept
We conducted a 2-day (16-hour) Law Enforcement Shotgun Armorer Course at the Marion Police Dept. This was our second time at the Marion Police Dept for an armorer course, and we look forward to many more. The onsite facilities offer a classroom with plenty of table space, decent lighting, and a large screen that we were able 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. In this course we cover the Remington 870, Mossberg 500/590, and Benelli M1-90/M2. Shotguns represented were mostly Remington 870's, Mossberg 590's, and a couple of Benelli M1-90's.
The day started with an introduction of all present. 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 most of the general work on the shotguns, and we also supplied specialty tools for shell latches and restaking shell latches, etc. Everyone was supplied with Slip2000 "EWL" Extreme Weapons Lubricant and #725 Cleaner Degreaser, etc.
We started the day with an overview of all three weapons systems. A short session of nomenclature was covered, at which time covered every feature and exterior piece of the shotguns was covered, to include all the hidden design features that most people are not aware of. Everyone was taught the procedure series of checks that we recommend. Everyone was taught a hands on session of the eight basic functioning cycles of the shotguns. For this everyone was supplied with action proving dummy rounds, we prefer these over range dummy rounds, as the action proving dummy rounds offer the same feel and weight as live ammunition. From there we broke the same eight functioning cycles down further, it is amazing how much you can feel in the mechanical action of the locks, latches and levers, as you slowly cycle the action.
Everyone was shown the proper way to field strip each of the three shotgun systems. Once field stripped, we inspected the barrels, where many of the barrels present were fouled. The fouling inside the barrel is generally plastic from the shot wadding, mixed with powder and shot residue. Everyone was shown that they needed to clean the chamber and bore, as these are different diameters and require different brushes. We also showed all the other hidden areas of the barrel that need to be kept clean for proper functioning of the bolt assembly and barrel to receiver fit for lock up etc. Also shown were a multitude of tools, brushes, and jags for cleaning the barrel. Everyone with fouled barrels were allowed to clean them, as a hands on session of trying the different methods and tools shows what works better. Everyone was supplied with Slip2000 #725 Cleaner/Degreaser, and Carbon Killer/Cutter, which help to cut through the fouling rather quickly. Barrels were inspected for damage,stress, missing parts etc. Once overall maintenance, field stripping, nomenclature, and inspections was covered, it was time to get weapon system specific.
We started with the Remington 870. Once field stripped, we looked at the barrels inside and out, and how they are mounted and retained. We showed variations of 870 barrels with and without the magazine cap retaining detent style barrels are retained, versus the traditional style, and how these parts should not be intermixed. Everyone's barrels had the retaining detents. We showed how the detents work, how they are replaced, and staked into place. We showed how the non-detent style parts, bow these work, and why some of these cannot be intermixed.
The action bar assemblies (foreends) were removed and disassembled. The action bars were inspected. Everyone was shown what happens when you use the wrong method or tools, where these foreend assemblies get damaged. We had a student who brought a shotgun that his agency was having trouble with it cycling, he stated that his Officers are having to butt stroke the ground to get empty casings extracted from the chamber. Taking a look at this problem gone, it was discovered that he had bent action bars, along with a cracked polymer foreend. The action bars were bend from improper usage, these were replaced. The polymer foreend was cracked from Officers forcing the action bars rearward, this foreend was also replaced with the new action bars and everything work like new. Everyone was shown several different wrenches for working on the foreends, and we recommend that they have a wrench for this instead of the flat piece of metal that come from some aftermarket supplier. The Foreends were removed, and the action bar assembly was inspected. Magazine springs and followers were removed. Several people found major debris inside the magazine tube, and they were shown the need for a magazine tube brush. We showed several examples of magazine springs and followers, and why there is a need for the 870P spring or a heavier aftermarket version (I have a preference for heavy duty aftermarket springs from companies like Wolff). We also showed several examples of extended magazine tubes, and the feeding issue than can happen if they are not mounted properly, and discussed why the clamp is used.
We moved into the bolt assemblies, slides, action bar assemblies, and how they integrate together. Bolts were disassembled and reassembled, and inspections were done, showing where debris and corrosion is found. Most of the 870's present had rust and/or crud in the extractor channel, this is why we recommend that these be removed on a regular basis, cleaned and lubed. We demonstrated how to remove the firing pin and locking block assembly, at which time everyone was introduced to splined pins, and shown the proper way to remove and install them. Once everyone disassembled their bolt carrier assemblies, everything was cleaned and inspected. One student had a strange firing pin inside his bolt, of which after doing a little research, it was determined that it is a 1187 SuperMag firing pin, of which was measured and showed to be .006" longer than a stock 870 firing pin. I contacted a few people that I know at Remington, who stated that this was the first time they have heard of of this. The firing pin was replaced with a new one. On the final assembly of the bolt group, everything was properly lubricated, and inspected for function.
Stocks were disassembled and removed, inspected for stress, repair and modifications of them was also shown. Stock bolts, washers, stock bearing plate, and studs were inspected, and replacement of the stud was also shown. We showed the need for a stock bearing plate, and everyone that needed them had them. We showed several types of aftermarket stocks, slings and mounts, which we had several variations of Knox stocks present. There was a group consensus of liking of the shorter length of pull on the Hogue youth stock. Stock assemblies were remounted.
Trigger groups were removed, and cleaned. We showed how the clean the trigger group. We removed safety assemblies, inspected the triggers. Everyone removed the rear bushing, and how the rear pin is retained. We went through sear springs and showed 4 different types, everyone had the correct heavy Police springs. Carrier assemblies were also removed, cleaned, and inspected. Trigger groups were reassembled and gauged. We went through trouble diagnosing on the trigger group, and showed how mistakes can be made when cleaning which makes it so it doesn't function. We also showed the key out trigger groups and parts, and showed why it is our recommendation that these not be used on a combat shotgun for Law Enforcement purposes.
We went through shell latches and inspections of what is going on inside the receiver. We showed how to inspect, replace, and repair the shell latches. We provided several different tools for staking shell latches. We had one shotgun with a loose left shell latch, this was realigned and staked by the Officer. Ejectors were then inspected. We showed the process for tuning and replacement of ejectors and ejector assemblies. We had two shotguns present that had loose ejectors, of which the owners were able to tighten and tune them. Nobody had a broken or missing ejector system, but we brought an 870 with us that people were allowed to do replacements on.
Everyone was shown hands on examples in changes in parts, and the flex tab trio. We showed how the flex tab trio works, and why we recommend that it be in all Law Enforcement shotguns. The end of the day allowed everyone to reassemble their 870's. They were checked for proper function in all 8 cycles, checked with action proofing rounds, gauged for things like headspace, etc.
Day 2 started with a review of day-1, and a quick question and answer session, along with going back through the 870 to make sure everyone was comfortable. Next we went over the Benelli M1-90/M2 system. Field stripping was shown, and everyone was allowed to practice this, as this is a simple gun to field strip once you know how. There were several different two eras of Benelli's present, so it was easy for people to see the changes in evolution in simple things like field stripping. Once field stripped, we showed proper maintenance, where you find different places where fouling builds and can cause issues. Barrels were inspected, of which showed fouling, and discussed why we see more fouling inside a Benelli barrel when compared to others. There were two types of Benelli sight systems, present, of which we covered how both work, are adjusted, and replaced. The ejection system was shown, maintenance and inspections were demonstrated, and replacement was shown. Foreends were also inspected, and the different eras in washers and why these are to be used. We showed several examples of broken and stressed cams. Extractor replacement was shown, and we showed a broke extractor in our collection. We showed the difference between the 3" and 3.5" parts.
Stocks were removed, and repair and replacement issues were shown. Receivers were inspected. The recoil tube assembly was also covered, with an emphasis on proper maintenance. Trigger groups were covered, and upgrades and replacement issues were also covered. Everyone was shown the differences in eras of carriers and bolts, and how they integrate with each other. Carrier latch inspection and replacement was also shown. The use of aftermarket parts was also shown. An emphasis was made on how this inertia system works, how to make sure it reliably works, and how there is a lot of misinformation on troubleshooting on this system (to include using aftermarket accessories).
We moved into the Mossberg 500/590 type system, in this class we had all 590A1’s except for one model 500. The proper way to field strip these was shown. Everyone was practiced field stripping until they were comfortable. Next we covered the barrel assemblies. There were two different versions of the barrels in this class. Magazine tubes, springs and followers were inspected, and replaced if necessary. Magazine tube repair and replacement was also covered.
Foreends were disassembled, inspected, and reassembled. Timing cuts on the action bars were inspected, noting that these cuts were similar in concept to the 870's. We had one 590A1 with bent action bars, it looked like it has been loose for quite some time due to the wear that was present, it was replaced with a new one. Stocks were removed, and they all inspected just fine. We showed several examples of shoulder and pistol grip stocks, and how they integrate.
Bolts assemblies were next. We started with removal of the firing pin assemblies, of which we had 5 guns present from 3 different agencies that were taken out of service for failing to fire, stating that they had been getting light primer hits. In each case that guns had been sent back to Mossberg, which returned them stating that they couldn’t find anything wrong. This is where I like a good challenge, so I gave the guns a very good look over. What I found in each of these is that the firing pins were shorter than normal, the average of these were .0046” too short, with .0069”. These firing pins were replaced. All of these guns were checked for proper lock up, hook space, headspace, and nothing else was found to be out of the ordinary. We went through the extractor assemblies (one student got ahead, and put them back in wrong, causing a non functioning weapon), everyone got them reassembled in correct order. People were shown the changes in era of the bolt assembly parts. Everyone was shown the difference in the extractor assemblies between the right and left sides, how they function, and why they cannot be mixed between sides. The ejection system was shown, and we showed everyone how to do replacements, along with showing whey to be careful with aftermarket accessories. Everyone was shown how the carrier integrates with other parts during the feeding cycle.
Trigger groups were removed. We walked people through disaassembly and reassembly of the trigger groups, which gave a great hands on opportunity to see how they work. We showed their proper cleaning and possible maintenance issues. There was one 590A1 trigger group that had a broken hammer. Upon further inspection, it appeared that he action lock trigger disconnector spring hand somehow slipped out from the disconnector, which possible kept the hammer from being recocked, and when the user forced the action back caused that action to slam into the hammer and break it. The broken hammer, disconnector and action lock trigger disconnector spring were replaced, and the trigger group was back in working order. Safety assemblies were shown, along with upgrades and aftermarket styles. One student had a borken safety on a model 500, which the safety was plastic (we see these plastic ones broken on occasion, and it is our recommendation that metal ones be used on combative and tactical type shotguns), this broken safety was replaced and it was back in working order. All guns were then reassembled, everyone checked for proper function, and gauged everything. The last part of the day was spent on going through all the shotguns and going inspections, these include headspace, trigger press, etc.
CY6
Greg Sullivan "Sully"
SLR15 Rifles
TheDefensiveEdge.com
(763) 712-0123