A few updates here. I have changed the name of the gun from the DMTR to the Practical Marksmanship Rifle (PMR), because it has grown past being a dedicated training receiver and become my favorite rifle configuration to shoot.
I took the rifle as originally described through an Appleseed shoot back in august (AAR is here), and it performed beautifully. The more I shot this gun, the more I wanted to make it into a great all-round performer of every marksmanship task I could assign it. I took to calling the gun “The Musket,” and I guess these upgrades will become “The Musket Mk 2,” or perhaps just the “Mk 2.”
As many have said, this is more-or-less a variation n the M16A5 theme. So that seemed like a good place to start with upgrades. Since I am not a cloner, I didn’t feel the need to stick to any traditional vestiges of military usage (like the M5 RAS) that would normally wind up on an M16. I’ll go into detail about each of the upgrades, and why I changed them.
BLUF parts list (new parts in red)
Upper
BCM 20" government rifle with pinned FSP and A2 birdcage flash hider
Daniel Defense Omega 12
BCM Auto BCG
Rainier Arms Raptor charging handle
Trijicon TR24G in ADM Scout
Magpul Enhanced XTM Panels and Handstop Kit
Gear Sector Gen 3 QD Sling Mount
Lower
Spikes Tactical lower
G&R LPK
VLTOR A5 buffer kit
VLTOR EMod stock
BCM Gunfighter mod 1 pistol grip
BAD ASS-ST safety selector (Crank/Stubby)
Geissele SSA-E trigger
Noveske QD end plate
Sling
Short Action Precision Positional Sling
Weight: 9.2 lbs
Why I Did This: Daniel Defense Omega 12
There are a lot of great rails on the market today. If I was going to go for a pure “M16A4” look, then I should have used the KAC M5 RAS. However, that rail is not free floating, which was the whole point for me to install the rail in the first place given the amount of sling pressure I use. I always found the MOE handguards to be extremely comfortable, and was reluctant to take them off. So, priority number one was to free float the barrel.
Centurion Arms makes a fantastic drop-in rail, the C4, and it was my top preference for this project. However, I wanted to retain the ability to remove the rail and reinstall the plastic MOE handguad if I wanted to. I may not always want to keep the big aluminum rail in place, which means I didn’t want to cut off the delta ring assembly or front handguard cap. I also don’t have the tools to remove and reinstall the barrel (nor have I ever had training to do so). That left me with choosing rails that could install on top of the existing hardware.
Of the vanishingly few options that met my desires, the DD Omega was chosen. It installed easily, and feels extremely solid. My concerns about this configuration adding too much weight were alleviated when I found out that the Omega 12 weighs only a tenth of an ounce more than the C4 rail I had originally wanted to use.
However, I was met with another problem.
The shape of the rail feels a bit like an I-beam. I have also never appreciated the “cheese grater” feel of gripping a bare quad rail. This is part of the reason that I went to a slick sided modular style rail with my other projects. After a fair bit of dry fire, I decided that I needed to do something about the feel, hence the XTM panels. Those have been covered in great detail in many other places, so I don’t think anything needs to get said about them. They do their job, and they do it well. I find them very comfortable and solid on the rail. I now find the rifle to be quite comfortable to carry and hold In awkward positions. You will notice that I didn’t have the panels go all the way to the ends on the sides, as that leaves me room to install a flashlight mount at a later date at the front.
Another bonus to the Omega rail is the addition of QD mounts on the side rails close to the receiver. By attaching at these points, I have found that I can wrap the sling around my back and use it in a more “tactical” manner. This reduces the benefits of a loop sling around my arm, but does still over tension to stabilize the rifle in a pinch. As this rifle is not intended to be used this way on a regular basis, I don’t think this will be a regularly occurring sling configuration, but its nice to nice that there is an option.
Why I did It: Gear Sector QD Mount and Magpul XTM Handstop
The hand stop kit is more of an experiment than anything. I have gotten used to the slick bottomed feel of the MOE handguard and came to enjoy the simplicity of it. But I found a drawback of the previous configuration. When the sling was attached at the FSB sling swivel, I had to place my hand way out on the end of the handguard in order to get it properly wedged up against the swivel. For most positions, this wasn’t an issue. But sometimes, pushing my hand out that far straightened my arm and reduced how much elevation I could adjust with my elbow.
Once the rail was installed, I wondered how things would be affected if I moved the sling mount a couple inches towards the receiver rather than leaving it all the way at the end. I immediately found that this fixed my previous issue. It also gave me enough rail space in front to attach my Atlas bipod (if I so chose). I went with Gear Sector because I really like their low profile and sleek design aesthetic. I use one of their first generation flashlight mounts for my Elzetta on another AR. The difference between the first gen and third gen is that the first gen requires me to slide the mount from the end of the rail into the desired position. The third gen has a different recoil lug design that lets me drop it into any spot I need and tighten it at that point with no need to slide it around.
[CENTER]With Bipod
Without Bipod
[/CENTER]
I then installed the hand stop kit behind the sling mount. Though practice, I find that the front “nub” provides me an even better and more stable “lock up” in various shooting positions. Now, instead of wedging my hand between the rail and the sling swivel (which could sometimes result in a bad “pinch”), my hand wedges up against the front stop. As a bonus, when I take a more “tactical” stance, I can wrap my index finger around the front stop to offer a little bit more control.
The Normal Shooting Position
The ‘Slung Up’ Hand Position
A Bit More ‘Tactical’ Position
As far as the rear stop, I’m still on the fence. I don’t find that it offers anything to me as far as traditional shooting positions go. But it does help for the more “tactical” shooting stance. If anything, I find it works well for off hand when I place my support hand behind it (close to the receiver) and use it in a similar way as the front stop. I’m sure a lot of people who are into faster and more dynamic shooting find it useful. More time and practice will tell if the rear stop stays. When shooting in traditional positions, the rear stop can dig into my palm a bit. It hasn’t gotten uncomfortable, yet, but I’d rather not have it doing so. I already moved it back a bit by installing the “half panel” behind the front stop instead of in front of it as the directions dictate.
Hand Behind Rear Stop for Extra Elevation Leverage
Rear Stop Digging Into Palm in Normal Position
Why I Did It: Trijicon TR24G
The TR24 has been homeless for a while. I purchased it years ago for my vision of a general-purpose recce rifle. It served well in that role, but was replaced by a Vortex Viper PST 2.5-10x32. I didn’t want to get rid of it, because I’ve always liked the idea of having a suite of optics for various roles that can be interchanged as needed.
The Musket was originally built for iron sight practice, and used the standard BCM carry handle sight. My plan is to eventually install a fixed low power scope (I haven’t settled on a TA11 or Elcan SpecterOS 4x). But, for now, I want to see how practical it would be on this gun. I also want to see if I can get used to the idea of a magnified optic being behind a fixed FSB, and the “shadow” that the FSB creates. At first, I absolutely hated how the FSB looked in my FOV through the scope, especially at 1x. But the more I’ve practiced, the more usable its become. A lot has been written about the TR24 elsewhere, so I don’t feel the need to write any more about it. I’ve gotten used to the sight picture that includes the FSB, and I have actually found that (at least at 1x) the “floating” FSB actually helps me practice getting consistent cheek and eye position behind the scope. I think my one major draw back is that there might be too much eye relief in a lot of situations. If I am slung up hard, the rifle gets pulled into my shoulder far enough that I have to uncomfortably crane my neck backwards to get proper eye relief. This, of course, can be remedied by pushing the scope a bit further forward in the mount, but it is so situational that I don’t’ think it’s worth the effort.
Why I Did It: Short Action Precision Positional Sling
The TAB sling I was originally using was great for general field use. However, I quickly found that the plastic slider was difficult to tighten enough to stop sliding around when wearing “athletic” type shirts with slick material. Additionally, it was too slow to adjust to proper length for different positions. I substituted a Turner AWS 1907 sling for most of the year. While certainly tight and sticky, the 1907 design was definitely showing its age due to its awkward adjustment method.
The SAP sling consists of two main adjusters. Once you put your arm through the loop, simply pull one of the tabs down to close it tightly around the bicep. Then, a bit forward from that, another pull tab adjusts the tension Here is a video from the creator explaining in better detail.
https://www.youtube.com/watch?v=TqtMEi0ARj8
In all, the Musket has become my favorite AR to shoot. The smoothness of the 20” barrel and rifle gas system is truly a joy to feel. The A5 system adds a lot of practicality to the system. The only drawback I have right now is weight. As pictured, this comes in at 9.2 lbs. It’s still nowhere near the 17 lbs of my M1A, or the 14 lbs of my bolt gun, but it is definitely heftier than my 16” pencil barrel BCM with plastic furniture and RDS.
For purposes of rifle training in the coming year, I am going to consolidate down to just this rifle rather than the two or three I was trying to do this year. I suppose rather than calling it the Designated Marksmanship Training Receiver (DMTR), I will become the Practical Marksmanship Rifle (PMR).
