angryeyebrows
CGN frequent flyer
- Location
- Oscar Mike
I've finally had a chance to get my rifle assembled, after some unforeseeable delays. The original intent was to strip down my AR and swap as many parts over as I could, without incurring too much additional cost. Of course, after building dozens of rifles over the years, I should have known that I would cave and end up buying more parts I didn't REALLY need! Other parts I was simply forced to replace, due to compatibility issues (more on that below). Overall, I'm fairly impressed with the general quality level. The machining looks good to my eyes, and the fit/finish is excellent. Now before getting into what could be perceived as nit picking/#####ing/complaining, let it be known that I'm very thankful to companies like ATRS for making rifles like this a reality in Canada. From a business standpoint, it's an expensive endeavour and with our firearms climate, it is certainly a gamble.
Assembly of the upper receiver group was fairly uneventful. Everything went together as it should. On final assembly, the MRA barrel does make the front end a little heavy for my liking, but I'd rather that, than a super skinny barrel that might not handle a tonne of rounds. This rifle is for training, so maximum reliability is required. Assembly of the lower was less smooth. I tried installing my previous receiver extension/end plate/castle nut combo and found that due to the increased thickness at the rear of the lower receiver, I was not able to screw in my extension enough to capture the buffer detent. My castle nut ran out of room on the extension threads. I believe this was a combined issue of the type of receiver extension (old DD I think) and the slightly thicker Noveske QD end plate. Kind of a pain, but justified the purchase of the excellent PWS ratcheting system, which worked very well. The second issue with assembling the lower was that the pervious bolt that was holding on my BCM pistol grip bottomed out in the ATRS lower, and would not hold the grip tight to the rifle. I tried every old bolt in the tool box, hex head, magpul flat head etc, but none worked. Could have added a washer, but I was intending to try a new grip anyway, so I ordered one and lo and behold, the MOE SL and Magpul's new Dual Drive bolt work perfectly fine. Lastly, when I installed the mil-spec front pivot pin from my old DD lower, I noticed that the pin tip, which usually sticks out the left side a good 1.5 mm or so, was instead recessed. I guess ATRS increased the width at the front of the lower too. It was functional, but a pain in the ass when you can't push it open with just your finger. After some googling, I decided to try the BAD Enhanced Pivot Pin, as they are advertised as having an extended tip. When installed, the pin is about flush, but can be still be pushed/pulled out without a tool. On the right side, there is a slight gap (pic below) where is looks as though the pin could close more, but the little retaining detent has run out of track. When compared to a normal AR lower, the hole in the lower receiver for the detent and spring appears slightly further outward, preventing the shoulder of the pin from closing against the side of the lower. If it could fully close to the proper position the BAD pin would be perfect for the thicker ATRS receiver. Perhaps I can modify the pin.
Once the rifle was fully assembled, and just with some dry drills, I noticed some other areas that will need to be addressed, and some that may or may not be possible to fix. In no particular order:
The sharp front mag well profile - I occasionally grab the rifle at the mag well for shooting in certain positions, but I have found that I quite often handle the rifle by the mag well when I'm not shooting. I don't know why ATRS profiles the front lip of the mag well with such an aggressive edge, but it's going to be zipped off in short order. I thought perhaps it wasn't as sharp in person as it looked in pics, but I was mistaken. Maybe this won't bother some people, but it annoys the hell out of me, so it'll be address. (pic below)
The fence around the mag release - As what seems to be purely a design choice, this area has a very square profile, compared to the standard AR fence. I found that I am constantly hitting the tip of my finger on the fence which forces me to consciously reposition to press the button cleanly. If you have stubby little digits, maybe not an issue. If you have normal sized hands, and are very used to the feel of that button, it might put you off.
The rear of the trigger guard - The machined in trigger guard is nice, but right at the rear there are two tiny points that you might notice when supporting the rifle with just the pistol grip hand, and not wearing gloves. Minor, and will be cleaned up when I get the mag well fixed. (pic below)
The curved profile at the back of the lower - This is also minor, but if you have a pistol grip with a beaver tail, you might have a substantial gap there. It's a little ugly, but functional. (pic below) ***EDIT*** So far this appears to be the case with the Magpul MOE SL. I swapped it out for my old BCM Gunfighter Mod 3 which DID need a washer due the lack of depth in the hole for the grip screw. Overall, the beaver tail on the BCM grip is far better fitting, and the little duck bill that stick out over the back of the tigger guard covers the two sharper points mentioned above.
Relocated charging handle cutout - This may or may not be a deal breaker for me. Once I have a few hundred rounds or so through it and had a chance to do some proper drills, I will know for sure. If you have training you will know that when clearing particular malfunctions, you will pull the charging handle fully to the rear, depress the bolt catch, locking the bolt to the rear, and return the charging handle forward. When you try and return the charging handle forward, it will fight you a little, as the little tabs on the sides of the handle happen to be located right at the cutout in the track inside the upper. I'm hoping some other MS owners will be able to check this out and see if it's an issue with just my set up, or with all of them. Either way I don't like it, and I'll need to see if I can come up with a fix.
My final list parts is as follows and I've noted the parts that were new purchases:
- MRA 18.6" .223 Wylde Barrel with Straight Flutes, Nitrided Black (New)
- 15" BCM MCMR (New)
- Colt Canada Bolt Carrier Group
- Rainier Low Profile Gas Block (New)
- Raptor Charging Handle
- Troy BUIS
- DD Flash Suppressor
- DD LPK
- Geissele Maritime Bolt Catch (New)
- Geissele SSA
- BAD Enhanced front Pin (New)
- PWS Enhanced Receiver Extension (New)
- Colt H Buffer
- B5 Systems Sopmod Bravo Stock
- Magpul MOE SL Grip (New) Replaced with BCM Gunfighter Grip MOD 3
- Seekins Precision Magazine Button
- BAD Ambi Selector
- Gear Dynamics Quick Adjust Sling (Of course!)
Now for the pictures, because everyone loves pictures:
Take Down Pin (Front Pivot Pin Gap)
Sharp Points
Grip Gap
Completed Rifle
Assembly of the upper receiver group was fairly uneventful. Everything went together as it should. On final assembly, the MRA barrel does make the front end a little heavy for my liking, but I'd rather that, than a super skinny barrel that might not handle a tonne of rounds. This rifle is for training, so maximum reliability is required. Assembly of the lower was less smooth. I tried installing my previous receiver extension/end plate/castle nut combo and found that due to the increased thickness at the rear of the lower receiver, I was not able to screw in my extension enough to capture the buffer detent. My castle nut ran out of room on the extension threads. I believe this was a combined issue of the type of receiver extension (old DD I think) and the slightly thicker Noveske QD end plate. Kind of a pain, but justified the purchase of the excellent PWS ratcheting system, which worked very well. The second issue with assembling the lower was that the pervious bolt that was holding on my BCM pistol grip bottomed out in the ATRS lower, and would not hold the grip tight to the rifle. I tried every old bolt in the tool box, hex head, magpul flat head etc, but none worked. Could have added a washer, but I was intending to try a new grip anyway, so I ordered one and lo and behold, the MOE SL and Magpul's new Dual Drive bolt work perfectly fine. Lastly, when I installed the mil-spec front pivot pin from my old DD lower, I noticed that the pin tip, which usually sticks out the left side a good 1.5 mm or so, was instead recessed. I guess ATRS increased the width at the front of the lower too. It was functional, but a pain in the ass when you can't push it open with just your finger. After some googling, I decided to try the BAD Enhanced Pivot Pin, as they are advertised as having an extended tip. When installed, the pin is about flush, but can be still be pushed/pulled out without a tool. On the right side, there is a slight gap (pic below) where is looks as though the pin could close more, but the little retaining detent has run out of track. When compared to a normal AR lower, the hole in the lower receiver for the detent and spring appears slightly further outward, preventing the shoulder of the pin from closing against the side of the lower. If it could fully close to the proper position the BAD pin would be perfect for the thicker ATRS receiver. Perhaps I can modify the pin.
Once the rifle was fully assembled, and just with some dry drills, I noticed some other areas that will need to be addressed, and some that may or may not be possible to fix. In no particular order:
The sharp front mag well profile - I occasionally grab the rifle at the mag well for shooting in certain positions, but I have found that I quite often handle the rifle by the mag well when I'm not shooting. I don't know why ATRS profiles the front lip of the mag well with such an aggressive edge, but it's going to be zipped off in short order. I thought perhaps it wasn't as sharp in person as it looked in pics, but I was mistaken. Maybe this won't bother some people, but it annoys the hell out of me, so it'll be address. (pic below)
The fence around the mag release - As what seems to be purely a design choice, this area has a very square profile, compared to the standard AR fence. I found that I am constantly hitting the tip of my finger on the fence which forces me to consciously reposition to press the button cleanly. If you have stubby little digits, maybe not an issue. If you have normal sized hands, and are very used to the feel of that button, it might put you off.
The rear of the trigger guard - The machined in trigger guard is nice, but right at the rear there are two tiny points that you might notice when supporting the rifle with just the pistol grip hand, and not wearing gloves. Minor, and will be cleaned up when I get the mag well fixed. (pic below)
The curved profile at the back of the lower - This is also minor, but if you have a pistol grip with a beaver tail, you might have a substantial gap there. It's a little ugly, but functional. (pic below) ***EDIT*** So far this appears to be the case with the Magpul MOE SL. I swapped it out for my old BCM Gunfighter Mod 3 which DID need a washer due the lack of depth in the hole for the grip screw. Overall, the beaver tail on the BCM grip is far better fitting, and the little duck bill that stick out over the back of the tigger guard covers the two sharper points mentioned above.
Relocated charging handle cutout - This may or may not be a deal breaker for me. Once I have a few hundred rounds or so through it and had a chance to do some proper drills, I will know for sure. If you have training you will know that when clearing particular malfunctions, you will pull the charging handle fully to the rear, depress the bolt catch, locking the bolt to the rear, and return the charging handle forward. When you try and return the charging handle forward, it will fight you a little, as the little tabs on the sides of the handle happen to be located right at the cutout in the track inside the upper. I'm hoping some other MS owners will be able to check this out and see if it's an issue with just my set up, or with all of them. Either way I don't like it, and I'll need to see if I can come up with a fix.
My final list parts is as follows and I've noted the parts that were new purchases:
- MRA 18.6" .223 Wylde Barrel with Straight Flutes, Nitrided Black (New)
- 15" BCM MCMR (New)
- Colt Canada Bolt Carrier Group
- Rainier Low Profile Gas Block (New)
- Raptor Charging Handle
- Troy BUIS
- DD Flash Suppressor
- DD LPK
- Geissele Maritime Bolt Catch (New)
- Geissele SSA
- BAD Enhanced front Pin (New)
- PWS Enhanced Receiver Extension (New)
- Colt H Buffer
- B5 Systems Sopmod Bravo Stock
- Magpul MOE SL Grip (New) Replaced with BCM Gunfighter Grip MOD 3
- Seekins Precision Magazine Button
- BAD Ambi Selector
- Gear Dynamics Quick Adjust Sling (Of course!)
Now for the pictures, because everyone loves pictures:
Take Down Pin (Front Pivot Pin Gap)
Sharp Points
Grip Gap
Completed Rifle
Last edited:


















































