ACR vs. SCAR: Part I

[MilitaryArms]

I am doing an in-depth comparison of the ACR and the SCAR. I'm shooting a multi-part series for this comparison and I just completed Part I.

[ame=http://www.youtube.com/watch?v=kYNlGHjZxnY]YouTube - ACR vs SCAR Part I[/ame]

Questions and comments are welcome.

 

[shooter521]

"Where does he get all those wonderful toys?"

Nice walkthrough on the ACR; looking forward to future installments. I have handled both the ACR and the SCAR and have shot the latter. An ACR is on my short list to get this year.

In the example we had in the shop last year, I noticed that the inside of the upper receiver did not appear to be finished (it was silver/gray rather than brown); is this the case with your test article, as well?

 

[MilitaryArms]

Yes, the finish is mostly non-existent inside the upper. I'm assuming this is normal.

I know they nitrite finish the barrels, so I wonder if they do the same to the receiver.

 

[shooter521]

Yes, the finish is mostly non-existent inside the upper. I'm assuming this is normal.

Wonder if it's the same way on the black ones? My first thought was that the black receivers are anodized (so it should be black inside and out) while the brown ones are painted. Never thought about the receivers being nitrided or "clear-coated".

 

[MilitaryArms]

I'm thinking it is nitrited and that's why the unfinished parts have that unique color. That's what a Tenifer treated slide looks like before it's covered with a finish.

 

[Shooter1]

Well the ACR stock folded and being loose isnt a big deal since its only a storage thing ya know. Very nice part 1!

 

[Michld01]

Good job! Thanks for you effort.

 

[223 Gunner]

Very well done as always. Thanks for part 1, looking forward to the rest of the series.

 

[Lock n Load]

Good info, Im still wanting an ACR.... or two !!!

 

[MilitaryArms]

I found this posted on AR15.com by Bushmaster in the partner area.

4th Chrome lined vs. New Proprietary Coating: Many have pointed out that the ACR barrels are not chrome lined and that is correct... They are not. That does not mean that they are not coated. As stated in our original press release the ACR barrels, and all internal components, feature a new, proprietary coatings that are substrate conversions which vastly increase durability, lubricity and reliability.

This would lend some credibility to the notion the internals are in fact nitrited, or utilize some other finish.

They also mentioned plans to release a 7.62x39 conversion after the 6.8, which is already announced.

 

[MilitaryArms]

There are some little quirks with the ACR.

I broke the clip that holds the pistol grip compartment in the grip. It just snapped off while trying to figure out why it wouldn't stay locked in place. It's not fit properly, the dimensions for are off somewhere. Others have reported a similar issue on AR15.com with their storage compartments.

Then there's the little rubber o-ring that holds the firing pin retainer pin in place. It doesn't fit right, either. Others report this problem with their rifles on the Bushmaster forums on AR15.com as well. You basically have to use a hammer to pound it in to seat so it won't prevent you from reassembling your rifle. Here's what the pin looks like with the o-ring mounted and in the carrier. When it's like this, you rarely can reassemble the rifle as the carrier won't fit into its rails.

Here's the culprit.

Once you remove the o-ring...

The retainer pin fits below flush and the rifle can be easily assembled.

The owners manual says it's safe to fire the rifle without the o-ring but it says to replace it if its damaged or missing. I'm not sure if I will start to see damage to the pin or pin hole with the o-ring removed.

The sling mount points just leave you scratching your head. I love the idea of quick detach mounting points on the rifle. But their location and the fact one point doesn't have the quick detach but instead uses a traditional loop mounting point makes you wonder what the engineers at BM were thinking.

Here's the single loop mounting point, and probably the point that most users would want to use at some point.

The sling mounting point on the rear of the stock only exists on the left side of the rifle. What you would think is a mounting point on the right side of the butt stock isn't, it's just a screw hole holing the mount for the left side of the rifle.

If you fold the stock and have your sling attached to this rearward point on the butt stock, you can't use the sling anymore as the stock doesn't lock in the folded position. I will either snap back open as you walk around or the rifle will flop around with the muzzle wanting to point up in the air. Here's what it looks like with the sling mounted to both forward mounting points with the stock folded.

Keep in mind the stock doesn't lock in the folded position... strange.

The gas regulator is marked U and S. This stands for "Suppressed" and "Unsupressed". If you move it to the "Suppressed" setting, it basically turns the gas completely off as there's no hole in the regulator for this setting. There's nothing in between. On the SCAR you have high and low cycle so you can adjust your gas system for different types of ammo and conditions (like if the rifle is dirty). Not so with the ACR. There is another regulator I've seen floating around that's marked "H" and "L" but you have to call up Bushmaster and tell them you're having problems with your rifle cycling 5.56mm ammo before they'll send it to you. The H stands for "high pressure" or 5.56mm ammo, and the L stands for "low pressure" or .223 ammo.

The last thing that I find odd is the selector lever. For me, the ambi-lever is located in a bad position. Even though it's a relatively small lever, I always hit my index/firing finger when trying to disengage the safety to fire. Once it's disengaged, my index finger rides on top of the bottom end of the lever which becomes uncomfortable during extended shooting as the lever digs into your finger.

I'll cover these quirks in a future installment video, but I thought I would share them with you guys before I have a chance to put that video together.

 

[jblomenberg16]

If the lower isn't serialized on the ACR, which component is serialized and considered to be the firearm by the ATF? In on of the pictures it looks as if the upper reciever is marked "caliber-multi." Does that mean the upper is the firearm in the eyes of the ATF?

 

[shooter521]

The sling mounting point on the rear of the stock only exists on the left side of the rifle. What you would think is a mounting point on the right side of the butt stock isn't, it's just a screw hole holing the mount for the left side of the rifle.

If you unscrew the screw, is the QD socket reversible to the right side, like on the Magpul ACS stock? I wouldn't use the folding feature of the stock for anything but storage and transport, but I have become fond of attaching my sling at the right rear of the stock, and at the left front of the receiver.

Does that mean the upper is the firearm in the eyes of the ATF?

Yes. This allows Bushmaster (or Magpul, or whoever) to make different lowers to accept different mag styles (AK, for example) or with different features (removable grip) or of different materials (Remington prototype alloy lower) and just sell them as parts.

 

[223 Gunner]

Wow after the small list of flaws I'm quickly loosing interest in an ACR, I may have to go the SCAR route and buy both of the SCARS. Back in the '80's and 90's people did that with HK 91 and 93's.
Times have changed!

 

[MilitaryArms]

If the lower isn't serialized on the ACR, which component is serialized and considered to be the firearm by the ATF? In on of the pictures it looks as if the upper reciever is marked "caliber-multi." Does that mean the upper is the firearm in the eyes of the ATF?

Yup, the upper is the "firearm" in the eyes of the ATF. This is true for both the ACR and SCAR. It seems back in the day, the ATF considered the part of the rifle that housed the magazine to be the firearm. The AR15's lower for example or in the case of the FAL, the upper which also mounts the magazine. It seems that requirement has changed.

 

[MilitaryArms]

If you unscrew the screw, is the QD socket reversible to the right side, like on the Magpul ACS stock? I wouldn't use the folding feature of the stock for anything but storage and transport, but I have become fond of attaching my sling at the right rear of the stock, and at the left front of the receiver.

It would appear you can reverse the mounting point in the rear, although I haven't tried it yet. There is a traditional loop sling attachment point at the rear of both rifles, although I do find the location of the ACR's (at the bottom) to be a bit odd. Given the location of the quick detach points, if used, the sling mounting point at the bottom of the stock would cause the rifle to want to naturally hang up-side-down.

ACR:

SCAR:

 

[Dtruck260]

For the "O" ring issue,

place the ring in the carrier first, then push the pin in,

I do it that way and it slips into position properly, any other way and I get the raised pin like you show.

Other then that, I have had no issues with my ACR, (about 1400rds, wolf mostly)

Folding stock not an issue for me, I only store it that way

 

[MilitaryArms]

For the "O" ring issue,

place the ring in the carrier first, then push the pin in,

I do it that way and it slips into position properly, any other way and I get the raised pin like you show.

I'll be darned, that works like a charm. Thank you. While it's obviously not intended to be done this way, it makes putting it back together with the o-ring possible.

 

[Dtruck260]

I do agree its odd to have todo that, but not the first time I have passed this info along to another ACR owner, but hey, it works

 

[MilitaryArms]

Here's some more info.

SCAR weight: 7.2lbs

ACR weight: 8.4lbs