Abmormal wear on CMMG Banshee .45acp upper

[oregunbob541]

A little backstory... I purchased a CMMG Banshee in .45acp a couple months back. My first trip to the range I found it would FTF and FTE every 2 or 3 rounds regardless of which mag I was using. I sent it to CMMG and they replaced the BCG, added a magwell shim and sent it back about a month later. I took it out and put 100 rounds through it and it finctioned flawlessly. While cleaning it at home that afternoon, I noticed some unusual wear by the brass deflector. It looks like the spent casings are causing some serious damage to the upper, especially for only having 200 rounds fired total while I've owned it. I have 8-900 rounds through my 9mm banshee and it shows none of this wear whatsoever. Check out the pics.... what do you guys think? Is this acceptable?

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[oregunbob541]

Here is the response frkm CMMG... I find it hard to believe that normal use causes this type of wear this fast on a $1500 firearm. I have several AR platform guns and have never seen this type of wear before...

 

[Alexx1401]

since it's just brass that's hitting I take it there is just coating being rubbed off? If it was me? May try relieving some of that area if it bothered me seeing the coating gone. Then paint the area with something to test. If it no longer is causing the rub you can get the thing coated again. It is kind of sucky that on a gun that pricey it's doing that. Will they take it back?

 

[aksu747]

Here is the response frkm CMMG... I find it hard to believe that normal use causes this type of wear this fast on a $1500 firearm. I have several AR platform guns and have never seen this type of wear before...

Yes but are any of those other AR's you have pistol caliber besides this one?
I ask because this is fairly normal for pistol caliber AR's that is why the Colt 9mm SMG pictured below came from the factory with an extended brass deflector.

 

[drstrangelove]

I would stop the metal erosion with a nice overlay of JB Weld on that spot.

 

[Vrod]

Im not an expert but seems to me a flaw in the design. Those shell casings are going to hit that flat spot pretty hard. My Alexander Arms and Diamondback AR's have a slanted brass deflectors much closer to the port opening with a very small flat area but still causes some scuffing on the surface. A flat spot that size is going to take a pounding.

 

[Greenbug]

Apply a piece of the sticky backed velcro strip to that area of your receiver. Use the soft "loop" side of the velcro tape and replace when needed. It should protect the finish quite well.

 

[2A2Dend]

To me it's out of timing. If you "built" said pistol, something like what you have going on, would need diagnosed and remedied, but this should not be the case.
You buy a complete "name brand" like CMMG to "not" be in the situation you're in currently.
I would send it back for replacement, or refund and move on.
CMMG is not cheap.

 

[Unicykle]

You could always just put a piece of something like the black rubber flex tape or a small piece of a Talon grip tape over it and change the tape out every few thousand rounds or as needed?

 

[oregunbob541]

Yes but are any of those other AR's you have pistol caliber besides this one?
I ask because this is fairly normal for pistol caliber AR's that is why the Colt 9mm SMG pictured below came from the factory with an extended brass deflector.View attachment 708660

I have a CMMG Banshee in 9mm as well. I've put about 900 rounds through it and it shows absolutely none of this wear.

 

[oregunbob541]

since it's just brass that's hitting I take it there is just coating being rubbed off? If it was me? May try relieving some of that area if it bothered me seeing the coating gone. Then paint the area with something to test. If it no longer is causing the rub you can get the thing coated again. It is kind of sucky that on a gun that pricey it's doing that. Will they take it back?

I'm less concerned about the cerakote being worn away than I am about the aluminum upper being damaged by the ejected brass. If you look closely in the photos you can see a couple spots where the metal is getting dinged up pretty good. and remember there are only 200 rounds through it.

 

[Member 34319]

It's normal. CMMG does not have a fixed ejector. It has a plunger like that of a regular AR-15. The plunger simply puts pressure on one side of the case as it travels reward. Once it gets to the ejection port, it is still held into place by the extractor, kind of just sticking out of the ejection port riding along backwards until it hits something. That something is that spot you have in your picture.

You can always get an brass deflector protector. Which is kind of silly considering that's what the brass deflector is technically for.

AR-15 Shell Deflector Protector

AR16/M16 Shell Deflector Protector. I have been asked by many to make a shell deflector cover to keep from pitting their shell deflector when shooting. This is milspec anodized aluminum and will take the brass marks and dings that your shell deflector normally would. It is removable so when it...

carolinalaserworks.ecwid.com

 

[oregunbob541]

That shell deflector protector wouldn't actually cover the area thats getting damaged on my banshee.

 

[Member 34319]

As for the aluminum, I ensure you the forged aluminum receiver is much harder than the brass cases hitting it.

If anything the cases are shot peening the aluminum which would make it harder.

 

[Member 34319]

Here is the response frkm CMMG... I find it hard to believe that normal use causes this type of wear this fast on a $1500 firearm. I have several AR platform guns and have never seen this type of wear before...

View attachment 708656

AR15

 

[oregunbob541]

There are already a couple of chips in the aluminum upper. That's what I'm concerned about...not the cerakote wear. Look closely at the photos, around the ejection port..

 

[Member 34319]

Normal wear. Guns do not stay super pretty their whole life. That area of the receiver is thick aluminum it's not going to crack or break. Cosmetics only. If you don't like it, don't shoot it.

9mm. Mine's basically bare aluminum now. Roughly estimated 15000 rounds or more.

 

[Member 34319]

If you don't like that wear, please don't look at the cam pin wear inside the receiver. Also normal wear. Thankfully CMMG uses a round cam pin at least!

 

[oregunbob541]

it is deforming the aluminum already. there is a decent size raised burr. it's not just cerakote wear. You say you have 15k rounds down the pipe... I have 200

 

[oregunbob541]

The lower circle shows a little sharp deformed piece of aluminum hanging over the edge