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Posted: 12/29/2020 10:41:18 PM EST
Built a .45 ACP fed from glock magazines on a New Frontier lower. Runs flawlessly. However, almost all the casings coming out of the gun are all dented flat on the mouth of the casing.


Anybody have any idea what would cause these dented casings? Im thinking they might just be hitting the brass deflector on the upper.
Link Posted: 12/29/2020 11:29:44 PM EST
When you pull the charging handle all the way back, does the bolt disappear? You want to have the bolt stop with about 1/8" of it showing in the ejection port. That may be what is causing the dents in the case mouths.
Link Posted: 12/29/2020 11:53:12 PM EST
Link Posted: 12/30/2020 12:02:52 AM EST
Originally Posted By asdaven:
Built a .45 ACP fed from glock magazines on a New Frontier lower. Runs flawlessly. However, almost all the casings coming out of the gun are all dented flat on the mouth of the casing.
https://photos.app.goo.gl/F8DSBD9CUyKP6FQ49

Anybody have any idea what would cause these dented casings? Im thinking they might just be hitting the brass deflector on the upper.
View Quote


I would get a used brass case that is undamaged and place it into the chamber.

Let the bolt go forward and seat against the brass.

Place a mag loaded with a few rounds into the magwell.

Now slowly pull the charging handle back and watch what happens as the brass is extracted and ejected.

At this point you can verify the bolt stops 1/8" past the bolt catch,. and isn't dragging the empty brass across the mag/bolt catch.

Also....if you are using a standard upper receiver, you might be running out of room with the ejection port and it's catching something on it's way out.
Verify you don't have signs of the brass hitting anywhere around the port.

If this is the issue....get a PCC style upper with the larger port size.



Link Posted: 12/30/2020 5:31:06 AM EST
[Last Edit: 12/30/2020 5:32:12 AM EST by asdaven]
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Mad-Machinist:
What is the weight and overall length of the buffer?
View Quote


The buffer is your .45 ACP buffer. 10.5 oz. I believe.

The upper is a upper reciever specific for .45 ACP.
Link Posted: 12/30/2020 7:57:40 AM EST
Same setup here.  2 quarters in the buffer tube.
Link Posted: 12/30/2020 8:34:20 AM EST
Case deflector most likely, doesn't take that much bolt speed to dent such a large case mouth.
Link Posted: 12/30/2020 11:13:36 AM EST
Im thinking they might just be hitting the brass deflector on the upper.
View Quote


I'm thinking you are on to something
Link Posted: 12/30/2020 11:14:17 AM EST
If this is the issue....get a PCC style upper with the larger port size.
View Quote


Or the Dremel
Link Posted: 12/30/2020 2:50:01 PM EST
[Last Edit: 12/30/2020 2:51:25 PM EST by asdaven]
A spacer along with the extended Macon Armory buffer? The rifle shoots absolutely nice with the heavy Macon Armory buffer. However, compared to my Q Buffer in my 9mm, the Macon Armory one is not as long as it is. My .45 dosent have any bolt open or anything to actuate, so I wonder if it would benefit running as a short stroke setup adding a spacer along with the extended buffer?

Even my 9mm with the even longer Q buffer feels like the bolt throw could be less for the tiny 9mm round.


Thanks-
Link Posted: 12/30/2020 4:04:50 PM EST


Heres the ejection port. It is oversized but brass deflector is machined into it.
Link Posted: 1/5/2021 12:31:03 PM EST
Any ideas? Would adjusting the ejector maybe fix this issue? Gun otherwise runs perfectly.
Link Posted: 1/5/2021 2:25:52 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By asdaven:
Any ideas? Would adjusting the ejector maybe fix this issue? Gun otherwise runs perfectly.
View Quote

Telling you.  Two quarters behind the buffer spring in the buffer tube!
Link Posted: 1/5/2021 3:38:13 PM EST
Discussion ForumsJump to Quoted PostQuote History
Originally Posted By Jetpig:

Telling you.  Two quarters behind the buffer spring in the buffer tube!
View Quote


In addition to the extended buffer?
Link Posted: 1/5/2021 6:23:58 PM EST
I had the problem on my 9mm and 45 acp ARs.

In fact the 300 Blk was doing it too.

I put a Deflector Brake on each and the problem went away.  It was only a couple bucks for each (Amazon).

Maybe there was something mechanical I could have fixed, but everything else was working just fine!
Link Posted: 1/11/2021 11:25:59 AM EST
Tried quarters in the buffer tube and readjusting the ejector. Still got dented cases. I dont know what is causing this.

There is alot of brass marking on the feed ramp on the barrel. But I would think with the bullet still in the casing along with being fired that any dent would be straightened out. Ive played with snap caps and cycling by hand, it is ejecting clear and not hitting anything. My brass deflector does look dinged up though.
Link Posted: 1/13/2021 9:58:50 AM EST
It's been my experience that on that kind of deformation it's the brass deflector. If you could get slow motion video that helps. The strength of the ejection will be a good indicator to start with.
Link Posted: 1/15/2021 10:27:59 PM EST
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