Current Cerro Lower Receiver Forgings

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[ARCHIVED THREAD] - Current Cerro Lower Receiver Forgings

Posted: 12/4/2020 5:03:06 PM EDT

Like a lot of people here, I was less than thrilled by Cerro changing their lower receiver forging to this.

First, it means I can't re-contour an A2 into an A1. Second, it limits the number of clones I can make of rifles from the early 2000s. What we're left with from the new style forging is late M16A4s and M4A1s.
That could be okay, except the commercial forging is not exactly like the military one. The mag fence is a little different. Uncle Sam gets the mag fence we're all used to; we get an odd, very pointed fence.
Anyway, I wanted to see if I could make this point a little more normal, so I broke out the mini files and sandpaper. This is the result.
Before:

After: (I media blasted the side of the mag well)

Here is a comparison side-by-side. (Or, top-to-bottom)

I think I can live with this.

Posted: 12/4/2020 8:41:49 PM EDT

[#1]

Getting ready to change into someone more comfortable. Name changes coming.

Posted: 12/4/2020 10:31:19 PM EDT

[#2]

True. But, most clones would be black. So, after getting anodized, that could later be filled with JB Weld and touched up.

Posted: 3/20/2021 1:07:19 AM EDT

[#3]

A little more progress on one of my late Cerro lowers. I milled from 80 to 100%, and marked it with stencils. (Couldn't do anything about the selector font sizes)

Posted: 3/20/2021 9:18:05 AM EDT

[#4]

Great job!

Posted: 3/20/2021 3:03:51 PM EDT

[#5]

So far, I have just done these with that forging:

Attached File

But it seems that M4s have been spotted in the wild with all types of forgings:

Attached File

Posted: 3/20/2021 10:59:03 PM EDT

[#6]

@HDrider
Thanks!

@HenryKnoxFineBooks
Great looking lowers!

Quote History

But it seems that M4s have been spotted in the wild with all types of forgings:

View Quote

Yes...M4s and early M4A1s have used at least three different forgings. But I have only seen this Cerro forging used on late M4A1s and late M16A4s.

Posted: 7/4/2021 4:52:20 PM EDT

[#7]

A little update. Here is the 2nd of my two new Cerro forgings; this one as an A4.

I also reworked the point in the reinforcing on the right side.

They're now ready to go to the anodizer.

Posted: 7/4/2021 5:14:59 PM EDT

[#8]

Can I ask about the receiver extenstion "wings" (for lack of a better word) and why they're different from the A2 style lowers? Are these "sloped" areas what newer M4's and M16A4's have?

Attached File

Posted: 7/4/2021 5:16:10 PM EDT

[#9]

that rear sloped change in the forging has actually been seen a bunch on Prop of US govt FNs.

Posted: 7/4/2021 5:28:27 PM EDT

[#10]

Attached File

Posted: 7/4/2021 7:05:22 PM EDT

[#11]

Quote History

Quoted:
Can I ask about the receiver extenstion "wings" (for lack of a better word) and why they're different from the A2 style lowers? Are these "sloped" areas what newer M4's and M16A4's have?

https://www.ar15.com/media/mediaFiles/274532/InkedwgBfoMD_LI_jpg-2001780.JPG

View Quote

To answer your last question first...Yes, the latest M16A4s and M4A1s have these sloped reinforcements at the rear of the lower receiver.

A few years ago, one of the main forging companies, Cerro Forge, changed their dies for the lower receiver.

Posted: 7/5/2021 2:21:29 AM EDT

[#12]

Quote History

Quoted:
A little update. Here is the 2nd of my two new Cerro forgings; this one as an A4.
https://i.imgur.com/ouYLrxp.jpg
I also reworked the point in the reinforcing on the right side.
https://i.imgur.com/wgBfoMD.jpg
They're now ready to go to the anodizer.

View Quote

Nice work reprofiling the fence. Shame that so many of these 80%'s come with that giant bubble letter FIRE/SAFETY marking.

Posted: 7/5/2021 9:41:56 AM EDT

[#13]

Most low cost engraving solutions seem to do only 1/8 inch which is too large, or 1/16 which is too small. have to go up to CAD or laser engraver to get anything close to the .1 or .094 we want for .mil clones and there is a learning curve associated with that. Some guys work around that with etching - but that has its own issues with quality of the end result.

Posted: 7/6/2021 9:51:22 AM EDT

[#14]

Quote History

Quoted:

Nice work reprofiling the fence. Shame that so many of these 80%'s come with that giant bubble letter FIRE/SAFETY marking.

View Quote

Thanks for the compliment. That and the giant lettering were my big issues with these two lowers. At least they were marked "SEMI" instead of "FIRE".

Posted: 7/6/2021 10:00:05 AM EDT

[#15]

Quote History

Quoted:
Most low cost engraving solutions seem to do only 1/8 inch which is too large, or 1/16 which is too small. have to go up to CAD or laser engraver to get anything close to the .1 or .094 we want for .mil clones and there is a learning curve associated with that. Some guys work around that with etching - but that has its own issues with quality of the end result.

View Quote

These two were etched. Getting it to look right takes practice and some experimentation. The big issue with etching is depth. Measuring it is near impossible. I'm a little anxious to see how these look after anodizing.

Posted: 8/18/2021 1:58:13 AM EDT

[#16]

Nice

Posted: 8/19/2021 10:32:29 AM EDT

[#17]

Quote History

Quoted:
@HDrider
Thanks!

@HenryKnoxFineBooks
Great looking lowers!

Yes...M4s and early M4A1s have used at least three different forgings. But I have only seen this Cerro forging used on late M4A1s and late M16A4s.

View Quote

#489 courtesy of @Combat_Diver which clearly has the early Cerro forging

Attached File

Posted: 8/19/2021 3:41:30 PM EDT

[#18]

Quote History

Quoted:

#489 courtesy of @Combat_Diver which clearly has the early Cerro forging

https://www.ar15.com/media/mediaFiles/180398/489_JPG-2058257.JPG

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:
@HDrider
Thanks!

@HenryKnoxFineBooks
Great looking lowers!

Yes...M4s and early M4A1s have used at least three different forgings. But I have only seen this Cerro forging used on late M4A1s and late M16A4s.

#489 courtesy of @Combat_Diver which clearly has the early Cerro forging

https://www.ar15.com/media/mediaFiles/180398/489_JPG-2058257.JPG

That's obviously an old Colt M16A2 that was rebuilt into an M4A1. The "BURST" was X'ed out and "AUTO" stamped beneath it. The forging itself is a Type 1 Colt specific (look at the radius under the pivot pin, and the split spring tube in the rear), and not Cerro. Balimoy also used this forging. The UID sticker has the Cage Code 19207, which is the Army Tank Automotive Command (TACOM), which is responsible for weapons overhauls.

Posted: 8/20/2021 11:07:08 AM EDT

[#19]

Quoted:

That's obviously an old Colt M16A2 that was rebuilt into an M4A1. The "BURST" was X'ed out and "AUTO" stamped beneath it. The forging itself is a Type 1 Colt specific (look at the radius under the pivot pin, and the split spring tube in the rear), and not Cerro. Balimoy also used this forging. The UID sticker has the Cage Code 19207, which is the Army Tank Automotive Command (TACOM), which is responsible for weapons overhauls.

View Quote

Our M4A1s had exactly the same remarks as well as other styles using stamps instead of engraving. They were M4 Carbines converted to M4A1(2015-2020, Fort Campbell)

Posted: 8/20/2021 12:13:03 PM EDT

[#20]

Quote History

Quoted:

That's obviously an old Colt M16A2 that was rebuilt into an M4A1. The "BURST" was X'ed out and "AUTO" stamped beneath it. The forging itself is a Type 1 Colt specific (look at the radius under the pivot pin, and the split spring tube in the rear), and not Cerro. Balimoy also used this forging. The UID sticker has the Cage Code 19207, which is the Army Tank Automotive Command (TACOM), which is responsible for weapons overhauls.

View Quote

Attached File

SN should date it to the last half of 1995.

Posted: 8/20/2021 8:31:04 PM EDT

[#21]

Quote History

Quoted:

https://www.ar15.com/media/mediaFiles/180398/m4colt489_JPG-2059549.JPG

SN should date it to the last half of 1995.

View Quote View All Quotes

View All Quotes

Quote History

Quoted:

Quoted:

That's obviously an old Colt M16A2 that was rebuilt into an M4A1. The "BURST" was X'ed out and "AUTO" stamped beneath it. The forging itself is a Type 1 Colt specific (look at the radius under the pivot pin, and the split spring tube in the rear), and not Cerro. Balimoy also used this forging. The UID sticker has the Cage Code 19207, which is the Army Tank Automotive Command (TACOM), which is responsible for weapons overhauls.

https://www.ar15.com/media/mediaFiles/180398/m4colt489_JPG-2059549.JPG

SN should date it to the last half of 1995.

Wow! That's an early M4, and with a Type 1 forging! I never would have expected that...maybe a Type 3, yes.

Posted: 10/26/2021 11:14:34 AM EDT

[#22]

I picked up my two lowers from a local anodizer last Friday. More Photos coming soon.

Here's my black M16A4 lower with Mueller grey upper (with a little oil on both)

Posted: 10/30/2021 8:10:27 PM EDT

[#23]

Quote History

Quoted:
I picked up my two lowers from a local anodizer last Friday. More Photos coming soon.

Here's my black M16A4 lower with Mueller grey upper (with a little oil on both)
https://i.imgur.com/C4gZ0Hz.jpg

View Quote

Who did the anodizing?

Posted: 11/1/2021 8:59:22 AM EDT

[#24]

@wtwining

PM sent

Posted: 1/14/2022 5:27:45 PM EDT

[#25]

I forgot I hadn't posted my other receiver after it came back from the anodizer. This, with a Brownells M4 upper.

Posted: 1/15/2022 3:43:22 PM EDT

[#26]

Quote History

Quoted:
I forgot I hadn't posted my other receiver after it came back from the anodizer. This, with a Brownells M4 upper.
https://i.imgur.com/IMhbrpI.jpg

View Quote

That looks really nice. My OCD brain is getting hung up on the FN rollmark you chose, though. Isn't that the FN America civi mark instead of the FNMI .mil mark?

Posted: 1/17/2022 1:02:41 PM EDT

[#27]

Quote History

Quoted:

That looks really nice. My OCD brain is getting hung up on the FN rollmark you chose, though. Isn't that the FN America civi mark instead of the FNMI .mil mark?

View Quote

FN has been using that mark on M4A1s

Attached File

And so I did, too.

Attached File