Questions on building an 80% lower AR

[STFU]

I am looking at building a couple of AR platforms from 80% lowers.

I have done a ton of reading on this topic but a few questions come to mind.

Let's start with the billet vs forged:
1) What do the high end Mfg's like DD, Noveske, Spikes, etc use?

Trigger guards:
2) Why are the trigger guards on most forged lowers not complete like they are on the billet lowers?

I see that some sites sell lowers with matching uppers.
3) Is there a reason to pursue this or do most uppers match pretty well?

I know there are a buttload of AR sites out there, any recommendations on ones that focus on building out 80% lowers?

 

[Mr Evilwrench]

I don't think it matters that much what block of aluminum you start with; there are tupperware 80% lowers if you want to make a "Glock" AR, and at that point they start showing weakness where the buffer tube mounts. That's a catastrophic failure

There isn't anything to do with billet/forged that determines the completion of the trigger guard; it's just the way it's made. The "incomplete" trigger guard was the way the original AR15/M16/AR15 were made, to allow the bottom of the trigger guard to drop out of the way so you could fire it with thick gloves or mittens on.

I haven't swapped around truckloads of uppers and lowers, but the tightest fitment I've seen required the tip of the bullet to disengage the pin, vs just poking it with your thumb. The pinhole was originally sized to fit a bullet tip, and that was the specified method for takedown, so it was schwifty.

 

[STFU]

The "incomplete" trigger guard was the way the original AR15/M16/AR15 were made, to allow the bottom of the trigger guard to drop out of the way so you could fire it with thick gloves or mittens on.

Ah, I did not know that was the reason. Thank you for the clarification!

 

[epeery]

I realize this is an older thread, but I thought I would add something for future readers regarding billet vs forged question.

For almost any two dimensionally equivalent widgets made from the same metal, the forged one will be stronger than the billet (machined) one because of the grain structure that results from the two different processes.

I can't speak to what specific manufacturers use, but from the materials / engineering standpoint the forged product is most often the better and more expensive choice. Whether it's worth the cost is completely up to the buyer.

 

[greed]

I am looking at milling out a few 80% lowers. I purchased (waiting for delivery) the 5D Tactical jig which looks fantastic. Question: Has anyone milled out a 308 DPMS Gen2 lower. I am wondering if the trigger box overlaps the nylon screen that is intended to tighten up the slop between upper and lower. Seems like most of the 308 lowers out there are DPMS Gen1, but a few are Gen 2.

 

[mrproc1]

I am looking at building a couple of AR platforms from 80% lowers.

I have done a ton of reading on this topic but a few questions come to mind.

Let's start with the billet vs forged:
1) What do the high end Mfg's like DD, Noveske, Spikes, etc use?

Trigger guards:
2) Why are the trigger guards on most forged lowers not complete like they are on the billet lowers?

I see that some sites sell lowers with matching uppers.
3) Is there a reason to pursue this or do most uppers match pretty well?

I know there are a buttload of AR sites out there, any recommendations on ones that focus on building out 80% lowers?

1- I use the DD Ghost gunner machine, and love it. They make a very nice product and if you have and issues they will spent the time to help you either over the phone or thru email

2- The Ghost gunner is made to use “Mill Spec” lowers, notice some have extended trigger guards.
This won’t allow the lower to sit flush on mill table.

 

[STFU]

1- I use the DD Ghost gunner machine, and love it. They make a very nice product and if you have and issues they will spent the time to help you either over the phone or thru email

2- The Ghost gunner is made to use “Mill Spec” lowers, notice some have extended trigger guards.
This won’t allow the lower to sit flush on mill table.

That is a very nice machine but probably overkill for someone that will only complete a few 80% lowers (like me).
Thank you for the info though.