I’m building an AR-10 from a DPMS L308 lower. The rear takedown spring and detent is kicking my butt!!

This lower doesn’t have the hole behind the retaining plate for the buffer tube. Instead, it has a hole on the inside of the right-hand hole for the pin itself. You have to insert the spring and (somehow) the detent, then slide the takedown pin in.

I’ve tried everything I can think of, but it’s a crazy-tight space to work in. Is there some DPMS trick that I’m missing to make this work?

Thanks!!

Help me understand.
Is it different from this ?

YOUTUBE video

Use a clevis pin.  If it is really as you describe, cut 1/2 of the tip of the clevis in a 90 degree cut on the end bisecting the hole.  Use a pick or tiny screwdriver to set the spring and detent, and then rotate the clevis into place to block the detent and spring.  Push pin into hole as you push out clevis.

Put on some up close glasses and see if a setscrew is blocking the hole.

I am thinking something isn't right with your description.

Yes, completely different! (I wish this forum allowed photo attachments).

Picture the holes for the rear takedown pin. The spring and detent go inside the hole on the right side of the receiver. As you look from the center of the receiver out through the pin hole, there is a vertical hole to drop in the spring and detent. So somehow you have to compress the spring, insert the detent, press it down...then slide the takedown pin in from the right side.

Getting the detent in is the problem. The angle to try to insert from the inside of the receiver is nearly impossible!

Maybe this video will be helpful starts around 4:55. Not sure if your lower is like the video or the one I did.  On mine with the lower on its side I drop the take down pin in groove down first. Then drop the takedown detent in the correct hole. Then drop the selector detent in the correct hole. Then insert the takedown spring in the correct hole. Then insert the selector spring in the grip. Then slide the grip straight up from the bottom compressing the springs against their corresponding detents and install the grip screw.
https://youtu.be/M5t_t7pC3rw

Do you have a set of 'feeler gauges', possibly use a stiff one as a spacer until pin is in position. If not, don't despair.

I'm a basement rookie. Although my old 308LR with A2 stock still competes with my more expensive custom jobs I seldom use it and I've never delt with the dentent.

A Pro, honest to god Pro will be along shortly. These guys can fix your stuff telepathicly.
There is allot of knowledge to be shared and they share it.

Also, if you buy a membership one of the benefits is being able to post pics.

Knew one would be along soon.

Also, I had not thought about some receivers having set screws now.
I better check a few of my own stash!

@j3_ for the win!!

The spring and detent go in above the grip - just like the safety selector spring and detent. I wasn’t expecting it, so I didn’t notice the extra hole (and the grip was already installed).

It took some juggling but I got everything in place!

Thanks!