Kirk at Aero Precision walks us through what that little black 4-40 Set Screw in your Lower Parts Kit is for, and how to install it in your Aero Precision Lower Receiver.
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Sure wish y’all would include this and the bolt catch screw in the box with your lowers since y’all include the nylon tipped tension screw with them. That being said, is this detent screw just an optional convenience part? Will the takedown pin detent function without it?
I just purchased an M5 lower along with the lower kit…. is the installation the same on my M5?…. I do understand the 4-40 screw is on the bottom but do cut the spring just like this video shows, is the process the same?
Ok so how did i not know this till now? So i have to buy the Aero LpK to get the screw? 🤔 Never knew this existed
Dumb question but how do you get the takedown pin open to connect the upper? I have 2 complete lowers and uppers and i cant get them connected. Its all aero precision parts as well.
Thanks
Glad I found this video, but why are there no instructions provided with the lower parts kit or the lower itself? I struggled for an hour trying to get the set screw in and lost the spring and the set screw multiple times having to hunt for them. I'm amazed I was able to find them each time. At the very least it would be helpful to provide a QR code or web address with different parts to info that a builder would need. Additionally, I think it would be nice to provide a properly sized extra spring in the kit.
So u have to use a aero LPK if u buy an aero lower??
Man my spring doesn’t fit lol
Curious if those set screws are made from a ferrous metal
I've already installed mine but I did not trim the spring. Is that too much pressure on it?
In the real world, this should be a 30 minute video, 3 minutes for the actual installation and 27 minutes looking for the 4-40 set screw that got launched when trying to screw it in.
I have done this to all my lowers. Although none are this brand. Simply buy a bag of 4-40 set screws and a 4-40 tap. Carefully tap the detent hole and cut spring as shown here and install as shown here. I must say it is nice to have it already tapped though, I'm always afraid I'm going to break my tap off in the hole and ruin the lower. So if you do this use lube and take it slow and easy. Thanks for the video.
I have a ton of those tiny set screws I had no idea what they were for. Good to know, thanks.
The M5 has the spring coming out towards the grip. Why not tap it 4-40 also?
So I have the m5 lower parts kit and only have the 4-40 screw and a roll pin left after assembly. In the back next to where the buffer tube would go, my lower doesn’t have a spot to insert the screw. So where does mine go?
Does this apply to the x15 aero lower?
AP- WTF, why don’t you include instructions in the Lower Parts kit if the Springs need to be trimmed to fit. Or better yet for $40, AP should cut the Springs to the correct size. I wasted 20 minutes trying to get the rear spring to fit before checking YouTube.
Please include a .050” hex key in the kit!
Is this the same for the m5 lowers?
What a great idea! Saves another spring flying across the room never to be found again. Love AP!
What are the exact dimensions of this screw to help purchase separately?
Does hole have to have threads
Why do you make the spring that long if you have to trim it?
Just ordered the M4E1 Enhanced 16" 5.56 Mid-Length Complete Upper. That’s going to go along with the M4E1 Lower. With a Geissele SSP trigger. Can’t wait to take her to the range!
How long is the screw?
ha, my last build I didn't trim the spring. might have made it easier lol
I was today years old when I found out what that was for. And I've been using aero for years! Hahahaha!!!! The rear has never been an issue for me, but the front pivot pin..well…
Now that makes much more sense!
Absolutely thrilled to see you putting this out there. I was struggling before I found another youtube video recommending the trimming of the spring. This is a much more forthright and clear description.
I'm using Juggernaut Tactical Hellfighter kits because I'm in California, and this is especially crucial since that takedown pin needs to rotate to function properly. Also the JT takedown pin has cutaway sections and too much tension on the detent can really push the pin out of place.
Thank you Aero Precision for such excellent products. I am loving the 3 different calibers I have built so far.
Man that's slicker than snot!
are your parts kit labeled so people know what it is
I thought this 4-40 take-down pin set screw was only on the M4e1?! I would check my Gen II DTOM and FDE lowers but I stated my castle nuts and don't want to take em off to check. Yet another reason to love Aero parts!
Cut the spring!?…uggh! I lost my screw trying to press the spring in. I thought I had it seated into the threads and the spring torpedoed the screw…lol. I found the spring but not the screw…lol Now I know how to properly install it 🙂
LOL! @0:50 I have several Aero lowers/parts in my builds. I just 'cleaned up' my gun bench the other day, organizing all my spare parts and such. I literally came across a lone set screw and was like…WTF is this for? I've never used the set screw method for the rear takedown…haha
I have bought many Areo lower and i got to say YOU NEED TO INCLUDE THE SET SCREW WITH THE LOWER LIKE YOU DO WITH THE BOLT HOLD OPEN PIN/SCREW.. IM NOT PLAYING
I haven’t been trimming the spring. I’ve been manhandling that set screw all up in that thing
Installed the set screw without trimming the spring, works