Lower Build Tips/Lessons Learned

[Fixxah]

Tap out the rear detent spring hole and use an allen screw to lock it in. It makes grip changes easier.

 

[Romokid]

it pains even to read all that struggle - aero m4e1, again, and forget the pain. life can be way easier.

My son just bought one on Sunday and they definitely make it way easier with the bolt catch screw, integral trigger guard and the rear take down pin detent channel is already threaded for a 4-40 set screw. I may have to look at adding one.

 

[pastera]

It’s not about using the right size punch or even keeping the catch in place with a slave pin. The problem is the shape of the lower and not being able to keep the punch straight.

Like it or not, using pliers and taping off the lower or pliers is a safe, repeatable, and easy method to install the roll pin.

- Get it started with the punch

- Push it most of the way in with pliers

- Finish it up with the punch

I made a punch on the lathe from 3/16" round stock
Center drilled a dimple (~0.03" deep) in the end offset from the center toward the edge
Spun the rod 180° in the chuck and drilled a #40 (0.098") hole in one end about 0.25" deep (same offset)

This lets me get a good start on the roll pin by holding it in the punch to start then using the dimple to get it pretty much home.
Just turn the punch around to tap the pin flush.

The commercial punches that are ground flat are nice being hardened but they don't help with getting the pin started

 

[paul73]

My son just bought one on Sunday and they definitely make it way easier with the bolt catch screw, integral trigger guard and the rear take down pin detent channel is already threaded for a 4-40 set screw. I may have to look at adding one.

you may also like how the aero m4e1 upper marries with the aero bolt - very snug and runs nice. it is just easier when all those parts are made to a same spec and there are no gotchas. aero is not a top tier stuff, but it is as least machined correctly and all dimensions are what they are supposed to be.

 

[Romokid]

you may also like how the aero m4e1 upper marries with the aero bolt - very snug and runs nice. it is just easier when all those parts are made to a same spec and there are no gotchas. aero is not a top tier stuff, but it is as least machined correctly and all dimensions are what they are supposed to be.

He was able to grab a Spikes Tactical M4 16" complete upper last year for just under $600. I have a spare stocks, brakes and LPK's so all he needed was the stripped lower and a rear sight, but it good to know that Aero should be good to go.

 

[Romokid]

Tap out the rear detent spring hole and use an allen screw to lock it in. It makes grip changes easier.

@Fixxah, In re-reading do you mean the safety selector detent hole above the grip? or did you mean rear detent spring for the take down pin with stock changes, that is the one that Aero sells already tapped for a 4-40 set screw. If you did do the safety selector detent what size? Does the 4-40 size work for that as well? as I am now considering the grip one as I have some Magpul Moe grips to install.

 

[Fixxah]

@Fixxah, In re-reading do you mean the safety selector detent hole above the grip? or did you mean rear detent spring for the take down pin with stock changes, that is the one that Aero sells already tapped for a 4-40 set screw. If you did do the safety selector detent what size? Does the 4-40 size work for that as well? as I am now considering the grip one as I have some Magpul Moe grips to install.

Above the grip. Makes grip changes easy and you will never lose the parts. I have only seen it and wish I had done it on all of my rifles

 

[paul73]

Tap out the rear detent spring hole and use an allen screw to lock it in. It makes grip changes easier.

Aero lowers come like that from factory. You only need to cut about a centimeter off the spring not to make it too stiff to move.

 

[Romokid]

Aero lowers come like that from factory. You only need to cut about a centimeter off the spring not to make it too stiff to move.

@paul73 he is talking about the safety detent not the rear take down one. I like the idea of the safety one to swap out grips but I’m not sure what size tap and set screw to used as I think it is slightly larger than the take down detent hole.

 

[paul73]

@paul73 he is talking about the safety detent not the rear take down one. I like the idea of the safety one to swap out grips but I’m not sure what size tap and set screw to used as I think it is slightly larger than the take down detent hole.

Hmm. There is only 5-6mm there only - how would that work? But, may be, ok.

 

[Amputee Marksman]

AR-15 PIVOT PIN DETENT INSTALLATION TOOL | Brownells

Makes installation of the M16 pivot pin and its detent faster and easier. Prevents loss of detents. Guides detent and spring into place and serves as a slave pin when installing the pivot pin. SPECS: Blued steel. ј' (6.3mm) diameter. 2Ѕ' (6.3cm) a...

www.brownells.com

Save yourself some money. A $2 Clevis pin from the hardware store will do the job.

 

[IPSC_DRL]

Lesson learned;

Don't start assembling a lower and then "put it aside" for several months and forget about it.


Danm, where did I put that lower?????