Reducing weight of AR Lower

[Screwball]

For light weight and shorter LOP, check the Ace line of stocks...ultra strong and truly light.

Yep... that's what I did. Went with the Ultra Lite Entry stock, and it is like nothing is there.

 

[Arizona_Mike]

I managed 4.32lb, 5.22lb with an optic, 3 pt. sling and a few other accessories. Some very pricey parts, but It was a fun challenge and I ended up making a rifle I love to hike with.

http://www.thehighroad.org/showthread.php?t=766900&highlight=ultralight

Mike

PS. Since I've built this, V7 has come out with even more titanium parts that did not exist when I made my build. I see at several I could have used without breaking my "rules" in my initial thread. I wonder if that titanium barrel nut and clamps for the KMR rail would have gotten me to my initial goal of 4.25lb.

 

[MachIVshooter]

I managed 4.32lb, 5.22lb with an optic, 3 pt. sling and a few other accessories. Some very pricey parts, but It was a fun challenge and I ended up making a rifle I love to hike with.

Those monolithic lowers are certainly the lightest option! I find them kinda ugly, though.

My featherweight had two objectives: under 5 lbs, under $500. I would have made the $500 mark without the flip up sights and Hogue Grip:





That is with flip up sights and the Trijicon MS04 on my custom mount. Of course, there was a lot of machining, both in lightening existing parts, and in making my own. So, no, that budget isn't realistic if you don't have a mill and lathe at your disposal.









The basic parts list is:

Aero LW upper, lightened
Ares Polymer 80% lower
Standard LPK
DSA BCG, lightened
Standard charging handle
JSE M4 barrel, turned down to 0.540"
Aluminum gas block
Cheap 10" aluminum FF hanguard, lightened
Cheap polymer flip-up sights
Blackhawk stock on standard M4 extension, carbine buffer

hand made parts:

7075-T6 MS-04 mount
7076-T6 selector
6061-T651 receiver extension nut
6Al-4V muzzle brake

 

[BSA1]

magnesium alloy lower

I can't seem to find much recent information on magnesium alloy lowers. One old complaint is the finish wears and chips off easily. There are also comments that the lower can not be refinished.

 

[MachIVshooter]

I can't seem to find much recent information on magnesium alloy lowers. One old complaint is the finish wears and chips off easily. There are also comments that the lower can not be refinished.

I don't have enough experience with them to comment on the finish wear, but the notion that you can't refinish is pretty absurd. Anything can be Cerakoted, save for certain highly chemical resistant plastics like UHMWPE (basically nothing will adhere well to that stuff, including epoxies!).

 

[IndianaBoy]

If you are looking to save weight and you are considering paying someone to mill cuts into your lower, might I suggest you put that money towards a tax stamp and go with a SBR.


There is precious little weight to be saved in a lower receiver but an 11.5 pencil barrel will be much much lighter than a standard 16 inch barrel.