80% Lower + Jig recommendation

[R2BRO]

My build of 6.5G is on the way, I'll re-use my older lower as a starting point.

However, eventually I want to make my own lower, can you please recommend me the best option and best quality Jig or Jig+lower kit?

Also, I have future plans to build AR-10 as well for 6.5Creedmor later. So its better to buy Jig with addition which lets to work on AR-10 platform.

so any great recommendations? (there are so many options, I'm not sure what is it best to get)

[bj139]

I built my first AR from a Polymer 80 kit. With a large drill press and an x-y vise, it was pretty easy.
It makes a nice lightweight lower. I bought several chunks of aluminum which are 80% but have not tried drilling them yet.
I assume 7075 aluminum will be far more difficult to cut than polymer.
I bought the inexpensive jig and aluminum 80% lower from Gunbroker for $100 for both.
I plan to start drilling soon and will post here when I get some results.
With a drill press side cutting should be minimal and down cutting should be used to clear most material.

[Frontier Gear]

I have a lot of experience with 80% lowers. I used to sell them, and I've done a number of them myself. So here is my advise. You can take it or leave it, but I can probably save you some headaches. Also, below is a video that I made detailing how to finish one.

The two best options are either the Polymer80 kit or an aluminum lower with the 5D Tactical jig.

If you just want to try it then I recommend the Polymer80. They come with a one-time-use jig, drill bits, end mill and a threaded bolt catch pin. They are by far the best kit for doing on a drill press. I wouldn't try an aluminum lower on a drill press. It is way too hard on the bearings. Especially if the lower is made from 7075 and not 6061. The drill press just isn't made for that much side load. It can be done, but you have to go slow and it is hard on your machine. Also, most people will screw it up trying it.

If you are serious about making some aluminum lowers, then invest in the right tools. The right tools are either an end mill or the 5D Tactical kit and a router. It will cost some money though. The 5D Tactical kit can also do AR10 lowers with some additional options.

Polymer80 is going to release a new Gen 3 AR15 lower in April. It has even more reinforcements (although I've never broken one of their Gen 2 lowers) and it has an embedded metal strip for engraving a serial number if you so desire or are required to by state laws.

I do have a bunch of new in box Polymer80 AR15 and AR10 80% kits that I've never got around to selling (as kits, not completed). PM me if you want one as I'd like my closet space back.

[Frontier Gear]

Here is the new one that will be out sometime next month or so.

Rhino Kit 1.jpg

[R2BRO]

Hey Frontier Gear, thanks!

In fact, I heard someone on ar15 forum highly recommending 5D tactical kit, and now you just reinforced this opinion.

Since I am not interested in polymer, but aluminum, and since I want to start it and do it right and maybe doing more, I'd go with 5D tactical Kit plus router, in that case I got some questions:

1) The 5D Tactical Kit, what is the lifetime of that jig? Is it still good after many lowers built? Or its going to get bad after one makes say, 20 lowers or so? Is it sturdy enough?

2) Can you roughly recommend which exactly router you think would be better to use with 5D kit? Any link to product will do. Depending on that recommendation I'll have to choose proper size for so called "ReadyMILL"

3) So finalizing, I need:
5D Multiplatform Tactical Kit:

https://www.5dtactical.com/multiplatform-80-lower-jig-p/5d-pmj.htm

The Router Jig Pro Toolkit

https://www.5dtactical.com/80-lower-jig-tool-kit-p/5d-pk300.htm

And there I must select proper size depending on router recommendation.

So is that it? Am I missing anything else from their website to order? Is it all what is necessary to do both AR-15 and AR-10? The only thing I now need is to buy any Al lower from anyone online, correct?

[Mopardoctor]

The 5D router bit is the best router bit. I used a Ryobi variable speed router. Always start at the slow speed, midrange speeds seemed to work the best. I used the Jugernaut Jig. Also, it is way cheaper to just buy a stripped lower.

Mopar Doctor

[golfer]

I also highly recommend the 5d jig. I sit at a desk all day with no machining experience and I have completed 14 lowers. Virtually impossible to mess us a lower. Be sure to tape up the side with drilling your pin holes or the aluminum shavings on the drill bit with scratches the lower as the bit spins.

[bj139]

My drill press has a tilting table with no real lock to keep it level. I can tighten the main bolt but sometimes the bit catches and tilts the table a bit.
I remembered having the same problem when milling the polymer 80 receiver.
I removed most of the aluminum and did not cut too deep. This is a go slow and measure often project just like reloading.
It should take me a few more days to get it done. Safety and trigger and hammer holes look good.
I have to take some pictures.