80% Lower Recommendations?

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Planning to start an 80% lower AR build. Soooo many options out there. I have both a router and drill press. I've done a full saiga AK conversion in the past, and have decent basic skills at the workbench, but this will be my first AR build.

Any recommendations? I almost bought a jig and lower from polymer80.com, but have been reading a lot of horror stories about their stuff just not lining up right. I don't mind spending a few bucks on a jig, or even some new equipment (within reason), but would love to hear a success story and know which manufacturer you bought from.

Thanks!
 
I used the modulous arms jig and it has been great. Works great with a router (variable speed) and a press. I highly recommend the jig. That said I haven't tried any others.
 
I used old style modulus jig on two. Both came out fine. New jig looks even better. Used drill press for holes and small DeWalt router for opening fire control pocket. I tried Bosch router but depth adjustment sucked and chuck not square to motor so returned it. You Definitely want a router that has easy and repeatable depth adjustment as you will use it a lot! Used small machinist vise to hold lower (in jig) for drilling and routing.
 
I would avoid polymer and go with aluminum if you want it to be a serious rifle that will last a while. I like Tactical Machining lowers, they are even better when they go on sale for $29, but stock is pretty thin everywhere right now:

http://www.tacticalmachining.com/80-products.html

That Modulus jig looks awesome. I've used a really cheap jig from TR Enabling and a benchtop drill press. It's a hack way to go, and the inside of the receivers looks like they were gnawed out by a beaver, but it does work. I have had to replace the top plate every couple of receivers because I suck at machining.

http://www.tr-enabling.com/category-s/1891.htm

Given the state of the market, I would just buy any aluminum 80% that I could get. Tactical Machining has at least something in stock. And if you want a really nice finished product, use the Modulus Arms jig.

Good luck
 
First go aluminum. If you only have a router then go with the modulus jig. Machining on a drill press is way to much work and difficult to get a very good quality finish. Never mind not safe. I have seen the chuck come off many times doing polymer. I can't imagine it on an aluminum. Your pin position and their hole size is the most critical. Go undersize on the trigger pins. The rest is just a big hole.
 
not sure if serious.

there are other options like casting one in plastic, also spotpeople are selling ar lower that you can weld up from the pieces of steel that you can buy from them.

route, pour, weld ... probably not exhaustive list of making your 80% 100%
 
Last weekend I did 2 lowers on the modulus heavy duty jig. Worked great. Cheap drill press and small Bosch router. First time I ever routed anything. The jig still looks great. The router template wasn't consumed.
 
there are other options like casting one in plastic, also spotpeople are selling ar lower that you can weld up from the pieces of steel that you can buy from them.

route, pour, weld ... probably not exhaustive list of making your 80% 100%

The flat spot also sells ar15 and ar10 lowers you weld up.
 
Three more tips.

I did ruin one top plate on Modulus jig, it appeared friction between the side of the router bit (end mill bit) and the top plate sintered (powdered) the edge of the top plate. (this was the all aluminum jig) After replacing the top plate I used some cutting oil as lubricant between edge of bit top plate, and since then no issues. the old top plate is still used to hold guide for drilling the holes in fire control pocket.

Because of this I would recommend spending the extra $ to get the new design Modulus jig which appears to have a steel (?) insert for edge guides.

I also bought the Modulus tool kit with end mill bit and proper size drill bits. Just keep it together with the jig.

I could not find cutting oil initially, and used 3 in 1 oil at first. I accidentally found cutting oil, which works better, for sale in the plumbing department of Lowes or Home Depot. It is used for cutting pipe threads. (People in tool department did not even know what cutting oil was)
 
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