Has anyone here built a 80%-90% M4 lower with a Drillpress? I am thinking about getting a cross slide vise to use in milling w/ my drillpress w/ mill end bits. Can anyone give me some feedback on this idea?
Drill presses are not intended for side loading.
A vertical milling machine is.
I know and plan on drilling all the hole straight down and comeback with the cross slide and take a little off at a time. I wish that I had a Mill in my shop.
I’m interested in this topic as well.
Have you seen one of the many you tube videos on the process?
Looks like it works, although I’m not clear on the quality level of the finished lower.
What he’s saying here is, make lots of holes.
sent from mah gun,using my sights
I’ve seen guys drill away most of the material and then finish the cavity with files.
Not sure what quality this would turn out though.
I’m sure it’d work but it’d look like shit.
I’m still waiting on mine from Feb. This getting to be BS. Not that I’m in a hurry but this has been long enough.
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If you do it right, you can have enough clearance for the trigger, and just leave the slight “wave” left from the holes over lapping.
sent from mah gun,using my sights
MOVED SINCE THIS ISN’T A CUSTOM BUILD TOPIC.
Plunge cuts with an end mill would work to smooth out pocket.
It would take a lot of them, and a file would likely still be needed for the sides on the FCG cavity.
I agree with polymorpheous on this one. Can it be done on a drill press? Maybe, assuming you are ONLY drilling and not milling. You will have to have a really good mill vice, use center drills, stub drills, cutting fluid, etc. You could try to plunge cut with a 4 flute endmill, but anyone that knows the first thing about machining is going to cringe at the idea. The tooling alone would more than cover the cost difference between an 80% and a title 1 receiver.
DO NOT try to side-load a drill press with an endmill. Bad bad things will happen. Especially if you are using some cheesy Dewalt or whatever drill press from Home Depot/Lowes/Harbor Freight.
Personally I wouldn’t try a 80% receiver on anything less than a Bridgeport or similar mill with the proper tools, prints, and a DRO. YMMV.
Some of us metal heads don’t need no stinking DRO!
Sure is nice to have one though.
Damn man, where did you order from?
Ares Armor has a couple of different 80’s in stock.
You’d have it in a few days.
They even got a basic jig for $45.
Lol, as was shown in another thread, you don’t need an optic on your rifle to make hits at 1000 yards. But it sure helps! 
I’ve done my fair share of manual machining using the indicators on the hand wheels, but man, unless it’s a newer (ie less worn) high quality mill the amount of backlash in the hand wheels is so great doing anything where you’re holding .005 in. or less is a damn trick.
I ordered from Ares. The ones I ordered were 7075 that are still shown OOS. I already have access to a jig. I also DWG files that I’ll probably work off of too.
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Ah yes.
I’d want the forging as well.
Ares gets them from Tactical Machining.
Doesn’t help though, because they are also OOS.
Last I checked, they (Ares) were shipping orders from last week in Dec.
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I can help you with billet 80% lowers, but not forged. We are also running AR308 80’s.
A drill press is far less than ideal but I have seen them done with a drill press and dremel. Wasn’t pretty at all, but the rifle is still running lol
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True that. I blew up a carbide end mill trying to clean up the the bedding block for detachable bottom metal on my 300 BLK bolt gun build. My thumb was sliced open - could have been much worse.
I understand the political appeal to “manufacturing” your “own” lower, but from a cost analysis, I don’t see how you would save a penny without doing 10+ lowers due to the tooling cost of doing it right. Obviously folks who have a respectable hobby mill or better at home with the proper tooling are in a different boat, and I can see how it would appeal to them more as a fun machining project with tangible results. But to the guys trying to machine these on a $200 drill press, with little or most likely no machining experience, and a drill index as you only tooling, I think you’re setting yourself up for disaster. I’m not even mentioning the measurement tools you would need to properly inspect your work and ensure you are adhering to the prints. If I were you, I really wouldn’t trust an 80% done on a drill press for much more than a plinker.
Evil thought: Give me a small CNC mill like a Tormach or whatever, a copy of EdgeCAM or Master CAM and I could crank out 3-5 of these a day once I got a good fixture setup.