80% lower completed with Easy Jig

[JAE]

Thanks, the instructions say to take it out so that there is less tolerance needed on a mill that is not as extended.

I'm just going to use a whole new router set up all together to avoid this again

Wow. Your right I just looked at the instruction manual. I did it wrong and used the spacer for ALL milling operations. You know something though.... they came out perfect. I'd do the same again.

Here's a technique I developed for the trigger hole:
1) Don't use a drill at all.
2) With the template and spacer installed, and the router OFF, set the depth of the end mill just so it contacts the bottom of the FCG area.
3) Using the depth adjust screw (my Bosch Colt has a little screw you can use for fine adjust) adjust the end mill into the piece just a little so the base plate lifts. Just a little. maybe a 0.020" or 0.030" cut your going to make here. Remember this is with the router OFF.
4) Put the router and end mill all the way in the back of the template and tilt it a little more so the end mill does not contact the piece.
5) Turn the router on. It should be spinning and not cutting at this point.
6) Gripping the router firmly by the base, slowly ease the mill into the work until the base plate is flush. There will be a little chatter on the end mill. Go slow.
7) Route out what the trigger hole template allows.
8) Turn off the router.
9) Repeat the process until you are through. This will take 4 to 6 times it's actually quite thin there. It will go fast you'll spend more time adjusting and getting it right than actually milling anything.

VIOLA! Perfect trigger hole every time. Don't worry about the end mill walking. The cuts are so small it won't flex much. Give it a try you'll see.

[solislbc]

Sounds scary...I just bought that same colt router, hope it works well for me. I also thought about using a smaller pre drill. 1/4 seems to fit the end mill that I have perfectly. I managed to rig up a diy drill press so the hole I'm pre-drilling is nice and straight. Will using the bit supplied for this hole still cause an issue If I can predrill perfectly straight?

[JAE]

Sounds scary...I just bought that same colt router, hope it works well for me. I also thought about using a smaller pre drill. 1/4 seems to fit the end mill that I have perfectly. I managed to rig up a diy drill press so the hole I'm pre-drilling is nice and straight. Will using the bit supplied for this hole still cause an issue If I can predrill perfectly straight?

If you have a press it's not an issue. As long as the piece is perpendicular in the press your good to go. Issue I had was that by hand it's super easy to get a little off and bugger up the trigger hole. Make a divot out to the side. The little technique I developed is easier than it sounds I can show somebody how in ten seconds and they would get it. No problem. If you can mill the rest of that you can do what I'm talking about. If I can figure it out I'll gate an example picture up of doing it this way.

[JAE]

Attached is a picture of a forged lower I did with the 80% Arms jig and no drill press or mill: hand drill and router only. This using the trigger hole technique I devised as well as a couple of other tricks. It's still not perfect as you can see the partial drill hole at the front of the FCG left over. Working on this I think the jig manufacturers are addressing this as well. Numbers are good (check prints available on this site). As follows:
-FCG width: 0.689"
-Left wall of FCG: 0.094"
-Right wall FCG: 0.100"
-Rear Shelf width: 0.498"

So you see, you can get damn close by hand, have a perfect trigger hole, and do it all by hand with a jig. Just got a to make a couple. I think that was my second forged and my fifth overall.

[solislbc]

That looks good! Looks like you have the same issue I had at the corner nearest the bolt catch. Your pocket is a lot cleaner. I'm going to mill my next one with a Bosch Colt router. Your pocket looks cleaner than mine.

[JAE]

I have a better one but it's in a rifle with a cassette style trigger so pics don't show it well. I was able to get rid of that annoying little divot from the bit as follows:
-Before bolting down drill guide find center. Go side to side in slop of bolts to do this. It's only a little bit but can be easily done. You get a feel for it.
-When drilling with drill guide push it all the way away from magazine for FCG holes and all the way away from buffer for rear shelf holes. So find the center of the slop and jack it all the way away from the ends. Yes?
-When routing with template do reverse: all the way TOWARD magazine for FCG and TOAWARD bufffer for rear shelf.

So you see the little divot is from the slop. I'm sure on the jig makers CAD drawings everything is perfect. In the real world not so much. Use the slop to your advantage for a nicely finished product.

Does any of it matter for a working rifle? Not one bit. It will function just fine and be just as reliable. The only thing to be had here is bragging rights at the range during show and tell. But that's kind of cool so I do it.

[JAE]

Okay so I'm just posting these pics for bragging rights. This is what it should look like.

No drill holes left. Note the sharpie to dull the exposed edges. FCG a little thin at 0.682". Rear shelf spot on at 0.500". Side walls a wee bit unequal at 0.094" and 0.106". I switched the parts to this one after being in a billet lower I made that wasn't as perfect. Other one saw about 200 rounds this one has seen about 100. No problems whatsoever post inspection. The trigger was a little tight going in but it wiggled right down. That's because my FCG is thin but a hand file and a few minutes would cure that. If you make them right everything is a little tight and then dress them out with a jewelers file set for an exact fit. Runs "like a Swiss Watch". No ****.

[solislbc]

Thanks for all the tips!

[solislbc]

Okay so I'm just posting these pics for bragging rights. This is what it should look like.

Wow! Impressive! I hope I can make my next two this clean. I'll also be using a CMC enclosed trigger. What lower did you use? Is that a KEarms lower?

[JAE]

The lower is from Tactical Machining. I believe this is Cerro forge not sure. You can tell by "keyhole" emblem. Got it for $54 with the $29 stripped upper and built it up. Lower parts kit is Ares Armor "Archimedes" this is a great value only thing I don't like is short throw safety they send I prefer standard metal ambi safety. Nonetheless that kit is a great value I wish I could afford more. Excellent for match shooting. Prefer my RRA two stage NM for general use though as it's easy to bump fire the darn thing if you get a little jiggy.

[JAE]

I forgot: that TM forged lower will eat the jig if your going by hand and aren't SUPER careful. Drill press is really preferred for the forged ones they are so much harder it's quite impressive. Nonetheless it can be done as evidenced by the pics just take your time and buy a few extra $5 cheap 3/8" bits. Don't buy the $15 one it won't last 3 times as long.

[solislbc]

i was worried about bump firing with the CM two stage since its rated at 1lb first stage and 3lb second stage. The RR is rated at 3.5 in the second stage so I was hoping that additioanl .5 lbs would not cause issues.

I will probably only have 1 AR in the house for a while and I would hate to have something sensitive in an enviroment where I'm compeled to pull this out as a home defense. Especially with adrenaline running. I'll definitely make sure I run several rounds through my set up before I consider pulling this vs my glock.

[JAE]

Home defense? Meh. Pump action 12ga with birdshot. Or 00 buck your choice. Any gunslinger in the old west was afraid of granny with a blunderbuss. For good reason.