AR 80% lower finishing - Order of operations?

[Andre]

Nice, before I bought a mill I purchased a set of jigs for AR15 and AR10. They work great, but were $$$. Now that I have the mill I could have saved the money. I am still setting up my new mill, and have not started on a lower yet, but I am getting close.

PICS PICS PICS!

 

[brav65]

Quick shots with my phone. I purchased it here http://www.cncguns.com/tooling.html After I ordered the jig I decided to get a PM25MV with a DRO.

PICS PICS PICS!

 

[ScrapMetal]

Nice work on the jaws! Looks like your set up for mass production of lowers by the looks of things :biggrin:

Do you do any work on 10/22's?

Yeah, I'm planning to experiment with a number of different AR configurations. I know I could have one lower and swap the uppers out but where's the fun in that? I haven't done any work for 10/22s but I've been running different ideas past my son (We bought a 10/22 for him to learn to shoot with.) so it'll definitely be a future project.

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Quick shots with my phone. I purchased it here http://www.cncguns.com/tooling.html After I ordered the jig I decided to get a PM25MV with a DRO.

Much, much nicer setup than the one I had my hands on! Yours was obviously designed by someone with a little foresight and an understanding of what it takes to get the job done. Definitely, if I were to try it with someone's jig setup up, that would be the one I'd get.

I think that you'll find that once you get your mill set up properly with a DRO that those top plates/drilling jig won't be of much use any more. You'll just end up relying on the screen. That in itself has taken some getting used to, for me anyway. I'm used to using "eyeball" and indicators to set things up. Once I installed the DRO I found just how error prone my methods were. It has allowed me to speed up work and have a level of repeatability that I never dreamed of before.

The one thing I may have to do a bit of is to round off some of the corners so as to not mar the nitrided lowers when I'm handling them/putting them in the vise. I'll have more to post when I get to start actually working on the lowers.

-Ron

 

[ScrapMetal]

Got to work in the shop for a couple of hours today. Installed the new jaws on the Kurt and completed the first operation (drilling).



I didn't get a picture with the DTI but it is at this point that I put a test indicator on the lower casting to make sure that the top of it was parallel to the table.





Here is a shot of the completed "first operation". I set the quill stop for the proper depth and then "went to town" on drilling.



Hopefully in the next couple of days I'll be able to get an end mill or two in there and finish milling out the cavity.

-Ron

 

[brav65]

Nice work. Will you drill out more material or just start to mill out the area?

I had to pull the head off my mill to get at a stripped bolt that I discovered when trying to figure out why I could not keep my mill trammed. I am eager to start work on a real project.

 

[ScrapMetal]

Then next step will be to go in with a long 7/16" end mill and plunge/rough out the remaining areas then do a finish cut with a "bull nose" 7/16" end mill. I use the "bull nose" or corner radius end mill to finish up as I really dislike sharp corners in deep pockets. The radius corners are easier to clean and, not that it really matters, are also "stronger".

Thanks,

-Ron

 

[ScrapMetal]

Just a little update. I was able to rough and finish the first of the lowers today. The finish isn't as pretty as I would like but I'll work on that for the next one. Now I have to get it back in the vise and mill the hole for the trigger as well as drill the holes in the sides.





-Ron

 

[brav65]

Nice Work Ron! I got my mill head back on tonight. I will get it trammed in tomorrow night and be back up and running. I just have to mount my X axis scale and set up the DRO and I will be off to the races. This weekend I ma going to a meeting of a local machinist club I am in and one of the member is going to show everyone how to anodize. I can't wait to see the finished product.

 

[Lucky 13]

I am in the middle of my 1st AR build. I started with a 80% forging from Tactical Machining and borrowed the Ares Armor jigs from a buddy that did 2 on my mill. I have the lower complete minus hard anodize. I'm going with a .223 Wylde chambered barrel and have genuine Colt M4 upper.

 

[ScrapMetal]

Nice Work Ron! I got my mill head back on tonight. I will get it trammed in tomorrow night and be back up and running. I just have to mount my X axis scale and set up the DRO and I will be off to the races. This weekend I ma going to a meeting of a local machinist club I am in and one of the member is going to show everyone how to anodize. I can't wait to see the finished product.

I'm going to have to learn how to anodize one of these days. Be sure to let us know what you find out.

I am in the middle of my 1st AR build. I started with a 80% forging from Tactical Machining and borrowed the Ares Armor jigs from a buddy that did 2 on my mill. I have the lower complete minus hard anodize. I'm going with a .223 Wylde chambered barrel and have genuine Colt M4 upper.



Looks great so far. You doing the anodize yourself? Curious as to what steered you towards the .223 Wylde. I've seen a number of references to it but don't know any details.

-Ron