Part 1 - Open the port:

Here's the barrel.  AR Stoner 16" SS .50 Beowulf Barrel, with matching bolt (I'm assuming they headspaced using the provided bolt.).  Another member mentioned on another thread that he called AR Stoner and found out that their barrels are made either by ER Shaw or Wilson.  My guess is that this is a Wilson barrel.













I also ordered an oversized dust cover to use in place of the standard cover.  Here is a photo comparing the two.  The oversized dustcover is 0.040" taller.



I chose a Vltor upper for this build as the beefy nature seemed to lend itself to this application.  Also, they just look cool and Vltor is a local business.  

I needed a way to hold the upper at the proper angle on the mill table in order to machine the ejection port properly.  I decided to make a mandrel/fixture that would wrench onto the receiver as if it were a barrel, using a standard steel barrel nut.  

I ordered some of these really handy blank arbors a couple of years back and they are worth their weight in gold.  These have a hardened taper section and a blank portion ahead of the taper which is left soft and machinable.  These particular blanks have an MT2 taper, the same taper that fits inside my rotary table.



Machining the mandrel.  Copied the dimensions of a real barrel exactly, only the mandrel needed to be slightly shorter to prevent the endmill from touching it while machining the port.  Say 0.025" shorter, just enough for clearance.





I then drilled a hole all the way through the mandrel and added a 1/8" spring pin, to take the place of the indexing pin on the barrel.  This probably was unnecessary, but I figured it would rule out any possibility of the receiver rotating on the mandrel.







Now that I had my mandrel, I needed some way to support the opposite end of the receiver while doing the machining.  I created a nylon plug that fits inside the internal bore of the receiver on one end and fits the dead center of my mill table tail stock on the other.





All meta machine work is now complete.  Time to wrench the mandrel to the receiver and set up the mill.



I used dial indicators to ensure the receiver was properly oriented in all three axies.



Here is the ejection port, before any modification...



First I trimmed back the landing for the dust cover by 0.040" as the new dustcover is exactly that much longer than a standard dustcover.  I used a 1/2" endmill for this operation as it matches the 1/4" radius on the dust cover.



Next step was to open the port towards the top of the receiver.  I used a 3/8" endmill to create a 3/16" radius, in order to square up the corners of the port a bit.  This is to to help stop the cartridges from binding on the original large 1/4" radius.  I opened the port to the north by 0.035" leaving 0.005 in case I made a mistake, I'd have 5 thou to fudge with.



Next, open the bottom of the port by 0.105", same 3/8 endmill.



Port is now fully opened.



Now, if we want the dust cover to function properly, we need to re-cut the detent cams (I don't know the official jargon, but you understand what i mean)  The outer one is easy, a ball endmill makes short work of this task.





Ok, this is the tricky part.  How the heck do you cut the inner cam/pocket?  Obviously, from the original shape of this cam surface, there is a specialized tool for this operation.  I do not have such a tool.  I decided to fudge it by eye with the same ball endmill, since all we really need is a place for the detent to rest when the dustcover is in the closed position, and provide a way to compress the detent spring so the dustcover can open when pushed by the bolt carrier.  I changed the angle of attack and did this by eye.





That's the end of the mill work on the Upper.  De-burr and test oversized dust cover.  It works!  That's a relief!





Link to video of new dustcover operation



Part 2 - Upper Assembly:

Well, I've got all the parts I need now, excluding the muzzle break and some ammo (which appears to be in extremely short supply right now).


Here's the Gas Block, a LaRue .875" ID 0.300" spacing, low profile gas block.



And the handguard, a LaRue 11" (This thing as a little heavier than I had hoped.  Not that a little extra weight is a horrible thing on a heavily recoiling gun.  Still, I'd like to keep this rifle reasonably lightweight.  This thing is very SOLID however, so that balances out the weight disadvantage.  Also, the built in QD sockets are a huge advantage.)



Insert barrel, slather threads with moly goo.



Torque the barrel nut.



Assemble gas tube to gas block and check for proper fit.

I had a heck of a time driving the gas tube roll pin into the gas block.  I used the spring pin provided by LaRue in the gas block packaging.  Eventually, I got it in there, but it was a PITA with the bench block I have.  Also, just FYI, as far as I know, all Beowulf uppers use a Mid-Length gas system.  Therefore, what you see here is a Mid-Length gas tube.



Install handguard.  This is a little tricky and it took me a moment to figure it out.  You have to put the handgaurd onto the barrel, but don't thread it on.  Then, insert the gas block with gas tube attached.  Now that the gas block is in place, scoot the handguard back and forth until one of the little holes on the bottom of the handguard lines up with one of the set screw holes in the gas block.  Insert set screw, repeat for other hole.  Then and only then tighten and secure the handguard.  Once again, I can't stress enough how solidly this thing mounts.  It's a rock.



M4 feedramps should in no way interfere with the feeding of Beowulf carts.



Here's where the Mid-Length gas block ends up under the 11" handguard.  Looks like I could have gotten away with the 10", but this way the gas block is completely shrouded from bashing, and I do get a bit more sight radius.



Well, here she is.  Technically, she is ready to shoot.  I could slap some sights on her and take her out today, assuming I had even one round of ammunition.

awesome work! can't wait to see more.

/Darth Vader voice: "Impressive. Most Impressive"

Nice work! I'll be watching this one!

Brad

Very cool I have to tag this one...

I want a mill

nice work, can't wait for the next installment

OST

I found mine on Craig's list a few years back.  It wasn't expensive used, couple hondo.  It's all the tooling that adds up to be expensive.

It's tiny and it has many limitations, but I've been able to do quite a bit with it.  You have to get really creative sometimes.

Sorry, not up on all the ARFCOM jargon.  What is OST?

Edit: Looked it up.  "Old School Tag".

Nice work. Tagged for sure.

Hot Damn!

+1k Very Nice!  What kind of mill are you using?  X2?

It's this thing...


Similar to what they sell at harbor freight these days, but this one was made in Taiwan, not china.  Stamped 1998.

I just wished i had your tools and the time to use them

Understood.  It took me many years to assemble the tools that I do have, and I fully appreciate what I have.  I try to use them as much as I can, as I know there are a lot of guys out there with more talent, that would love to have a tiny machine shop in their garage.

I have no children, so I probably have more time for projects than the average hobbyist.

Wow...I'm lucky I can butter toast  

Awesome work!

Wow, and here I thought you were just going to put some parts together.  Nice work so far!



Are you going to leave the port bare or get the upper reanodized?  

Neither, planning on duracoating or similar after everything is said and done and I know it all works.  Going to leave it bare until then.

Well, I didn't have to cut my own chamber, make my own barrel extension, or calculate the size and position of the gas hole.  That barrel/bolt pair really made this project realistic, for me anyway.  Not that I couldn't do all that, but I probably wouldn't have taken on such a big project with the amount of experience I have.  Once this project is complete and successful, I might have the confidence to go all the way.

EDIT: Assuming all that is even possible with my tiny machines.  It is very difficult working with any workpiece that is longer than a few inches and/or larger than 3/4" in dia.  You have to get really creative, or choose your projects wisely.

Wish you were my neighbor
458

Part 2 added to original post.  Enjoy.

Had lunch with LLCoolBeans today and he was explaining this.50 build and I still had no idea he could do all this metal work! Very cool to see it explained with photos!

Can't wait to see it go BANG in person!

~AzRover
GunBurger.com

Damn. Nice update.

Your doing some great work Can't wait to see the end completed result. Cheers to your talent.

Awesome work here.

Awsome. This is the kind of stuff we need in the build it yourself forum. Are you gonna re-anodize it now?

No, as stated before, I'm going to make sure it works, before committing to a new finish.  Also, I'm more likely to refinish with duracoat or similar epoxy paint finish.  I'm open to suggestions.

that is freaking awesome

could you mill out an a2 upper with your set up ?

i've been wanting to build a kiss 8" wulf on an a2 upper

i could pay with ammo

great job and look forward to hearing how she shoots.

I don't see why not.  Not sure I want to start working on other people's guns, due to liability reasons.  Plus, anything I do is SLOW.  Time = $.  You'd probably be better off, contacting a professional machinist.

Let's wait and see if it actually works, first.  Then I'll think about doing it to another receiver.

If you are willing to trade Ammo for mill work, does that mean you are willing to trade for $?  PM me if you are.

Just got a shipping confirmation for my SS bar stock.  No word from Alexander Arms.

Looks like I may be making my own muzzle break.

Sorry. Missed the anodize post. Take lots of pics if you do the muzzle break. I wish I had time and cool toys to play with.

No harm done.  I'm not going to pretend like I read every single post on every thread I'm interested in.




Okay.

I can't believe I'm the first guy out there to try this.  AR Stoner is selling the barrels.  Somebody must be using them for something.  I guess guys just use them as replacements on their Alexander Arms uppers?  That's boring.

Anyway, I desperately need some ammo, or better yet, brass.  If anyone knows where I can procure some, please PM me ASAP.

Looks like this place has some stuff in stock. Never dealt with them before though:

http://www.impactguns.com/cgi-bin/sc/productsearch.cgi?storeid=*1abc1b5b710f748612d07f86085ac6

It all says "out of stock - accepting orders".  I appreciate the effort J.

Wait, I meant to edit the above post, but must have hit the quote button by mistake.  Oops.

ammoman.com has 50 BMG in stock.  I've used them before, no complaints.

.50 Beowulf, not BMG.  Two completely different animals.  Again, I appreciate the effort.

Friday vanity bump...

With bonus photo!  

Wow talk about stopping power.

Whoooa wait, those are solid brass bullets? Thats fricken insane! You could go dump truck hunting with that!



 

Ya.  

You wanna' come along?  I'm just waiting on my tag.

I also put in for Hummer and brick wall.

Thor's Hammer solid brass 50 cal Beowolf = CEMENT TRUCK KILLER!!!  

Very impressive mod indeed!!!

I'll buy that ticket to ride!!!

Vanity bump.

Bonus photo...  What is that beaner up to now?

My god those bullets look serious.

Friday vanity bump...  Busy this week with protests, but I plan to get at least some work on this project done this weekend.

Bonus photo...  Just need to cut away everything that is not a muzzle break.

Hey, 1776 views!  I like that number!

USA USA USA USA USA!

OK I give up what is it? I thought some kinda die or maybe an knurling tool?

You want a hint...

http://www.gggaz.com/index.php?id=64&parents=38,40

Sight wheel for a BUIS.  You gonna make your own?



 

You got it.  Calibrated for the .50 Beowulf trajectory at four different distances.  Also, it's an overall improved design over the stock GGG wheel.

Work in progress.  Got the math figured out, just need to draw up a sketch and make it.

Friday vanity bump!  With bonus image...

Still working out the details, but here's the basic idea.  I'm using the King's Armory break as a guide, since that is what I wanted in the first place.