Just placed an order for the parts I don't have or am not going to make.  Standing in stark contrast to the billet steel lower I just machined, this one will be built on an Ares polymer.  On the way is:

Anderson stripped upper, $50, will be milling a slot straight through the center of the pic rail, milling off the FA tunnel and plugging the hole, not running a dust cover.  (I'm not going slick side because I do   want the case deflector.)
14.5" M4 chromoly barrel, $95, gonna turn it down to .550"
standard gas tube, $10
JSE shipping: $10

aluminum gas block, $8
no name 10" keymod FF hand guard, $60 (claims 10.4 oz w/nut, we shall see how it is......)

PSA Blackhawk LBK W/O FCG, $84 shipped

Already have:

Ares polymer lower, it was $50 on sale
Hammer, gonna shave it down some

Will be carving on a DSA BCG I already have, which would count as $79 shipped.  No charging handle; this is gonna be a side charger with a 7075-T6 knob

I will be manufacturing:

hybrid 7075-T6 aluminum/ D2 tool steel trigger
7075-T6 selector
7075-T6 magazine catch & button
6061-T6511 castle nut
7075-T6 take down pins
6Al-4V ELI comp

Will not be running a rear plate at all, material will be removed from the Blackhawk stock.

No iron sights, just going to go with a Burris Fastfire III.

At a later date, I may make a carbon fiber hand guard for it, but I really hate working with that stuff (nasty dust, nastier splinters) and, to be honest, I was really curious about this inexpensive hand guard, which looks good in the pics and claims pretty light weight.  If anyone is curious, it is this one.  If I end up liking the build, I'll most likely switch to an MI SSK10.5 or BCM KMR 10.

As for the barrel, yeah..........I'm still experimenting with turning down barrels, so it'll only be small tears if I fuck up a $95 tube.  Had good luck on the one M4 barrel I did, but I also only went to .600".

Anyway, my out of pocket (before the RDS) will be $446, as I already have all the materials on hand for the parts I intend to make.

We shall see how it turns out!

You've got way too many interesting builds going on right now.  Can't wait to watch this one.  FYI, the Anderson sport upper receiver has a case deflector.

This is the upper you are looking for.

Exactly. Sure is a lot easier.. Thats what I used on my most recent LW build(all mine are LW builds tho). Saves approx 2oz total having no FA or dust cover.  Barrel is a DD 16" 1x7 .625 pencil barrel(carbine). Its just under 6lbs with irons.

Interested in seeing how you do the hybrid trigger.  Are you worried about the takedown pins galling from the detents?

I used this polymer upper for my lightweight build. It's just a hair over 5 pounds loaded with a Lancer 10-round mag.

I also used the New Frontier Armory polymer lower with polymer FCG for additional weight savings. I replaced the stock with an Ace ultralight though.

Thanks for pointing me to that upper, guys.  I was unaware that Anderson had such an offering.



The sear engagement surface will be D2, with thin ears that come back to the pin.  It will be nearly hollow, and the aluminum piece will fit into it.  Probably kinda tough to envision, but it'll make sense when you see it.



Take down pins, no.  Selector, yes.  I intend to round the selector detent a little, and will probably clip a couple of coils off the spring.

Maybe a titanium selector?

If I had a piece large enough, yes.  But the only Ti stock I have is 3/4" round; would need 1-1/8 or larger for selector, and that shit is expensive. I have gobs of 7075, 2219 and 6061 hanging around. Also, Ti is about 60% heavier than aluminum.

I'm going Ti on the comp because I already have the stock, it has a much higher melting point than Al (flame erosion a real concern on a rifle muzzle device), and I like the way it looks in natural finish.  I am not going to coat the one I made for the wife's rifle:



Also going to be ceracoating the aluminum bits, and the surface hardness of that stuff is pretty incredible.  I don't think wear will be an issue.  The Take down pins will remain natural, but the number of times they'd have to be manipulated for a brass pin to cause any significant wear is a lot more than the number of times I foresee removing them.  If it does become an issue, smaller pieces of Ti round stock as would be required for the pins is not that bad cost wise.

I hacked a lot of weight off a 16 CMV midlength barrel.  I'll Mic it later, but everything past the gas block is close to if not under .500. I only have about 1000-1500 rounds on it, buts all been with a Bumpfire stock.  I still ha ent gotten around to making a LW comp/fh for it tho.  Too many projects.

First piece of the puzzle is done; the LW selector.  On my scale, a standard selector curbs at 17 grams:

Too bad titanium is so expensive. You could do a semi hollow selector and probably come close on the weight. Wish I could "borrow" some from work from our entire skid of 4"x4" rounds from a job we don't do any more.

Turning barrels can be a pain. I assume you have a follower and a steady rest? Having both is helpful. Also, Green Mountain has chambered barrel blanks with extension for I believe a little cheaper than the barrel you were.looking at.

I've done it, but no, no follower or rest (or tail stock).  The Hardinge HCT is not set up for either, and has very little clearance over the massive carriage with it's 8 position turret tool holder, so I end up profiling them about 3" at a time.

Though not pictured, I do use a 9" Buck 3 jaw for most work, sometimes my 5" independent 4 jaw hardinge.  The collets can be handy, but the chuck is more versatile, and it's mass (about 70 pounds) adds quite a bit of rigidity/damping.

No tailstock just seems a little crazy to me.  You might be able to make a custom follower that mounts in the turret with the toolholder.  

I have a ~60 lb hunk of 2219 that is going to become a tail stock, just haven't got around to it yet.  Can't really use anything available due the the size of the carriage.



Would move with the turret.   If you keep the amount of stock hanging out short, you don't need a follower.  The bore through the arbor on this lathe is 1.3", so I can fit any normal gun barrel through it.

It's a unique lathe, US made and very high quality, but a bit more specialized than your typical models.  It's not what I would have gone for if I'd been shopping with cash, but I traded a Mini-14 for it, so........

The Hardinge chucker lathes are very, very precise, and the 8 position turrets allow one to reproduce small parts very quickly and accurately.  IIRC, "HCT" stands for "Hardinge Chucker, Toolroom"

I don't have many attachments for mine, but here is a video of a fellow who does, and really knows how to run the machine:

https://www.youtube.com/watch?v=w-cgJb6j9ak

Beware some of those Keymod handguards dont have a recessed portion in the metal on the forward portion of the key hole to allow for some attachments to fit properly. i could not attach Noveske handguard covers to mine because of that issue.

It is a pretty interesting lathe. I like that it has that much room through the chuck, that's a rarity. I've got a mid 1950's 10" Cincinnati with a 36" bed with the "high speed" option, which equates to a whole 1600 RPM. 3 and 4 jaws, center, 5c collet system.  Also a 16" lodge and shipley from the early 40's that's just a beast. It has a 3 and 4 jaw, but the 4 jaw is all that's ever on it because its too damn heavy to change.

Eh, that's fine.  Not planning to attach anything anyway.  Honestly, I think keymod is fucking retarded, offers no advantage over threaded holes.  You still need a wrench to put rail sections or accessries on it. But it's all the rage now, so that's what we get.



Yeah, I had a choice between the HCT and a Monarch just like this one:



It came with a 16" 4 jaw.  Problem is, one needs a shop crane to change chucks or install/remove tailstock on that monster. The machine itself weighs nearly 4 tons with tail stock.  That's why these huge manual lathes have shit for market value; nice as they are, they're too large and heavy for the hobbyist, and too dated for most industrial uses.

Well, I abandoned the side charging idea, as I deduced that the weight savings, if any at all, would not be worth the trouble.  Instead, I decided to lighten the Aero Precision LW upper I got.

Starting weight was 189 grams, it is now 170 grams:

Still have to do my hybrid trigger, and re-do the RE nut, since the threads went crooked on me, but it's basically done otherwise.  Rest of the parts showed up yesterday, so I was able to get cranking.  Turned the barrel down to .540" both fore and aft of the gas block, made several cuts to the bolt carrier, and machined the 3 port brake, which is now pinned.  Still need to ceracoat the upper, but I want to make sure everything runs right before I do that.







Took a different approach to the pinning, as I did not want the Ti to discolor from welding.  Instead, I drilled and tapped the comp #10-32 at the 6 O'clock position, installed it, marked the barrel, removed the comp, spot drilled the barrel .100" with a 3/16" end mill, reinstalled the comp, slobbered the stainless 10-32 socket head with red Lociite, ran the screw in until the head stripped, then cut it off and ground it smooth.  You can still tell, but no discoloration, and obviously the SS screw stub isn't gonna rust on me.



I'm sure there are those who will poo-poo the idea, believing that only pin & weld or silver solder are acceptable.  To those folks, I will remind that the criteria for "permanent" is that damage must occur to the muzzle device, barrel or receiver before the device comes loose by trying to simply unscrew it.  This method is just as solid as P&W (probably moreso than many P&W jobs), and would still require drilling or cutting to remove the comp.

Well, I got to run it a little this afternoon.  Not a single malfunction, softer than expected recoil impulse, and the cheap barrel that I cut down was giving me 1-1/4" to 1-1/2" 5-shot groups at 50 yards using PMC 55 gr and the cheap flip-up sights.  It maintained those groups even when quite warm, and does not string.  I'm gonna have to give a thumbs-up on teh $95 JSE 1:9 M4 barrel!

I did try it with an empty buffer, and while the rifle ran 100%, the recoil impulse was noticeably sharper.  I don't think I wanna hammer a poly lower any more than necessary, so I'll live with the extra 2 ounces of the carbine buffer.

If you have an adjustable gas block, just turn the gas down and that problem will go away. I built a polymer ultralight with a light BCG and a buffer with the weights removed. With the gas turned down, it's still a soft shooter even though total weight is about 4.7lb empty with optic (Burris Fastfire II) installed.

I don't.  The objective of this build was under 5 lbs, under $500.  I may drill & tap the block and install a needle screw to regulate gas, but I wanted to see how it ran and what sort of accuracy I'd realize before throwing any additional time or money at it.  Since it did work out so well, I can justify doing a BCM KMR or MI handguard to drop another ~4 ounces.

Redbarnarmory has an adjustable gas block for $20.

How is the handguard and where did you buy it?

Thanks!

Enjoy reading your post.  I am doing something similar right now.  I would suggest no AL gas block they do not hold up well, I've taken them off after a single 200-250 rd range session and the port was eroded.  I think the the light running gear you need to turn down the gas.  I would use the adjustable gas key and the Faxon type light steel gas block, or buy one of the cheap ones and lighten it.

Thanks for thinking of us.

Great looking build!

Pretty decent for a cheapie.  It's not a permanent part of this build, but was necessary to stay under the $500 mark for the initial build.  On the budget side, I definitely like the UTG Pro super slims better, but they're still almost twice what this one was.  It's definitely one of the better hand guards I've come across in the $60 range.

I got in on fleabay:

Linky



We'll see how she rides.  For $8, I don't really care if it gets thrashed.  If it does, I'll build a new one out of 6/4 Ti.  As for reducing gas, it's not necessary if I stay with a standard carbine buffer, despite the lightening of the carrier.  But yes, to run an empty buffer, it needs to be lessened.  Not a big deal, though, as I made it under the 5 lb mark even with the standard buffer, and a couple of ounces on the back end is barely noticed at all.

Thanks.  I want a keymod as well, so the price difference is even larger.  I have more expensive rails, but I dont really want one for this build.  I was considering NcStar as well.  Any opinions?

I have the same handguards in 7, 10, 12, and 15".  They are sturdy.  I have some like what you posted, and the newer version that uses a thinner nut are .4oz lighter.  I am waiting for Faxon to release their 11.5" pencil (and/or get the 16" pencil back in stock) to precede with mine.  

However on the handguards I started lightning one of mine and got 2oz of the 7" version so far.  What I did was mill out a .36" hole on every other slot on the top.  I made several other holes and starting milling out the block under the nut.

Very interesting build.

Only two thoughts:
1) Use a steel gas block; and
2) Install a lightweight front sight (ex. Magpul) just in case the battery in the Burris Fastfire III runs out. The window is small enough
on the FastFire that if you line-up the front sight in the middle of the glass you will be close enough of a short-range shot.
This is what I do with my FastFire II set-ups and other RDS’s.

What size ball EM did you use to flute the upper? About how deep are they?  I don't mind leaning as I go.  I'm looking to lighten a build for my dad who destroyed both rotator cuffs.  I also scored a couple pieces of 1" round stock to attempt a TI flash hider.

Where can I go to school to learn how to do things like this?  Simply amazing.

1/4".  I didn't really pay much attention to depth other than to say a little less than half the thickness of the wall.

It looks kinda cool, but weight savings is insignificant.  Only about 6 grams total for both sides.  The 3/8" cut along the top was worth a lot more (10 grams), but still, the total weight shaved off the upper was only 19 grams (2/3 oz).  I cut 4 times that off the bolt carrier.  Heck, the aluminum selector saved more weight than the side cuts on the upper.



Ti is kinda fun to work with, but remember that it is extremely elastic.  Use cobalt or carbide drills for boring, and keep them cool.  Ti has low thermal conductivity, so virtually all of the heat is imparted on teh cutting tool.  I actually got boring bars hot enough to soften the braze, and the carbide tip came off.  If you don't have coolant flooding, just be sure to back the twist drill out very frequently and cool it.  I have flooding, but it's messy, so I put a bowl underneath the thing and simply cool it with water, until I get deep enough that it's really starting to grab, at which point I use GL5 gear oil along the entire bit and let it air cool between plunges.   I have also found that regular old HSS taps work fine, but don't go for more than 75% thread (for 1/2-28, make the minor diameter 0.470"-0.475"), and use high pressure cutting lubricants on the tap.  Spiral flute taps work a lot better than straight flute, too.

All good info.  You confirmed what I thought I knew about all of it.  Added a bit too

Thanks and keep it coming!

Wassup Sixty! Good job on the machining and custom parts, very nice sir.

Now get to work and make that titanium gas block!

One thing to add to Sixtysixdeuce's post.  If you start making a decent little pile of chips cutting the titanium make sure you don't have anything get hot enough to light it on fire.  It's an impressive show, just not when it's in your machine bed... Your home fire extinguisher isn't going to put it out either.

66D,  now that you've had some time with it, what is your opinion of the polymer lower?  I've been wanting to do one, for no other reason than to form my own opinion.  Just haven't decided if that is good enough reason.  Too many other projects in the hopper.

It works just fine, but there's no good reason to go that route unless you're trying to shave weight.  There is some flex in the RE housing.  As such, I don't think poly lowers are a particularly good choice for pistol builds, since the RE is just hanging out there in space, absorbing all the energy of the buffer and BCG slamming against the tube without the support of a shoulder behind a stock.  Maybe it would never be a problem, but with the amount of flex I see putting the receiver on my knee and pressing down on barrel and buttstock, I'm of the opinion it would be a poor choice.

I'll be able to more thoroughly evaluate it down the road, as I only have about 400 rounds through this build so far.  I will say that I've been impressed with the accuracy of the $95 JSE barrel that I modified so heavily.  I did not expect this thing to perform so well, but I'm able to average 2.7 MOA 10-shot 100 yard groups with ball ammo and the 4 MOA Trijicon MS04 from a rest.  I'm betting it would be 1.5 MOA or better with quality ammo and a scope.

ETA:

Guess I forgot to update with a photo after doing the MS04 on a custom 1 ounce mount

Very cool build! I've got a South Bend 9A lathe to mess around with, but I need to get my hands on a Bridgeport.

Chips require 610 DEGREES CELSIUS to ignite in air. Titanium POWDER is much less.

You are correct. Running a manual machine you tend to make powder a lot more often than you would on a cnc. You get that going it'll light the chips and good luck. I've seen it happen at work. Guy running a manual lathe and had to grab one of our special fire extinguishers to put it out.

So poly kits are on sale at Ares, guess I'll be forming my own opinion before long.

Thanks the tip.  Going to join you in this venture.