Making my own parts.

[Lonesome Dove]

So you're turning a crappy pin together rifle into a screw together rifle. I like the way you think.

 

[Gordo]

So, now that the 7.62x39 AR is together, I mounted the scope.
A SIG Whiskey-3, 4-12 x 50mm.
I like things like flip up lense covers, sun shades, and the KillFlash anti-reflection inserts.
Bad thing is finding add-ons for a particular scope.

When I bought the scope, I asked SIG what they had for accessories.
They have are mounts, and custom turrets, nothing else.
Asked them what the thread size was, and they did provide me with that info.
It turns out that the Vortex Viper 50mm has the same thread, so I had picked up one of their sun shades, and then cut it in half.
That sucker was 4" long, and looked retarded on an 18" AR.

Lens covers were not an issue, and Buttler Creek had what I needed.

But a KillFlash was another issue. There was nothing.
The no-name ones from china on eBay, listed as 50mm have no specifications as far as thread size, and others that looked to sit in a rubber ring gave no diameter...

So, what I have used in the past, is a chunk of honeycomb material from Toyota/Lexus air flow meters, since I had some of it from years ago when I was importing car parts from Japan. Dug around in the shop, and found one.

Put a layer of masking tape on it, traced out the ID of the sun shade. Cuts easily on a band saw with a fine 1/4" blade, but can also be cut with a sharp Xacto knife. I cut them just a little bit large, and gently press the piece onto the sun shade, with a thin layer of epoxy.

Now that I have used up the last piece I had, the stuff can be bought from people like McMaster-Carr, in sheets, and now from the chinese sight Alibaba, and Aliexpress. You want about 1/8" cell size, and 3/8" to 1/2" thickness.

Edit: McMaster no longer has it in 1/8" cell size, damnit!

Lexus air flow meter:

Leftovers:

Finished 'FlashKill':

I will go around the bare edge of the sun shade with some flat black model paint, and a small brush next.

 

[Gordo]

Converted my Magpul bipod from clamp screws to hold it to a picatinny rail,
to a QD lever.
Hated the heads of the screws they used, button heads that they cut a strait screw slot into.

This QD lever assembly cost a whole whopping $15 to my door, and a couple of hours modifying the Magpul base to accept it.

 

[Gordo]

Had the 7.62x39 build out to the range, with GOOD Ammo (Winchester ball), and got decent groups at 100 yards, in spite of my hand tremors, and wobbly Magpul bipod

.

Was frustrating to be looking through the scope, and watch the cross hairs dancing, mostly side to side, no matter if I leaned into the bipod or not.
So.......
Went into the locks on the bipod, and found way too much slack in the pivot bushings.
Made a new pair, with the OD .010" larger, the ID .010 smaller, and narrowed up the length by about .005".

Took all the side to slide slack out, and tightened up the forward/rearward slack.

Now the noticeable slop is all in the extension legs.
The only way I see to take that out is to build them up with Gun-Kote, or Tech-Line moly.
But that is for another day...

 

[Gordo]

Next project in the planning stages, Oh No!

Want to convert my Armalite AR10 to gas piston, but no one makes a kit.
The Adams kit's gas block for the AR15 sits too low for an AR10, and there are no AR10 piston style bolt carriers that I know of.

I think I have the gas block figured out, just ordered a Midwest Ind. 'Tall' gas block, and with a little machine work, convert it for piston usage.

Plenty of material above the gas tube hole to do things with.

And of course, the action rod will be home brew again.

That leaves the bolt carrier...
Ideally I can find an Adams Arms striker key that replaces an AR gas key.

So if you know where one is hiding, please let me know.
Adams striker key Wanted.

If not, maybe try to convert a gas key, to a striker face, but am concerned with if would withstand the hammering.
Last option would be to make one out of something like W1 steel, and heat treat it.

 

[Mozzi]

Even though it's above my head it's an interesting read. I like your ideas and implementation. Keep updating us as you go along.

 

[Gordo]

Finally found an Adams striker key, but had to buy a whole kit to get it.
Also found another guy selling a light weight Adams AR15 bolt carrier, so grabbed it, so I have my striker key,
plus a complete AR15 kit that I can sell, and recoup some of my money.

 

[Lead Belly]

Really informative build write-up. I like how you let us follow your thought process.

Great craftsmanship, as well.

 

[Gordo]

Shifting gears here for a bit, as my AMT Hardballer is getting long in the tooth.
Looseness between the barrel bushing, and slide was causing the slide not going back into battery, due to the barrel bushing cocking sideways due to oversize bore in slide, and the hole being oblong.
Years ago the original bushing was replaced with a King bushing, then recently, after this issue came up, found a larger OD bushing, but didn't help at all, that bad machine work by AMT, and 30 years of me shooting it was just too much.

The plan was to go to a bull barrel, and eliminate the flopping bushing.
But the oversize hole in the slide, along with being oblong killed the idea of just buying a barrel, as the largest I found was only .710".
Said screw-it, and bought some stainless bar stock, and a Sig Commander threaded barrel. The barrel is Nitron treated, in the same family as Nitride, and DLC, which makes for a hard bore.
The threaded Commander barrel is just the right length, to come out flush with the front of the slide.

I'm going with a Wilson flat wire main spring, and the matching full length guide rod.
This requires a reverse spring cup, due to there not being a barrel bushing to retain the cup any longer.
Wilson doesn't have one drilled for the smaller diameter guide rod that the flat wire springs require, so I just drilled their standard.
Their cups are of the 'keyed' style, that fill in the slot between the barrel, and the spring bores in the slide.
Since the key forms part of the barrel bore, it needed to be fit first, so everything is concentric.
Not an easy job to do, seeing the rear of the spring bore needs to be enlarged by .032", to a depth of .375", and that requires running the boring bar through the front of the slide, the boring head then adjusted out, and the cut being made on the up stroke. Had to grind a 'tooth' on the boring bar, so it would cut on the upstroke.
Was too deep into making sure I didn't screw my slide up, and forgot to snap an image of that operation, but the set-up was still in the mill, so got one just now. That's why the barrel bore shows to be already finished.

Inserted the spring cup (a nice, tap into place fit), and bore the barrel hole.
Ended up with a .725" bore.

Notice I'm holding the slide with a layer of paper between it, and the vice jaws. This keeps from marring the finish on the slide.

Now that I had a nice bore on the slide, work moved over to the lathe to start on the barrel cone.
Sorry, no pictures, as again I was busy setting up the different steps, and and kind of designing on the run.
First, a pilot hole using a 31/64" carbide drill bit, then opened it up to a 35/64" (tap drill for .575x28 thread).
Then drilled, and reamed to .575" to match the barrel diameter, 2.25" deep, and then tapped the threads in the last half inch.
Last step was to turn the taper on the OD, and the very end to match the slide bore of .725" minus clearance .003".

The Sig barrel hood is too wide to fit the AMT slide, so I will have to narrow that before proceeding with the rest of the barrel fitting.

More to come...

 

[red442joe]

Now, that is Sweet!

Joe

 

[RiverRider]

GREAT thread, Gordo.

You're not only handy with your hands, but you're pretty damned good with your noggin, too!

I'd like to have acquired the skills you have, but I guess other things kept me too busy. Life is just too short.

 

[Gordo]

Thanks guys!

Always had a knack for anything mechanical, but I make up for it for being a complete dunce on many other things...
Like how to come out on top with an argument with one's wife.

We each have our own.

Anyway, the past 3 days kept me in white knuckle mode, fitting the barrel.
What a pain, especially working on this poorly machined AMT, where castings are off, and machine work was off. Hell when I was halfway through I noticed the slide doesn't even sit on the frame strait, After owning the thing for 30 years, this is the first time noticing it.

I don't know how 1911 smiths do it, but they must have a procedure, but this was a first for me.
All during this quest kept thinking 'God don't let me screw up'!
Don't trust anything I see on YouTube, but I can't say I looked for anything done by Wilson Combat, or any of the other people specializing in 1911s.

Anyway, it's together, and the temp is supposed to get up to 70°, so looking to get to the range.
Not 100% finished, as the barrel isn't crowned to my liking yet.
I will need to make an expanding barrel mandrel to do that, but it shouldn't be any worse than an off the shelf Sig.

 

[Gordo]

Too long since last post.
Trip to the range showed that the barrel was sitting too low on the back end, and having the firing pin sitting off the center of the primer enough to have more no-fire, light strikes, than ignitions.
Mostly due to a titanium firing pin being too short.
Never knew that there were 2 common lengths of firing pins, besides 3 different diameters.
Had the correct diameter (.093"), but it was like .035" too short.
That combined with it being half the weight, the back end not protruding through the retainer as much, and the off center hits on the primer made for several fail to fire instances.
Once I put the original pin back in, it lights off every time now.
Tried finding the long version in Titanium is next to impossible, so I will have to make one of those also.

Ordered in a special file to deepen the locking lugs on the barrel, as they measured shallower than the original barrel.
The file made for this job has smooth sides, so not to widen the groves, just to make them deeper.
What a grueling job!
But got through it with minimal hand cramps.

The file needed cleaning every 10 strokes, or about .0005" on the depth of the grove.
I was able to stop when I got the groves (2) .010" deeper.

Also crowned the barrel at 11°.
I cheated, rented a barrel crowning cutter from 4D Reamer rentals.
Wasn't the sharpest cutter I've ever had, but he did put on the pilot diameter I needed.
To buy better one in carbide with the correct pilot would have been $165 with shipping.
The rental was under $35, as long as I didn't damage it, and shipped it back within 7 days.
Didn't think of taking pictures, sorry...
But here is the muzzle now:

Back at the range, everything went well, until the front Millet sight went by-by.
After about 15 minutes on my hands & knees, digging through dirt, and old shell casings, found the little devil.

Notice that there were no chamfers in the holes for the staking to hold onto.
Another short cut by AMT. Millet calls for a .040" deep chamfer, so that the pins have a place to expand in to.

By the way, Millett hand gun sights are no more. When Burris bought them up, they discontinued all hand gun sights.
I now hate Burris. Millett sights were the cream of the crop, and came on a lot of different pistols. They will be missed.

The front sight could have been used again since the posts were never expanded correctly, but I always wanted one of their bright orange front posts. Thankfully, there is quite a selection floating around on GunBroker.
Their special dual crimp tool set isn't so easy to find, and the two I found were over $200, but I did find a used one on Craig's list up in Indiana, and the guy agreed that I must be trust worthy, and would ship it to me, as long as I paid with Zelle.
Got it for $100 shipped.
It even come with a drilling jig if you are putting their sights on a pistol that never came with them,
and a special cutter bit to put in the chamfer, so that your damn front sight doesn't fall off !

Anyway, the front sight is supposed to be here tomorrow, so hopefully I can put this one back into service.

 

[Gordo]

Progress

Chamfered the underside of the holes.
The cutter that came from Millett, gets inserted from the underside, then tightened into a drill chuck, and then spun.
Went fairly quickly.

I also had found one of Millett's orange post front sights in the correct height., so ended up with an upgrade

The picture doesn't capture how bright it is in low light.

Now to find one of their white outlined rear blades...

 

[Gordo]

Danm, forgot to follow up.
Found a white line rear blade, but what an ordeal to get it in!
Teeny weeny little snap ring (1) & springs (4), but that wasn't worst.
The rear blade needed to be hand fit.

Anyway, here it is.

Had it out to Lonestar Wednesday, ran 50 rounds through it of mixed ammo, and all went well.