Making my own parts.

[Gordo]

I want them MY way...

Always have, always will.

While tuning a few AR builds, got tired of not finding buffers that I liked.
Things like anti-tilt in a required weight range, or easily changing weights, or coatings I wanted.

Here are the latest batch:

The anti-tilt is done by using a modified titanium drain plug that engages the rear of the bolt carrier, but does not require both assembly pins to be removed to open the receiver.
Thread size allows changing weights without removing the roll pin that holds the buffer tip in.
When machining is done, wear surfaces get coated with KG Gunkote.

And as you can see, one of my shop helpers is sleeping on the job...

 

[Gordo]

The past 3 day I've been making a titanium op-rod for an AR15 7.62x39 piston operated build.
Using an Adams Arms piston kit, but damn, their steel op-rods are heavy!
This is a mid length, 18" barrel gun.
Their's weigh 2.2 ounces, Titanium is 1.15 oz.

Did the same for my .45 acp PCC when I built it, and it runs great.

Also, Adams use a short spring cup that sits on a mil-spec barrel nut.
I'm using a nut from a slim FF tube, so their cup wouldn't work, so made one out of bearing bronze that sandwiches between the nut, and the top of the tube.

 

[deemus]

Nice work.

 

[Gordo]

Yesterday/today finished final fitting of the new op-rod.
Adams recommends about the thickness of a business card of free play on the op-rod, I normally equate that with .020".
And on all of these I make, the bolt end is balled, and the bolt is dimpled, so there is no chance of the rod ever bending off to one side, locking everything up.
Not an issue with their hardened steel rod, but titanium isn't that hard.

 

[Gordo]

After making the bronze spring seat above, I started thinking that it could be more than just a spring piece.
Why not extend it all the way into the receiver, and have it also support the op-rod?

Here is why, That hole in the front of the receiver was not designed to have a piece sliding hack, and forth inside of it, it was just to support the gas tube. It is clover leaf shaped to also vent some of the gas that leaks by the gas key while cycling.

But on a piston driven system, there is no gas going to the bolt via the gas key,
and these 4 little tips that were only meant to support a non-moving part are 1) aluminum, and 2) hard anodized.
Not the best bearing surface, even with Adam's original harden steel, and nitrided op-rod, and even worse with a titanium rod.
Titanium likes to gall with any other metal, and especially a hard anodized surface, with minimal contact surface.

So, I made the 'spring seat' longer, and actually extend into the receiver, thus removing the little clover leaf hole, and increasing the contact area.

Just waiting for the correct crowfoot to come in, so I can bed the barrel, and time the barrel nut.

The lower is ready to go. Will get pictures of that up soon.

 

[leVieux]

<>

Gee, you are so far ahead of me that I don’t even understand.

Biut, the pieces look beautiful !

Carry-on !

leVieux

 

[Sam7sf]

Good machining and thinking.

 

[Gordo]

Thank you both!

 

[Gordo]

One of the things I never liked about the AR was the use of roll pins.
Then someone came out with the screw-in bolt release pin.
Found that Aero sold them, and bought a few, then tracked down both an aircraft length dill, and tap because standards were next to impossible, but the aircraft tools are around 6" long, and quite easy to use.

The CNC Grease Gun lower uses a completely different mag catch that is on the right side. But it didn't take much time to find a long set screw, turn most of it down to act as the pin body, and tap the receiver.

Then I seen reference to people doing the same for the forward assist retention roll pin.
Yesterday I ordered a small bag of 4-40 x 5/8" long set screws, as the hole in the receiver for that pin was nearly perfect to tap to 4-40, Today they hit the door (McMaster-Carr is super quick on shipping).
Took one, machined off all but .150" O.D. the threads, down to .093".
Just finished that conversion today.

Oh, Damn-it!
Look there, another roll pin holding the forward assist assembly together...
Well, looks like another mini project...

 

[V-Tach]

Nice work......

I don't see the need, but interesting.........

 

[Gordo]

Just personal choice.
Since I am constantly playing with these things, examining, cleaning, changing, I prefer to use a wrench to disassemble/assemble rather than using a punch.
With my shaking fingers, punches & ! don't get along too well.

Might try making a different style button for the forward assist.

 

[zackmars]

On your buffer, how are you dealing with the excess length? Cut down spring? Rifle/a5 RE?

 

[Gordo]

Went to A5 buffer tubes on everything.

 

[red442joe]

On all AR builds I have taken to using a set screw to trap the rear take down pin detent spring. Tap the hole 4-40, snip three coils off the spring, then insert a set screw that is about three threads long. Uses a .050" allen wrench, which goes with every build.

Joe

 

[Gordo]

Yup, have done the same.
Different on an Armalite AR10, that spring & detent go in from the bottom, and secured by the grip.