AMD-65

Finally got a kit from Centerfire Systems and began the build process.

• Disassembly 
• Build
• Finishing

Disassembly

Barrel Pin

This was THE most difficult barrel pin I've ever encountered.  Reading the forums, seems like most all AMD kits are very very very tight fitting.  On mine, I had to use an old barrel pin to start the pin moving.  After the tell-tale "pop" it moved quite easily.

Note the pin is moving here:

Complete:     

Observation:  There is actually some rust on the pin and in the pin hole.  I suspect this is what makes the AMD barrel pins so difficult.  On all of my AK-74 kits, the pins moved literally without any effort...

The AMD pin is on top, the pin I used to start it moving is on bottom:   

Barrel Removal

This was a royal pain.  I could NOT make the I-beam method work.  Had to use the BFH method.  Note that I figured a way to use the hammer without putting fingers at risk:

Put a glove over the barrel "just in case" it pops out hard: 

Note that I hammered using the side of the hammer - more area and less likely to miss the bolt!!!

Complete: 

Many pennies gave their lives to make this happen:

There is a minor scratch where the barrel hit the vise.  I noticed this and corrected by re-wrapping the rag around the barrel when it started to move:

The Build

Muzzle Extension

Trying out my new Flux (gasless) MIG welder on my muzzle extension.  This has to be permanently attached because the AMD-65 has a short barrel, and to meet the minimum legal requirement of 16+ inches, you must use an extension.  I am opting to use the original muzzle brake.

Note that BATFE requirements state that you can use 4 spot welds around the muzzle device, or one weld around half the circumference.  I chose the 4 spot welds as that will be easier to clean up and look cleaner.

I am using a Tapco muzzle extension. 

First weld - extension and brake:

Drilled a hole in the extension so I can weld to the barrel threads:

Second weld - extension and barrel:

    After the weld:         

I have a blank that I drilled for a standard AK-74 rear trunion.  Due to the fact that the AMD-65's rear trunion different hole locations, I am welding up the original holes and will dremel them flat.

Testing on a Bulgy receiver section from an older '74 kit.  This confirms that I *can* weld up these holes without burn-through, since the Bulgarian receiver is slightly thinner than the Ace blank I am welding.  The Ace is just under 16-gauge 4130 steel:

To prevent over-heating, the wire feed is set to a faster speed:

Working.  Now to do some dremel work:

Thanks to scubadvr and sks_hunter I was able to locate "anti-spatter" spray treatment.  This leaves a film over the metal that keeps the little welding balls from sticking to the metal.  This will greatly speed up the cleaning/sanding exercise.  Thanks, guys!  I picked up a can of the Anti-Spatter spray from Home Depot.  It is packaged in a red spray can under the Lincoln label.  I think it is made by another company, however.

The rest of the welds are now completed:

I used the Dremel sanding disk to make it smooth:

Final pass - I filled in the gaps with an Epoxy.  Then I just filed down - slowly - by hand until smooth, and touched up (gently) with a flapper sanding wheel.

Trigger Guard Assembly

This is my first effort with my new Harbor Freight 12-ton press.  I was pleased with the results.  My apologies for the blurry pics.  The lighting in my garage isn't the best & made the autofocus go screwy...

Rear Rivet

Front Rivets

Sanding the sides down in preparation for phosphating.  Note I used an angle grinder to finish the surface.

Phosphated, ready for paint!

Folding Stock & Swivel

Not readily evident in these pictures is the weld job I did with my MIG welder for the rear trunion holes - I had a pocket in one about the size of a large sewing needle, which I filled it in with JB Weld filler compound then sanded flush.

The template is available here.  I have confirmed it properly aligns with my build:

Factory swivel location is marked on the template.  

Before & after - I just used a spare buttstock swivel and judicious dremel work to finish it out.  I managed to bend the tabs on the inside with a pair of pliers, and made sure to bend both sides evenly, otherwise the 1mm thick receiver will flex and there will be a bend in the receiver - functional but not pretty.  Just take your time:

Take a larger drill and chase the top of the hole so the plunger will easily guide into the hole.  If this is not done, the folding stock catch may not be able to open/close smoothly.

Rear trunion rivets completed.  I am very pleased with the way the heads came out.  They look almost as good as the factory rivets, or the rivets on my AK-103 clone.

"Rear Done" -

Barrel Reinstallation

Since the barrel was so tight, I am chasing the bore within the trunion with a worn flapper wheel.  I am also resurfacing the barrel journal.  Not a great deal!  I am just brushing the flapper against the metal.  I am aiming for VERY small removal.  More of a polish job than a sanding job, really.

Update: "oops".  My polish job ground too much down.  The barrel is a slip fit and is loose.  Ideally, I can put this in the lathe and knurl it to raise the surface, thereby increasing the diameter.  After looking at the barrel attachments, I decided it would be too difficult.  What I did was to use my MIG welder and weld a very sloppy bead onto the barrel journal.  This gives me more metal to work with.

I used a hand file to file down the weld beads.  This is about halfway done:

I measured often.  Here is the final outcome:

That gives me a .004" press fit.  That's about right.

Pressing the barrel back in.  I put it upside down to start:

Braced the rear with wood blocks to keep it from canting.  It kept wanting to dip down.

I finished by turning over and pressing right-side up.

Oversized Barrel Pin

Due to headspace issues, I had to re-drill the barrel pin hole.  The hole is now oversized.  Lucky for me, I have a lathe and a grade-8 bolt.  I turned the bolt down to make the pin.  The pin is .002" oversized for a solid press fit.  Making the pin:

Complete:

It is starting to look like a gun again:

Center Support

The center support is going to prove tricky.  I don't know how, but when my friend and I were setting the rails in preparation for welding, the left side slipped back about 1/4".  It appears to hand-cycle fine, but looks strange.  I am therefore milling the holes to ensure they are properly aligned.

Milling the hole:

Ready for the center support.

The center support went in without a hitch. 

Grips

I resurfaced the grips by using a propane torch to "sweat" the plastic enough to glaze the outside.  This burned off some of the blemishes, and created a hard surface to sand.  I sanded off with a brillo pad and re-glazed the surface.  

Too much heat and the plastic will scorch, and turn a dark brown caramel color.  While keeping the flame moving, I positioned the nozzle just so the tip of the flame was about 1/2" away from the plastic.  When the plastic "sweat" I moved the flame away.

Before & after - note the right grip - the "wet" looking area is where I sweat the plastic.

This makes the relatively soft AMD grips maintain a "hard" finish that is actually more durable since it will be more resistant to abrasion, and slightly easier to grip.

Painting

I finally spray-painted with Eastwood Under-hood epoxy.  We'll see how good it lasts... I sprayed when it was around 45 degrees so I'm not convinced it set well.  I may refinish it this summer, we'll see how well the paint cures.  I must admit I like the leather sling...

All that's left is to order another US FCG for US parts count compliance and I'll be set!

A glamor shot with my AK-103 conversion.  :)

[compliance parts]

1. receiver
2. hammer
3. trigger
4. disconnector
5. piston
6. muzzle extension
7. floorplates / followers > subject to change