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More on the Sudanese AR-10

Chuck — Fri, 20 Mar 2026 17:25:45 +0000

With the last test model machined I started putting the lower together and a number of issues were noted. The receiver dimension is correct for the holes, magazine release, magazine well and overall length and width. the magazine button and release lever are not deep enough.

These are the noted problems.

The first one is a very slight radius issue on the rear of the receiver just prior to the buffer tube

The second issue concerns the magazine release lever. this needs to be cut deeper to allow proper fit.

The third issue deals with the hole for the selector. There is a slight inset in the receiver to all the selector to set properly and this needs to be cut in. This is how it looks on the original.

And you can see it is missing on my test receiver.

The last issue is raised portion of the receiver around the magazine release. On my receiver it extends to far over and does not line up with the upper receiver properly.

With some minor changes to the machining program I hope to correct these issues.

Why it is necessary to run a test part after changes to the program

Chuck — Fri, 27 Feb 2026 23:15:29 +0000

A number of changes were made to the Sudanese AR-10 lower receiver. Selector stops were added and a new profiling program was used to allow for a better finish around a few areas of the receiver. Then a second lower was machined out of 6061 to verify the changes. During the process of machining a few issues were notes. The first is that with the new tool path it left on a thin section of metal.

The magazine release button also changed from an inside cut to and outside cut.

The other issue that was found was that the selector stops were located in the wrong spot.

All the issues have been corrected and checked. Next is to design a logo and write the printing program then start making Sudanese lower semi receivers.

Machining the Sudanese lower receiver op.2 and op3

Chuck — Sun, 08 Feb 2026 00:49:38 +0000

With op 1 completed it is now time to work on op 2 and 3. First a fixture needed to be machined to hold the machined receiver to all finishing the other side.

The machined op1 piece was set in the fixture and tighten down

All the holes were drilled in op1 so now the bottom was milled off and the receiver was contoured.

When the second side was complete receiver was removed and debured and parts were checked for proper fit,

The magazine release was checked for proper fit.

Op 3 was conducted, out of house, This is where the magazine housing was edm. it was then checked with a number of magazines to verify proper fit.

Next post will be about op4

machining the Sudanese lower

Chuck — Sun, 01 Feb 2026 19:22:49 +0000

Now that I am back into the shop it is time to get back to projects that was started years ago. The first project on the list was the Sudanese lower receiver. It had been drawn up in a solid model years back when the modeling program that was used in the shop was Solis Works, however due to the cost I shifted modeling programs and we now use Fusion 360. The model was moved from solid works to fusion 360 but you do not get any of the steps or even a drawing. All you transfer is the solid model. Some changes can be made to the solid model but it is not an easy task.

The first step was to write a cam program. With a friends help this was accomplished.

With the program written it was time to set up the HAAS machining center. All the tools were loaded and touched off and the program loaded.the first op was ready to go.

This is a test run and this receiver will be destroyed due to the material is the wrong material. The actual receiver will be made out of 7075 aluminum and the test piece is being made from 6061 aluminum. 6061 is about 1/3 the cost of 7075.

This photo shows the completion of op1. To deal with all the surfaces on the receiver there was a lot of fine detailed machining, generally referred to as surfacing, here are a few pictures that shows some of the finer details.

The radius on the front of the receiver magazine housing.

The detail around the magazine release.

A view of the tool paths.

The next post will be about op 2

VG1-5 update

Chuck — Fri, 01 Nov 2019 13:33:51 +0000

The first 5 rifles have been made and tested, then re-tested, then again photographed and re-tested and finally photographed in slow motion and re-tested. I number of interesting issues were found and collected, not serious but still interesting. We have one more test to do to verify that everything is good to go.

These are the next 9 rifles. All the changes that we made on the first 5 are being incorporated in this group. The upper receivers are being worked on.

At this set we are setting up and machining the ejection port. The port is being lengthen slightly and beveled.

This actually two different cuts. This is the tool to make the slight radius cut.

The set up was changed again due to a chatter issue that showed up.

A close up of the new look for the ejection port.

The new ejection port cut in and radius

3D Printer

Chuck — Fri, 03 Jun 2016 08:00:30 +0000

After seeing what Orin, a friend of gun lab, was able to accomplish with his printer I decided to take the plunge and obtain one for myself. I had previously look at this same model of printer a couple of years ago, however at 2500.00 it was out of my price range. At a cost of 270.00 plus shipping it was now in my price range and cheaper then the build it yourself models. Is it perfect no, but it does make a nice product.

It came package in a big heavy duty cardboard box.

With lots of great packing inside.

And with more boxes inside to hold the misc items.

Yet will all this careful packing some of the plastic parts were broke.

Saturday and part of Sunday morning was use to make new aluminum replacement parts. A quick drawing was made in solid works and it was out to the manual mill to make them.

Now this is a simple part to make , the base took a little more effort. It actually took longer then it was suppose to because I lost the first set I made. We spent a couple of hours this morning looking for them. So I now have spares when I find them.

The first action was to make a new base and install it.

In the process of doing that I managed to break another plastic part. It was not worth using any of the plastic components so everything was re-made into aluminum.

I am now back on track to getting the printer to work.

The next step on the MP-44 trunion

Chuck — Fri, 22 Apr 2016 08:00:13 +0000

Not that we have finished running the parts on the machining centers it is time to do the final fit up. Using the 1018 trunions that we made a hole was drilled in it to allow alignment with the button pressed into the receiver. Then the blocks were tested to see if the fit up was correct.

This is how the trunion looks away from the receiver.

As it sets into the receiver

An angle view at the rear of the trunion for proper fit up there.

A look at the front

Another at a slight angle.

Some de-buring still needs to take place and we still have a few cuts to do on the manual mill. If you are interested in any new MP-44 trunions please drop me a note and I will get the request to Pete.

MP-44 Trunion op7 , 8 and 9

Chuck — Thu, 21 Apr 2016 08:00:46 +0000

With these last three operations we will have completed the work on the cnc machining center.

You can see the process of rough machining the bottom of the curve for the trunion. This op also machined the complete magazine well out.

A good side view of the rough machining of the curve.

All the trunions finished with this operation.

The basic set up to complete this op.

This is op 8. All we are doing in this step is to finish cut the curve under the trunion.

OP 9 then goes in and cuts the top of the trunion.

These two pictures shows the top roughed out just prior to the finish pass.

This is how they look after the finish pass.

All the trunions after the finish of op 9

A close up of the trunions.

The next step in the manual mill

Update on the MP-44 trunions op6

Chuck — Wed, 20 Apr 2016 08:00:44 +0000

It has been a while for a MP-44 trunion update. The next couple of posts will get us back up to date with the trunion project.

The new op 5 was to cut a slot and rough magazine opening to allow coolant flow and chip removal and still allow us to high speed machine.

Well it did not work as well as we had hoped. The chip load was so great as it was not removed as fast as it needed to be so we still had problems with the end mill chipping. So back to the drawing board. The answer was to put the trunion on the manual mill and drill the hole much larger but still under size.

With the trunion on the lower left we did just that. What a difference that made. So now with all the trunions drilled with a larger hole we were back on track.

We were able to then finish machine the inside hole to meet specs. with a great finish as well.

A close up of the finish of the inside bore.

The new process worked great. No chattering or broken end mills.

Machining the MP-44 trunions op 5

Chuck — Fri, 25 Mar 2016 08:00:29 +0000

With this post I am going over a few of the problems that have occurred during the machining of op5 on the 4140 hardened trunions. We ran into a snag while doing this op. A problem that did not occur on the 1018 steel parts.

A quick video discussing the problem and solution.

The problem is that we just broke our second 4″ solid carbide end mill.

This one being brand new.. Something need to change in the process that we were using to make the 4140 trunions. The problem as far as we can determine is chip load up that did not happen while cutting the 1018 blocks. Now the new procedure is to cut a slot down the top of the trunion.

This slot and the next op will allow for more coolant flow into the part and better chip removal away from the cutter.

This is the set up for the this op.

Basic and very functional.

This new procedure was just started and we are well on the way to being back on schedule.

This new method as reduces the chatter that we had to deal with.