OK, too much story telling and too much texts. We need pictures!
This was the only two pictures I took during manufacturing period of the Christmas 2008. Believe it or not, the thing in the picture is the basic for the bolt head, with the firing pin hole just finished. The second is gas block, in 90% finished shape.
From now on the picture was taken between April 2009 to May 2009.
This is the 20 inch barrel before Christmas 2008. You can see it in the video, except this is before it is machined. I bought it cheap from an online retailer. When I first checked the barrel, I found the gas part bur was lodged inside of the barrel, and I couldn't push it out with a cleaning rod. I called to ask how I can deal with this. The guy said you can just shoot a round it will be out. I was skeptical but by then I was planning to work on it right away, so I didn't ask for a exchange. I shot two round out of it after I mounted it on my 7.62X39 AR15. It did DE-burred, just don't know if the barrel was scratched inside.
Billet used to make the upper receiver, 7075-T6 Aluminum. On Mcmaster it asks for $120, bought locally from Saperal (sorry if spell wrong) for just $40.
Some half done parts. Some of them didn't make it to the rifle you see. In it, there were piston, gas block, op rod interlink, upper receiver with barrel nut on it, and a locking ring to be the first one I discarded.
more picture.
Setting up to machine the barrel.
Start to turn down the profile. In my commercial design of the future (if I go that far at all), this is not necessary. I did this just for using the one AR15 A2 recoil spring I had in hand. Long story later.
Almost complete piston system.
You may notice the lathe I used in this picture is different from the one I used in previous two picture. There is a story behind it. The loathe I used in previous two picture belongs to my dear friend John. I also took my video shot in his garage. The lathe he has, compare to the lathe in my school, has better quality. This was why I do the barrel job in his shop. However, the shear pin that interlock the head with the cutter table was broken, so I can't cut thread on the barrel with his lathe. I don't trust the the lathe in my school to do the job (not a good judgement really), so I bought a die to cut the thread instead. This was one incident that showed I was an amateur. I didn't press the die before I turn it. It started with an angle and I didn't realize it until I couldn't turn it. The thread bite deep into the barrel and the thread cut looks like a snake. I thought this barrel is wasted.
My another friend Steve, who is also a friend of John, came to the rescue. He convinced me that any turning lathe is a good lathe and in terms of thread, as long as you have enough material left, it will do the job. We went to our school and I, under his instruction and supervision, got the correct thread back. Steve used to be a tool maker for McDonald Douglas and later Boeing. Like John and many other seasoned manufacturing expert, they lost their job due to various direct reasons, but nevertheless all accumulated to the fact that the manufacturing job in this country were shipped aboard. After several layoffs until 2006, Steve gave up his career as a tool and die maker, and find himself a prison cop job. He is still doing it today...
Continue,
The piston system mounted on an standard AR15 for a firing test. The op rod was not made yet and won't able to be installed anyway. I was initially hoping to shoot a video to see if the piston would circle. Well, the home camcorder can't do ****. In the end, I did feel the gas blowing backward toward me, so at least the piston went out of the gas chamber.
Start to milling the upper receiver. The complex hole was contracted out to be done by EDM. This is the only machining that wasn't done by myself, and not counting the airline ticket fee, this is single most expensive investment of this project as well. And the result? Absolutely worth it!
Start to look familiar?
Start to mill the upper portion.
This is the third bolt head I've ever made, and it is the one in the rifle you see. Base on the lesson learned before, I manage to pull this one off without a glitch. It is pretty much finished based on look. However, there were still more work need to be done, the extractor slot, ejector hole, ejector retaining pin hole, extractor pin hole, etc, to name a few. Unfortunately, this is not going to be the one that do a real firing test. It has excessive head space and it is doomed even before I start to make it.
As I stated before, I only had a 7.62X39 AR, so I didn't buy a new 223 bolt to be the reference due to the stingy reason. I was a poor student and I have to use the money wisely. I borrowed a 223 bolt from a close friend. But I didn't ask and he didn't bother to tell me either, that his bolt was a second hand one. Even he didn't know, let along myself, that that bolt was already worn out. Plus the measurement error, the result is that the bolt had excessive head space on the drawing board. Later when I told my friend about this, he tell me something that was even more interesting. Not long after I returned this bolt back to him, the bolt was split in half during a range trip. Again, he didn't tell me (not that he has to). Costly lesson! There are more stories associate with this bolt and allow me to share with you later.
Now, the completed bolt with the bolt carrier assembly. The bolt is on a left discharge position. As you may notice, the bolt hadn't been heat treated yet. The triangle-ish shaped bolt carrier was not intentional. It was a weight relieve cut on the carrier. The mill was set on auto feed and my mind slipped for about several seconds.
Time was running out fast. The main purpose of the trip, to get my doctoral degree, was fulfilled. However, completing the gun was not. By then, I had an international meeting I scheduled to attend in, coincidentally, Germany. Before that date, I only managed to have completed about 75% of the upper, while the lower wasn't even started. This leave concluded my more than ten years stay in the United States. This also means my hope of finishing this project had to be suspended indefinitely. This is life, you don't always get what you want. On June 3rd 2009, on my way boarding the out bound airplane, I was thinking Arnold, "I will be back!"