Early last year I bought a metric pattern Imbel FN-FAL parts kit that is believed to have come from Chile. It is one of those rifles that looks like it has been carried a lot, but fired little. Parts and bore look very good. The finish is unimportant since I will completely refinish it.
I've waited about 6-7 months to get a DS Arms upper receiver to complete the rifle. Research suggested that DSA made the highest quality receivers. I ordered mine with a cut for the carry handle. Yesterday I finally got my upper receiver after fhp-490 handled the transfer for me.
So, here is what I have.
The major parts.
An idea of what the rifle will look like when assembled.
Notice the rear of the barrel has a piece of the original receiver attached and will have to come off so the new receiver can be installed.
Here is where the upper receiver attaches to the lower receiver and butt stock.
What would an assault rifle be without a bolt, bolt carrier and charging handle?
There is a lot of work ahead of me. I'll continue to post here and update the project. This should be fun. To be legal in the US this rifle will have to contain 7 parts made in the US. For this build those parts will be something like gas piston, gas tube, hammer, sear, trigger, pistol grip, furniture.
In about 6 months the upper receiver should arrive for my Austrailian L1A1 build.
I took my barrel and receiver to the machine shop of gunsmith Russ Fritz (fhp-490) so he could do the machining needed to time the barrel to the receiver. Russ had his big lathe pretty much set up and waiting for my job.
Perhaps one thousandth of an inch had to be removed from the torque shoulder of the barrel so it would align with the receiver properly when tightened. In other words the front sight had to be perfectly vertical and the extractor notch had to align with the extractor. That's what the lathe was used for.
The barrel in front of the sight was placed in the chuck.
The breech end needs to be secured and steadied during turning. One way to do this was to just run the live center into the chamber. Russ had a more innovative method which also protected the chamber from possible damage from the live center. He previously chucked and center bored a .308 dummy round to insert into the chamber and the dummy round would accept the live center. Take a look at the prepped dummy round.
Here is the breech. You will see the dummy round inserted into the chamber that the live center will go into and help steady the barrel while turning.
When the tool is cutting it is much easier to see what it is doing if you color the metal area being worked on with a stain called Dykem. It's a liquid that just brushes on with a self applicator.
Cutting the torque shoulder. Go easy and only take a little off at a time and check your progress by screwing the receiver on.
A posed shot showing the relationship of the cutting tool to the torque shoulder.
Here is the tail stock and tool assembly in cutting position.
Check your work frequently. Russ (left) with micrometer. He's mic'ing the barrel flats so he can modify a 1-1/16" open end wrench to fit on and tighten the barrel. Me (right) with the receiver to check barrel timing.
This dark picture shows the barrel timing to be at 11:00 o'clock, exactly where it should be after the lathe work but before tightening the barrel.
Today was assemble the FAL day. I headed over to the gunshop of Russ Fritz (fhp-490) because I needed two specialty tools machined so the FAL barrel would be timed correctly with the receiver. In other words screw in the barrel and have the front and rear sights line up correctly when done.
I needed two timing tools made.
One was a 1/4" diameter rod threaded on one end to screw into the front sight assembly. So Russ chucked an aluminum rod in the lathe, turned one end down to the right diameter and threaded it 12x28.
The second tool was more involved. It was an aluminum block that would secure in the upper receiver with a 1/4" rod sticking up precisely dead center. So Russ mic'd the inside width of the upper receiver and then milled an aluminum block to the precise size. Then it was drilled through so a 1/4"x20 bolt could be inserted and tightened to secure the block in the receiver. Tho final process was to insert an aluminum rod into the block in the receiver so it was sticking straight up.
Picture the barrel being screwed into the receiver. For the final tightening of the barrel one rod stuck up from the front sight and one rod stuck up from the top of the receiver. When you could look down the length of the receiver and barrel and both vertical rods were as perfectly aligned (like sights) as the eye can tell, then stop tightening the barrel. It is timed to the receiver and hopefully when the rifle is assembled both sights will be lined up and the front sight isn't canted over to one side.
Here is the rod for the front sight being threaded.
This is how the inside of the upper receiver is measured with a micrometer to determine how wide to machine the aluminum block.
Coat one side of the block with Dykem and scribe a line at precisely the right width.
Carefully set up the block in a milling machine and mill it to the proper width to fit in the receiver.
When the block is the correct height and width use the milling machine to bore a hole into the block exactly in the center. This hole will hold the rod.
Then drill a hole all the way through on a drill press for the retaining bolt to go through. I can't find this pic, but I bet you get the idea.
Here is the rod installed in the front sight.
Here is the aluminum block secured in the top of the upper receiver with the rod in it from the top.
Receiver block from the bottom.
Then clamp the receiver wrench around the front of the receiver and put it in a big vice, tightly. Screw the barrel in and put a wrench with a cheater bar on it for leverage. You're going to need leverage to do the final tightening on the barrel. When the front sight rod and the receiver rod line up you are done. This shows the position of the rods after tightening the barrel into the receiver.
When I got home it was time to assemble my FAL. Here are the main parts groups.
Front portion of the rifle with gas tube installed and then the handguards.
Lower receiver and buttstock assembly.
Finally the rifle is assembled. It's not head spaced yet and of course it isn't refinished.
It is now US compliant with a minimum of 7 parts made in the US.
Upper Receiver
Trigger
Sear
Hammer
Gas Piston
Pistol Grip
Cocking Handle
I could replace the plastic furniture and have 9 US parts.
Special thanks to:
Russ Fritz (fhp-490) e-mail (omega386 at windstream.net) for his skills as a machinist and gunsmith. He is THE man to contact for any gunsmithing in my opinion. We've worked together on a number of special projects.
Court from the FAL Files and right here. The barrel timing tools were his idea. http://www.falfiles.com/forums/showthre ... adid=59621
To headspace, the bolt has to be removed from the bolt carrier and the extractor has to be removed from the bolt. I also removed the firing pin because my Go Gage was a live .308 round and I didn't want to take the chance of having an accident. I am accident prone and manage to slip with tools, gouge my fingers and hands and drop small parts which are never seen again.
I determined that the bolt would slide forward and close on an empty chamber.
When I inserted a cartridge into the chamber I discovered that the bolt would not close all the way. I needed more headspace. This photo is exaggerated for illustration.
So I drove out the locking shoulder. That's FAL speak for a pin that goes through the receiver and has a square corner (shoulder) on it that the rear of the bolt locks against when the bolt is in battery. The vernier calipers read that the locking shoulder was 61 thousands thick. The shoulder had to be made thinner or a thinner diameter pin installed. I didn't have the luxury of different pin sizes on hand so I opted to file the shoulder down by hand very carefully. I put it in a vice and used a hand file to carefully take off some thickness maintaining a flat surface and a uniform thickness.
My first attempt reduced the locking shoulder diameter to 55 thousands. I drove it back into the receiver and again tried to close the bolt on a round. It was closer, but not good enough.
So I drove the shoulder out again and took it back to the vice for a little more file work. I do mean a little. We're talking about a few thousandths of an inch. Back to the rifle and the calipers showed the locking shoulder thickness was now 50 thousandths. I have removed 11 thousandths of an inch total.
I slid the bolt forward on a round in the chamber and it closed all the way and was locked into battery!
The pencil is pointing to the locking shoulder.
The rear of the bolt must drop down and lock against the bolt shoulder. When it is right it looks like this. The pencil is pointing to the location.
Now it was time to insert my .308 No Go Gage and try closing the bolt on it. I couldn't find my gage. It wasn't with the other gages I keep on hand. Nuts. But, I think I am OK. I'll find or replace the gage by next weekend before I go to the range.
I still can't find my .308 No-Go Gage.
So I used an old expedient method to see how close I am with my headspace.
I checked to see how the bolt closed with a live round and a live round with one layer of plain masking tape on the head of the case. I also used cartridges of different manufacture.
For more variety I used the bolt by itself, the bolt in the bolt carrier and ever the bolt in the carrier and the firing pin in.
The extractor was out for all tests.
All combinations closed on the variety of bare cartridges.
None would close fully on the cartridge with the masking tape.
I think I'll be OK.
Today was the day to test fire my FAL build so I loaded up and headed to the range.
I set up on a bench rest and put a target out at 25 yards. The rifle and sights had been completely disassembled so I had no idea where it would shoot.
With the rifle clamped in the rest I chambered one round and reached up from under the concrete table top and squeezed the trigger. It went just fine. Uh, of course. I fired a few more rounds that way and examined the ejected brass. They all looked very good.
So it was time to shoot that rifle and see what it would or wouldn't do. I loaded one round at a time at first. Then two rounds and finally five rounds. If the rifle was going to go full auto on me I wanted that to be as controlled as possible. But it didn't. It shot semi-auto every time. Slow fire and rapid fire.
Ready to shoot.
This is the ammo I fired. Austrailian military surplus .308.
Here is a sample of the fired brass. No buldges, cracks or primer issues.
Here are my first shots at 25 yards. The first group is at 6:30 in the white. What a surprise! The target is an SR-1 which is for 200 yard shooting at 100 yards (it's reduced in size) and is a good target to practice on if you want to shoot in military rife shoots like the Garand and 1903 matches. The black bull is 6" diameter.
I made a few sight adjustments and was shooting in the black at 5:30.
Moved the same target (above) holder out to 50 yards and fired the remaining group labeled 50 yards with the line pointing to hits.
At 100 yards the lack of group was entirely me fault. I can't see to shoot iron sights well at that distance.
These are just a few pictures that I like.
This is the majority of the hand tools I used on this build.
My extractor removing tool. A big vice grip clamped on an M-16 fiing pin. It worked great for retracting the extractor plunger and spring.
I stripped the rifle down after shooting it to see if anything bad happened inside. It was A-OK.
This brings my FAL build to a conclusion. It was a good project.
Thanks for looking.
