Posts Tagged ‘action’

FN SPR: Barrel

I took a short break from updating the blog since it is the only break I will get before my summer semester. I have not been idle and took a few short courses during the break. But now we need to look at the FN project again.


The setup work on the barrel is a repeat of everything that I did for the Mauser and Remington projects. After centering the barrel in the lathe, I cut the tenon and threaded the barrel to fit the receiver. The next step was to cut the cone for the bolt.

Cutting the cone

Cone complete

With the cone completed, I cut the chamber in the barrel. This rifle is chambered for .243 Winchester.  I tightened the action onto the barrel and it is now ready for test fire.

It fits!

Bolt open


Bolt closed

Time to do the test fire!

Test fire 1

Test fire 2

I am pleased with the test fire results. Case expansion on this rifle was 0.0005″ (12.7 microns/0.0127 mm). The final step of the barrel process is to cut the groove for the extractor. I marked the location of the barrel relative to the action, removed the barrel and set the barrel in a mill to cut the extractor slot.

Starting the extractor cut


During the cut

After I completed the cut, I re-assembled the action and barrel and verified the headspace and made sure the extractor works.

All lined up!

The only work left for the barrel is to do the crown. I will cover that in the next post on this project. As always, thank you for reading.


Remington 700: Fitting the barrel

Back to the Remington 700 project. I finished the barrel and the blueprinting of the bolt and the receiver. It is now time to fit the barrel and test fire the rifle. The masking tape you see in the photos is to protect the action from scratches.

Taped and ready to go

The Remington 700 receiver is easy to damage if twisted. To prevent damage like this I use a wrench adapter that I made during our first semester.

Wrench adapter

Once I installed the wrench adapter, I clamped the barrel in a barrel vice (yes, I made one of those in my first semester but the one you belongs to the school) and use an action wrench to tighten the barrel. Yes, the action wrench you see was a first semester project. Normally, I would use an a tool to hold the recoil lug in alignment during this step, but it was not needed as the action would be removed from the barrel after the test fire.

Ready to tighten

Once this was done, I installed the trigger and the rifle was ready to test fire.


Ready with bolt in action


Next was the test fire! Test firing consists of three rounds fired from the rifle. After the test fire, the cartridge cases are checked for expansion. We are allowed an expansion of 0.002 inches (0.0508mm or 50.8 micron). Here is a video of the test fire.

The results of the test fire was good. Zero case expansion. I am more than happy with that. The next step for this rifle is to install a muzzle brake and I will detail that in the next post.

Mauser project: Barrel, trigger and safety

As our semester is winding down, I am still playing catch up on posting my projects. Today, I will update some of the work I did on the Mauser. After completing work on the receiver and bolt, I am turning my attention to the barrel, installing a new trigger and a low position safety. I clamped the barrel and centered it in a 4-jaw chuck on the lathe.

Ready for cutting

After facing the barrel, I cut the tenon.


I then cut the threads needed to attach the barrel to the receiver including a relief cut at the shoulder part of the tenon. This is to ensure the receiver fits tightly onto the barrel. I verified that the face of the barrel was also touching inside the receiver. In the picture, I am busy reaming the chamber (.257 Roberts). The red marks you see is a marking fluid that I used to ensure all the metal surfaces that should make contact with each other is in fact doing so.


With the barrel chambering complete, I turned my attention to the action. First, I installed a Timney Sportsmen trigger. I also installed a Beuhler-style low safety.

Timney trigger

Close up


Once I completed this, I attached the barrel.

Ready for test fire

Ready for test fire


The next step for the action is to test fire it and check that the case expansion is good. I also have some other metal work to do and I will cover that in a future post.


FN SPR project: Blueprinting

It is time to talk and show some of the work I have done on my third (required) project this semester. The FN Special Purpose Rifle (SPR) is essentially a pre-64 Winchester 70 action. We managed to get a good group deal on these and I ended up buying 2 of these. One (this one) I will keep as a complete rifle as it will be part of my portfolio. At some stage, I will complete the second rifle and sell it. I will chamber this rifle in .243 Winchester and I will make a laminate stock for it.

FN SPR action

Ready to start


As with the Mauser and Remington projects, I start by blueprinting the bolt and receiver. I trued the bolt face first.

Bolt face

I also had to true the bolt lugs. No picture of that but the process is the same as for the Mauser bolt. I then trued the front of the receiver.


The only other step needed on the bolt and receiver was to lap the bolt to make sure there is full contact between the bolt lugs and the receiver. In my next post I will show the process of cutting and chambering the barrel.

Mauser project: The beginning

Even though the course require that I build a minimum of three rifles, an additional requirement is that one of these must use a military surplus Mauser action. There is many options available that can be used and the one I chose was M48A Mauser. These were built in Yugoslavia by Zastava and is a version of the FN designed Mauser Model 1924. Thank you to Matt for selling me the rifle for this project. I hope you like what I am doing with it. The rifle was in good condition and as I started working on it, realized that it had been refinished by an arsenal and had not seen much use since then. The only part of the old rifle that I need is the action and the bolt. I am building this rifle as a hunting rifle and when finished, will be chambered in .257 Roberts and have a one-piece wood stock made by me.

Please note that this work took place earlier this semester.

I started by disassembling the old rifle.

Action, old barrel and bolt

Then the action was mounted in a lathe and trued.

Truing the action

On the M48A action there is a bump on the rear of the receiver. It has a slot where cartridges on stripper clips can be inserted. However, this just does not look good. I removed the hump and smoothed the metal work.

Milling out the stripper clip slot

Although the stripper clip slot can still be seen, I am leaving it as such for the time being.

Action with hump removed

My attention then turned to the bolt. I started by heating the bolt handle and forging it into a new, more graceful shape. The picture also shows two tools I made in the first semester. Screwed in the back of the bolt is a bolt mandrel which (in this case) helps to draw heat away from the bolt body. The bolt sits inside a bolt bending block.

Forging the bolt handle

The next picture was taken during the process. I still needed to sweep the handle backwards a little.

Straight bolt handle

The next three pictures show the bolt handle after I swept the handle back, the receiver and how they fit together. I had to cut a small notch in the receiver body to allow the bolt to fully close.

Bolt and receiver


Action open


Action closed



So far, so good!