Machining a square hole

[trotterlg]

For a long time I have thought about building a small single shot bolt gun from scratch.  What had me stopped was how to cut the slots for the bolt locking lugs without using a broach.  Guess I must be slow because it was just dead simple to do.  I took the barrel metal for the receiver and drilled a hole through it for the bolt body, then bored the front and rear the size of the barrel for threads allowing enough room at the front for the locking lugs.  Then I set up my milling attachment on the little lathe I have and cut one slot the length of the bolt body bore and the width of the locking lug.  Using an end mill that had the same diameter shaft as the cutting part, I just reached through the slot and, using it's sides for a guide on the end mill shaft, cut the slot in the other side of the receiver.  I will use the slot on the bottom for the trigger/hammer group to mount in.  Think I will use a captive type bolt that you just pull out and clip the round in the nose of it.  Probably will do it up in 22 Hornet just to stay with something low pressure.  Anyone else ever build up a rifle from scratch?  I would love to see some pictures.  Larry

[quickdtoo]

Ingenious Larry!! 

Tim

[Frank46]

Very good. Always wondered how to do that. Not to be off topic but thought the romanian cugir single shot 22 somehow could be converted to centerfire for something like 25-20 or 32-20. Thanks for sharing your machining skills. I believe that what you are referring to is what is called a "shell holder" bolt. In that the bolt has to be removed to take out the spent cartridge and insert a new one. Course you could make up an extractor similar to that on the 1888 commission rifle or 1891 argentine mauser to remove the case, and a spring loaded ejector like on a rem 700. Frank

[trotterlg]

You are correct, a shell holder bolt, they look like a dead simple solution for a project like this.  I did do a conversion of a Remington 581 to a CF 22 Hornet, and it worked out good.  Larry

[gunnut69]

How do you deal with BATF's regulations? They require notification prior to the build and what will you use for a serial number?? Where do you plan on getting the heat treat done.. What kind of material.. Looks like a great job...

[trotterlg]

Anyone can build a gun that is legal for them to own.  You don't have to notify anyone, just build it and have fun.  I may give it serial number one.    Larry

[Oldshooter]

Very nice Larry. Be sure to post some finish pics so we can really be jealous! I envy anyone that can machine precision equipment especially a firearm.

[JonD.]

For a long time I have thought about building a small single shot bolt gun from scratch.  What had me stopped was how to cut the slots for the bolt locking lugs without using a broach.  Guess I must be slow because it was just dead simple to do.  I took the barrel metal for the receiver and drilled a hole through it for the bolt body, then bored the front and rear the size of the barrel for threads allowing enough room at the front for the locking lugs.  Then I set up my milling attachment on the little lathe I have and cut one slot the length of the bolt body bore and the width of the locking lug.  Using an end mill that had the same diameter shaft as the cutting part, I just reached through the slot and, using it's sides for a guide on the end mill shaft, cut the slot in the other side of the receiver.  I will use the slot on the bottom for the trigger/hammer group to mount in.  Think I will use a captive type bolt that you just pull out and clip the round in the nose of it.  Probably will do it up in 22 Hornet just to stay with something low pressure.  Anyone else ever build up a rifle from scratch?  I would love to see some pictures.  Larry

I have definitely given it much thought.  I found this site you may be interested in: http://rkba.org/guns/boltaction/boltaction1.pdf  (Just enter in the next number into the address for the next chapter) 10 in all)

Anyone can build a gun that is legal for them to own.  You don't have to notify anyone, just build it and have fun.  I may give it serial number one.   Larry

As long as you keep it for yourself and never sell it or let the ownership change.

[trotterlg]

I think it is legal to will it to someone when you die, either way I guess you wouldn't really care.  Larry

[JonD.]

Where do you plan on getting the heat treat done.. What kind of material.. Looks like a great job...

4140 Pre-heat-treated has a Rockwell C hardness of around 40 or so(its been a while, so I don't remember the actual #) and can be machined. It is also one of the best steels to use for strength parts, like receivers.

[trotterlg]

This one is made from a piece of .410 shotgun barrel, the bolt body is made from a grade 8 bolt.  I am machining the fireing pin from some water hard drill rod so I can harden the tip and the part the sear rides on.  Larry

[bcp]

Don't need permission to build, don't need permission to sell.

But, it must be built for your personal use, not for sale.  It is legal to decide later to sell it.  You cannot "build it to sell" without a mfg license.

Bruce