Homemade .50 caliber?

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Maser

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Was searching around Amazon.com when I found this book.
http://www.amazon.com/50-Caliber-Rifle-Construction-Manual-Follow/dp/1581603460

I have seen many of them types of books before and have a few of them myself, but of course I just have them for educational and entertainment purposes only. Anyways, the thought of building a .50 BMG is very intriguing to me. I know that's it's perfectly legal to build a conventional (single shot) gun, but do those laws also apply to a .50 BMG? The .50 caliber laws are weird so I was wondering if making that type of gun would still be legal.

You have to admit guys, building a .50 caliber rifle yourself has got to be the best home project there is. :cool:
 
Really? I always thought it was anything above .60 caliber (not counting shotguns) was then considered a DD. :confused:
 
Building a 50 BMG is legal if you can legally own one. (Not legal in CA anymore, though you can build other 50s).

Anything above 50 is a DD if it is not classified as a sporting cartridge. That's why you have 700 Nitro Express...
 
So if I buy an action that can house a .50 Browning, but give it a barrel that is chambered for a let say errr... 416-50 then it's all good? It's just a matter of time until Kali bans the 338 Lapua Mag. josh
 
I built one using that book. The book is vauge at best with some serious issues as far as tolerancing. I had to redesign several components to make it work properly. DON'T try it unless you're an experienced machinst with access to the proper equipment. It isn't something for the casual garage mechanic.

Here it is finished:


eu35o7.jpg
 
Well, that's one way to keep squirrels off of the porch and out of the bird feeders. :D

Seriously, nice job!
 
Very nice job!! that could pass as something factory made if you stamped a long number on the side... How's the accuracy on that?

What tools did you use to manufacture something like that? I can tig weld and work steel to some point but do you need lathes, or what kind of machine shop tools? I'm wondering what type of machine you used to get the ejection ports so perfect...
 
Very nice job!! that could pass as something factory made if you stamped a long number on the side... How's the accuracy on that?

What tools did you use to manufacture something like that? I can tig weld and work steel to some point but do you need lathes, or what kind of machine shop tools? I'm wondering what type of machine you used to get the ejection ports so perfect...
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Thanks everyone. It shoots around 1 1/4 MOA. I started with a standard seamless tube and cut the vent slots, ejection port, and the bolt slot on a Bridgeport. I took a spare M2 barrel and cut 6 inches off of each end and turned and threaded it on a CNC lathe. Next I made the firing pin, bolt, taper sleeve, muzzle break and bolt handle on a CNC lathe as well. Next I cut the cocking mechanism, trigger housing, extractor, and the bolt lugs on a Bridgeport. I then threw the bolt back in a 3 axis CNC lathe and turned and milled the receiver lugs (it screws onto the barrel). I fabricated the carry handle. There was no plans for a handle in the book.

Next I made the scope mount and buttstock parts. There were some more parts I made but I won't go into every single one.

I then welded everything together and honed the receiver tube out. Even TIG welding it put enough heat in it to cause some friction between the ID of the tube and the bolt.

Some of the things I redesigned were the extractor and cocking mechanism. The print called for one lug to be just about cut off to mount the extractor. I didn't feel like losing a third of my bolt strength so I made it to fit between the lugs. I also redesigned the bolt lengths. His prints didn't match up. The tolerances interfered with one another. I also made the cocking mechanism where you could disassemble it in the tube. I did this because if you cut the tube slot for the bolt all the way out of the end it springs open and you lose the fit. Plus it looks like crap. With the cocking mechanism a single piece you couldn't take it apart without the full length slot.

Another major problem was the cocking mechanism itself. The spring strength required for the firing pin would actually bind itself to the point that it would lock up when trying to open the bolt. (It cocks on opening). I made a guide for the back of the mechanism that holds everything in place. It now works very smooth.

It was a major PITA.:D

Now that I've done one and shot it there are several major improvements that I can make for the next one. If there is a next one.
 
so i can legally build a single shot rifle under .50 cal? Thats awesome!

..How about shotguns? could i build one of those? I'd like to try building a single shot 12ga, but only if its legal, of course.
 
That is a great looking 50. Mine is in the works. Own design based on the tube gun like yours.

What size tubing did you use? OD and Wall? Does your gun have an ejector, or just an extractor?

Thanks for the inspiration.
 
I spent $140 for the M2 barrel. The rest of the material will set you back around $100, give or take. The chamber reamer and headspace gauge rental was $75.00. All in all I have about $500 in it with scope, trigger, etc... The trigger is a Bold Mauser. I liked the idea of having an adjustable trigger plus I was just too lazy to make it.

The OD of the tubing is 2.25" with a .125 wall thickness. Make sure you get seamless. The tube is standard 1018 hot rolled with all the components either heat treated tool steel or 4140 HT. The only parts I heat treated were the firing pin and the receiver lugs. I believe you could build it without heat treating it as long as you use a high grade steel. I've put about 150 rounds through it and the headspace hasn't changed yet and no noticable wear on the bolt lugs. I thought about an ejector but decided against it. It's a single shot so a quick reload isn't a viable option.

jcaldwell, when you do yours I'd be happy to send some detailed pics of various components and some ideas for improvement over the original design if you want. The extractor was the most significant thing changed. When I made mine I had access to several pics of one that had been completed and it helped.

I'm toying with the idea of a modular tubed carbine that's mag fed. I'm waiting for the days to go to 30 hours and the weeks to get an extra day though.:D Having trouble finding a mag for it believe it or not. Looked at a Barrett mag but they're unavailable now and if they were it costs around $180. Ouch!!

RNF, I'm not versed in NC law but as for federal law you can build a shotgun provided you can posses a firearm, it meets all legal specs (18 inch barrel etc) and you never sell it.
 
Any pictures you could send my way would be great. Send me a PM with your email address if you don't mind.

I'm starting with 2.25" 4140, and building a slightly enlarged McMillan style 2 lug action. The big change will be the trigger mechanism, in order to make it easier to make. I'm thinking about going with a AR15 style trigger with a hammer. I also designed the action so it could be completely machined with a 1/2" end mill for the lug ways, so I don't need to broach or EDM.

I have all the facilities for heat treating, so I'll probably end up at RC 40-45, with the bolt just a little harder than the action.

With the small fortune I spent in BMG reloading equipment I'm fairly committed to this project now. Any help would be most appreciated.
 
Any pictures you could send my way would be great. Send me a PM with your email address if you don't mind.

I'm starting with 2.25" 4140, and building a slightly enlarged McMillan style 2 lug action. The big change will be the trigger mechanism, in order to make it easier to make. I'm thinking about going with a AR15 style trigger with a hammer. I also designed the action so it could be completely machined with a 1/2" end mill for the lug ways, so I don't need to broach or EDM.

I have all the facilities for heat treating, so I'll probably end up at RC 40-45, with the bolt just a little harder than the action.

With the small fortune I spent in BMG reloading equipment I'm fairly committed to this project now. Any help would be most appreciated.
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I'll send you a PM in a minute. Sounds like you have a good plan. The two lug setup will work fine. When you finish I want pics of the AR trigger. It's also a good idea you have about keeping the bolt lugs and the receiver lugs a different hardness. Otherwise you could have problems with galding if you get a tight round. I'll help in anyway I can.
 
Just started this project

So any advice for someone, i know this thread is kind of old however i figure why not ask? Any sources for a barrel other then the 400$ barrels i'm finding online?


THanks
 
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