.50BMG Receiver

DocPhelps · January 16, 2001, 11:09 PM

Does anybody have a copy of receiver blueprints for the .50BMG. I am currently building one for personal use but there are a few pieces that I would really like to have schematics for.
I bought the barrel from the Gun Parts Corp. out of New York, and I buy ammo from Knob Creek Gun Range, in Lou. Ky.
Originaly I wanted to construct the entire weapon out of 308SS, but was told that stainless would not hold up to the pressures of the big 50. But LAR Grizley makes an all SS rifle. Can anyone help me out with problem?
thanks

Jim V · January 17, 2001, 11:03 AM

DON'T, unless you want to talk to the BATF.

cuerno de chivo · January 17, 2001, 09:07 PM

it's perfectly legal to build a non "nfa" gun for personal use

DocPhelps · January 17, 2001, 09:29 PM

Right. I'm am building the weapon for personal use only with no intent of ever selling it. If I were building it to patent and sell then I would have to register it and stamp the Serial # that ATF sent me.

zot · January 19, 2001, 04:15 PM

I have a .50 cal barrel off a browning heavy MG,its got the whole chamber, barrel has been used, I'd go with some very
high strenth steel, what kind of bolt system would you use?
I thought a drop breech like a Ruger would be cool for a single shot,I don't know if anyone ever made a Mauser action
for this rd. I don't see why BATF would care as long as you
applied for a license to make a firearm,if you make it,it
is a gun and needs a serial number.thats the only reason BATF would be involved,unless .50s are considered anyother
weapon or destrutive device? maybe go to Batf website ,they
read all posts in here anyway and know who you are allready.
http://www.atf.treas.gov/

beemerb · January 19, 2001, 09:17 PM

Fred Wells in Prescott AZ makes a mauser style reciever for the 50 BMG.If interested let me know and I will get phone number for you.

29 toter · November 29, 2004, 10:27 AM

If you are looking for plans you might try an internet search for:
(1) Maadi Griphen (sp?) $125.
(2) "big 50" by Gunmetal designs $50
(3) Hyper Delivery Systems $150

Also look into the Fifty Caliber Shooting Ass. In any case the designs listed above will put you on your way to a 50 cal.

P.S. designs listed in order of dificulty. Hyper Del. requires an edm.

HUBEL458 · November 30, 2004, 12:47 AM

You can get a State Arms 50 cal action for $850.And if
the surplus barrel you have is right one it will screw in.
Might be cheaper than building and heat treating one.
715-366-2006. You can get a fancy McBros action for about
2 grand.Ed.

mikikanazawa · November 30, 2004, 02:04 AM

I have some PDF blueprints for the Maadi-Griffen, and a few others. Drop me an E if you want 'em.

Offhand, I'd say a stainless action would be okay. The barrel would have to be an ordnance steel. (Don't take that as gospel; I haven't done any calculations, just going off what I've seen.)

Watchman · December 3, 2004, 09:45 AM

Regarding using 308 stainless steel for a receiver...DONT do it.

It is not strong enough. The stainless steels that are used in the manufacture of rifles are of the 400 series, mostly 410 and 416 SS. These are "heat treatable" SS that have much higher strength after being properly heat treated. These will need to be heat treated in a proper facility, this is not something that one can do at home as it a pretty involved process.

300 series SS does not have enough carbon in them to harden.Thats the very reason that they dont rust. The 400 series does contain carbon and will rust if not properly cared for.

I have built a few Maadi-Griffen clones. One thing that you need done properly is the heat treatment of the action and the bolt. With the bullpup design of the Maddi, you are laying your face right on the reciever when you pull the trigger. If you value the way you look and you think that your family is better served by having you around to pay bills, make sure that the heat treatment part is done right.

For pictures of what you'll be getting into check here...
.50 BMG pics

If I can be of further help let me know, as I've been there and done that.

Harry Bonar · January 29, 2005, 02:48 PM

Dear Sir:
Watchman has it!
Let me mage one more remark. Virtually ALL rifles operate at approximately the same pressure parameters; probably modern arms operate at 50,000 cup to 55,000 cup (psi would be different, and there is no conversion factor to cup). Whether it is a 270, or a 150 mm, tank gun, they operate at approximately the same pressure parameters.
But Watchman has hit on something many gunsmiths don't; and that is heat-treating! You need a professional to do this; he needs to know the analysis (SAE or other number) of the steel he's heat treating. He needs a specialized furnace, pyrometers (temp. device) and the proper "quench" and then, he needs to know at what temp to "draw it to to get the proper "C" Rockwell for your purpose - to do this right takes knowledge of the steel and a host of other things - this is a reason I NEVER try to re-heat-treat a soft Mauser action - I'd only be guessing!
Good shooting and hope your project works out. Harry

January 17, 2001, 11:03 AM	#2
Jim V Senior Member Join Date: January 31, 1999 Location: SE Michigan - USA Posts: 4,038	DON'T, unless you want to talk to the BATF. __________________ *MOLON LABE* If it ain't metal, single stack & single action, it ain't a 1911 no matter what it looks like. 1911 Forum THE TUBBY CURMUDGEON

November 30, 2004, 12:47 AM	#8
HUBEL458 Senior Member Join Date: March 8, 2000 Posts: 751	You can get a State Arms 50 cal action for $850.And if the surplus barrel you have is right one it will screw in. Might be cheaper than building and heat treating one. 715-366-2006. You can get a fancy McBros action for about 2 grand.Ed. __________________ ED HUBEL

December 3, 2004, 09:45 AM	#10
Watchman Junior member Join Date: August 8, 2000 Location: ARKANSAS Posts: 484	Regarding using 308 stainless steel for a receiver...DONT do it. It is not strong enough. The stainless steels that are used in the manufacture of rifles are of the 400 series, mostly 410 and 416 SS. These are "heat treatable" SS that have much higher strength after being properly heat treated. These will need to be heat treated in a proper facility, this is not something that one can do at home as it a pretty involved process. 300 series SS does not have enough carbon in them to harden.Thats the very reason that they dont rust. The 400 series does contain carbon and will rust if not properly cared for. I have built a few Maadi-Griffen clones. One thing that you need done properly is the heat treatment of the action and the bolt. With the bullpup design of the Maddi, you are laying your face right on the reciever when you pull the trigger. If you value the way you look and you think that your family is better served by having you around to pay bills, make sure that the heat treatment part is done right. For pictures of what you'll be getting into check here... .50 BMG pics If I can be of further help let me know, as I've been there and done that. Last edited by Watchman; December 3, 2004 at 02:59 PM.

January 29, 2005, 02:48 PM	#11
Harry Bonar Senior Member Join Date: December 5, 2004 Location: In the Vincent, Ohio general area. Posts: 1,804	re-50cal. Dear Sir: Watchman has it! Let me mage one more remark. Virtually ALL rifles operate at approximately the same pressure parameters; probably modern arms operate at 50,000 cup to 55,000 cup (psi would be different, and there is no conversion factor to cup). Whether it is a 270, or a 150 mm, tank gun, they operate at approximately the same pressure parameters. But Watchman has hit on something many gunsmiths don't; and that is heat-treating! You need a professional to do this; he needs to know the analysis (SAE or other number) of the steel he's heat treating. He needs a specialized furnace, pyrometers (temp. device) and the proper "quench" and then, he needs to know at what temp to "draw it to to get the proper "C" Rockwell for your purpose - to do this right takes knowledge of the steel and a host of other things - this is a reason I NEVER try to re-heat-treat a soft Mauser action - I'd only be guessing! Good shooting and hope your project works out. Harry

January 16, 2001, 11:09 PM	#1
DocPhelps Junior Member Join Date: January 16, 2001 Location: Backwoods, KY Posts: 2	Does anybody have a copy of receiver blueprints for the .50BMG. I am currently building one for personal use but there are a few pieces that I would really like to have schematics for. I bought the barrel from the Gun Parts Corp. out of New York, and I buy ammo from Knob Creek Gun Range, in Lou. Ky. Originaly I wanted to construct the entire weapon out of 308SS, but was told that stainless would not hold up to the pressures of the big 50. But LAR Grizley makes an all SS rifle. Can anyone help me out with problem? thanks

January 17, 2001, 09:07 PM	#3
cuerno de chivo Junior member Join Date: July 6, 2000 Posts: 919	it's perfectly legal to build a non "nfa" gun for personal use

January 17, 2001, 09:29 PM	#4
DocPhelps Junior Member Join Date: January 16, 2001 Location: Backwoods, KY Posts: 2	Right. I'm am building the weapon for personal use only with no intent of ever selling it. If I were building it to patent and sell then I would have to register it and stamp the Serial # that ATF sent me.

January 19, 2001, 04:15 PM	#5
zot Senior Member Join Date: April 2, 1999 Location: U.S.A. Posts: 566	I have a .50 cal barrel off a browning heavy MG,its got the whole chamber, barrel has been used, I'd go with some very high strenth steel, what kind of bolt system would you use? I thought a drop breech like a Ruger would be cool for a single shot,I don't know if anyone ever made a Mauser action for this rd. I don't see why BATF would care as long as you applied for a license to make a firearm,if you make it,it is a gun and needs a serial number.thats the only reason BATF would be involved,unless .50s are considered anyother weapon or destrutive device? maybe go to Batf website ,they read all posts in here anyway and know who you are allready. http://www.atf.treas.gov/

January 19, 2001, 09:17 PM	#6
beemerb Junior member Join Date: October 2, 1999 Location: AZ Posts: 1,759	Fred Wells in Prescott AZ makes a mauser style reciever for the 50 BMG.If interested let me know and I will get phone number for you.

November 29, 2004, 10:27 AM	#7
29 toter Junior Member Join Date: November 29, 2004 Posts: 1	If you are looking for plans you might try an internet search for: (1) Maadi Griphen (sp?) $125. (2) "big 50" by Gunmetal designs $50 (3) Hyper Delivery Systems $150 Also look into the Fifty Caliber Shooting Ass. In any case the designs listed above will put you on your way to a 50 cal. P.S. designs listed in order of dificulty. Hyper Del. requires an edm.

November 30, 2004, 02:04 AM	#9
mikikanazawa Senior Member Join Date: September 26, 2004 Posts: 449	I have some PDF blueprints for the Maadi-Griffen, and a few others. Drop me an E if you want 'em. Offhand, I'd say a stainless action would be okay. The barrel would have to be an ordnance steel. (Don't take that as gospel; I haven't done any calculations, just going off what I've seen.)