Now that the NYATI is done its time to get real creative. I'm thinking of a .600 or .577 based on a shortened .50 BMG case. Anyone here ever heard of one before? I think 2600 fps or more as a design criteria with a 900 gr bullet should be easily obtainable.I'm thinking of a cartridge about 3.0- 3.5 inches long with a 30 degree shoulder AI style. The 50 BMG case is very attractive as it's excellent brass, its plentiful and there is alot of it for fire- forming. .50 primers will provide good ignition and I already have an action. I know a .700 has been done on the 50 case. All I need is a good cartridge design a reamer and a barrel. This sounds like real fun!-Rob
Posts: 6314 | Location: Las Vegas,NV | Registered: 10 January 2001
I'm sure you already know this, but make sure you get the OK in writing from the ATF before building anything over .510. Most standard over .510 calibers are already cleared, but a wildcat may need new approval.
Rob, Good to see that you are still typing and your retinas have not detached.
Back issues of the Fifty Caliber Shooters Association journal have dealt with this. There are ATF problems with necking up the 50 BMG, but somebody else has done this on the shortened and full length case in .620" and .700" bore size, and more. He had some load data and velocity data. I am in Alaska, my journals are in Kentucky, else I might be more helpful. Someone else might have them at hand?
------------------ RAB
Posts: 28032 | Location: KY | Registered: 09 December 2001
Go Rob! I don't know of any 600 or 700's, but I recall reading about a 338 on a shortened 50 case a few years back. I look forward to reading about your's too. Take care - Dan
Posts: 5285 | Location: Alberta | Registered: 05 October 2001
There was an article a year or two ago in Very High Power about just this subject. The gent had a 600, and several other calibers, on 50 BMG brass. He also explained the BATF requirements. You cannot legally do this type of work without prior BATF approval, the calibers are not normal sporting rounds and fall under "Destructive Devices" and are not covered by the normal FFL and manufacturers licenses. www.fcsa.com
Posts: 1055 | Location: Real Sasquatch Country!!! I Seen 'Em! | Registered: 16 January 2001
Besides the feds, you really need a hydraulic press to work the brass, which adds a whole new dimension to the fun. Other then that, you sure won't have the issue of gummy bertram stuff, and suitable actions will allow a suitably heavy gun.
I've long thought of doing a scaled up broomhandle mauser in 75 acp, using cut down bmg brass, the but fed issue kinda puts the kibash on such plans. I did make up a dummy round with a bullet turned from aluminum.
Posts: 7213 | Location: Alaska | Registered: 27 February 2001
I do remember seeing such an article in VHP but can't find that copy for some reason. I was checking the Regulations this evening about building a 600 and you guys are right that I will need prior ATF approval. This doesn't bother me at all since my day job involves a close relationship with the govenment and I'm a stickler about regulatory compliance. I'm going to be in Washington, DC next week and I think I'll drop by the ATF office and talk to them about this project. It would not bother me a bit to pay whatever they want to get an approval to go ahead. This is just a big experiment anyway! If any of you guys can find that article I'd really like to review it. I want to build something original not copy someone elses good idea.Thanks-Rob
Posts: 6314 | Location: Las Vegas,NV | Registered: 10 January 2001
Rob, I'll buy one mate A guy over here, Jongmans, was making quite a few calibres on the 50BMG from 375 up through 577, 600 and even a 727 custom.He's not working anymore. I'm going to ring his old stockmaker tonight and will get some details.
Regards, Karl.
Posts: 3533 | Location: various | Registered: 03 June 2000
The articles in VHP were titled "Wildcatting the .50BMG" and was in 2 parts (VHP 2000 #2 & #3). He used a shellholder action and used some pretty funky projectiles. If I remember, one was a aerodynamic 'target' bullet that weighed 2500gr or so. Looked like interesting stuff but like others have said, it needs BATF approval.
I have a drawing of a .620 rimless cartridge designed and built by a gentleman who I wcan name privately. I can fax you if you like. I think I also have the gentleman'sphone number. He told me that he built it on a military mauser action, one in the tube and one in the magazine. His rifle weighs 9.5 pounds! The cases are swaged 50 BMG cases with the rim turned down. He is willing to build barrled actions for $3500, but the idea of a 2 shooter did not appeal to me. He also makes dies for the cartridge.
No need to re-invent the wheel! (By the way, I heard that the denizens of sub-saharan Africa had not invented the wheel before Europeans arrived 300 years ago.)
I seem to recall that the BATF regs classify rifles with a bore diameter greater than .500 as destructive devices unless they are of a nature that they are "not likely to be used as a weapon". For example, 50 BMG target rifles weighing 28 pounds, side by side .577 NE rifles, a 4 bore and 8 bore SxS shotgun set made by Charles Daly, etc.
But for some reason the .500 Linebaugh got stuck and therefore could not become a .510 Linebaugh. I do not know the story there.
If you go ahead with the .620 project, I would be interested in piggy backing! Let us know what the BATF says.
Posts: 18352 | Location: Salt Lake City, Utah USA | Registered: 20 April 2002
I found the first part of that article in VHP but not the second. Darn it! I really like the idea of a 600 AI type of short cartridge. I think I'll start dimensioning the whole thing out and try and get an appointment with the ATF station head in Washington for next week. They have been very pleasant at least to me in the past. This concept makes a huge amount of sense from a case availability versus power level standpoint as well as the availability of the action. I would have a hard time believing that ATF would not approve this as a sporting rifle. I'll know more later. If anyone could find that article in VHP 2000 #3 or have any other info I'd love to see it. Please E-Mail me if possible.-Rob
Posts: 6314 | Location: Las Vegas,NV | Registered: 10 January 2001
quote:Originally posted by 500grains: (sic) But for some reason the .500 Linebaugh got stuck and therefore could not become a .510 Linebaugh. I do not know the story there.
(sic)
The 500 Linebaugh and the 50 AE are interesting examples of this law. The 500 Linebaugh is truly a .510" bore, but, the rifling is deep enough that a .500" rod won't enter the barrel. The 50 AE started out as a .510", but the rifling was shallower, and a .500" rod would enter the bore. So, the 50 AE was changed to .500". That's the story I heard.
Posts: 7213 | Location: Alaska | Registered: 27 February 2001
I remember reading somewhere that JD Jones of SSK Industries had a .50 BMG shortened and necked up to .700 cal. I checked their website out and there is a mention of something of the sort as well as of a .95 cal on a 20mm case. Perhaps you could e-mail them and find out. Good luck.
