I want to by a cz550 in 458 win mag. and than chamber it for a more powerfull 450. what is the best alternative rigby, dakota, walker, ackley, marsburn?

The most simple conversion would be to a 458 Lott or 450 Ackley. That would mean just lengthening the chamber and leaving everything else as it is. With the Lott, you could also still fire 458 Win. Mag. ammo in it (not really an advantage). For better performance I would recommend the 450 Dakota. This is based on the 416 Rigby case, so you would have to open up the bolt face and change some things in the magazine for reliable feeding.

Of course, if you were going the 450 Rigby route, you need to buy the CZ in the 416 Rigby instead of the 458 Winchester. It would make a much simpler conversion.

I think Bob's right on this one. Some Norwegian smiths refuse to convert the Brno to Lott because of feed problems. When I converted my .458 to Rigby, I had a lot of bells and whistles added that drove the cost up. Thinking it all over, I'd go with the .416 and just get a rebarrel done. You're going to have to have steelglass bedding, a barrel band swivel, big fat recoil pad, etc. done anyway, so saving money on the bolt face, follower, rails and such only makes good sense. This wasn't an option in '98.

Sarge

Do you want the most powerful 45 caliber rifle? Buy the CZ 550 Mangum in 416 Rigby and then re-barrel it to a 460 Weatherby. I am on the same boat right now and this is what I am planning to do. Good luck. Ming

I need to revise my comments. If this were my project (I would still go the Rigby route), I would shoot the 416 Rigby first. If it was a true MOA shooter with factory ammo, I would not rebarrel it to a 450 Rigby. This would be one of those rare factory accurate guns and it would kill me to monkey with. These are inexensive enough to buy a second one and check it's accuaracy. I would then rebarrel the least accurate of the two.

Otherwise, if it was just an average shooter from the very beginning, I would go ahead with the project.

FYI. The 450 Rigby is the 460 Weatherby without the belt. And trust me, it is plenty powerful. I have a 458 Lott and a 460 Weatherby. My 458 Lott loads move a 500 grain bullet at 2350 fps and my 460 Weatherby loads move a 500 grain bullet at 2680 fps. Factory Weatherby loads average 2625 fps. This is still too much. You can load the 450 Rigby down to 2400 fps with low pressure and it will be plenty. Especially if you do not intend on using a muzzle brake (which I dislike).

[This message has been edited by Longbob (edited 03-03-2002).]

As we all know by now, any 500 gr bullet at approximately 2400 fps will be close to optimum for any dangerous game that walks the earth. While more is fun, we know that actual field results demonstrate that higher velocities than 2400fps just plain don't work as well with .45 caliber bullets. Of course variables due to various twist rates and bullet construction will effect the veracity of my statement, nevertheless, I believe it to be true. This is why the old .416 Rigby albeit using a 400 gr bullet at 2400fps is such a great killer. I verified this myself in Tanzania and was absolutely amazed at how well it did. It is interesting to note, that the worst nightmare of any PH is the hunter who shows up with a 460 WBY with factory loads that they can't shoot!
To get to the point, get a CZ in either .416 Rigby or one in 458 win and convert it to a 450 Ackley or Lott and don't look back. If you can possibly swing the cash,look carefully at converting any pre-64 Mod 70 Winchester long action to 450 Ackley. I built one a few weeks ago ( and posted the pictures) and absolutely love it. Fantastic accuracy, feeding and ejection like on ball bearings and clasic looks and elegance. Another thought would be a 460 G&A on a Remington 700 with a Sako extractor mod. Remember though 2400fps is the magic number and all you need. Hope this helps.-Rob

[This message has been edited by Robgunbuilder (edited 03-03-2002).]

Rob,

I know what you are saying but you do not need to load the 460 WB all the way all the time. Wouldn't the 460 WB be operating at a lower pressure than the 458 Lott or other 450s with the 500 grain RN at around 2400 fps?

I got a 460 WB but it is a Weatherby rifle so I am looking to have a 460 WB in a CRF rifle. Anyway, I did not mean to argue but just wanted to comment on my previous comment. Thanks. Ming

Lotts, Ackleys, Rigbys, Dakotas, take your pick. The Rigby and Dakota have the edge on comparable velocities at lower pressures than the Lott or Ackley.

I am rechambering a 458 Win CZ550 to 450 Dakota now for a customer. The Dakota and Rigby are basically similar, use the same parent case (416 Rigby) but the Dakota has the edge on ease of obtaining brass, just buy it from Dakota.

Rob is absolutely correct, 2400 ft is enough with a 500 grain bullet. Forget the velocity hype and build a rifle, and loads, you can accurately shoot. And do not forget about the hot loads and hot temperatures and sticky cases, yep, it still happens in Africa, ask Hunter Jim about the failures of various rifle and cartridge combinations during the PH tests in South Africa last October.

If you have not yet shot a Lott, Ackley, Dakota, Rigby, or similar cartridge, using full house 500 grain loads, then I strongly advise trying one out before getting into a rifle you cannot handle. The recoil is certainly managable, but a first timer needs some practice and a rifle that is built properly. Read John Taylor's "African Rifles and Cartridges", his words still apply!

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Ming,

FWIW, I didn't think you were being argumentative. You just offered an alternative which should be considered. The advantages of the 460 Weatherby are the case capacity, factory loads, and available brass. The only disadvantages I can think of is the belt (rougher feeding and limits magazine room) and the factory loads are too hot.

The 450 Rigby has a couple of advantages. Plenty of case capacity and no belt (smoother feeding and more magazine room). Oh, and a coolness factor. The main disadvantage is brass availability. However, this is not much of a problem unless you are sadistic (most of us are). A couple of a hundred rounds of brass should last you quite a while after you find your load.

Shultz & larsen,

After all this help we have given you, it is mandatory that you keep us posted on your choices and progress. Pictures would also put you in our good graces.

I got used to my .450 Rigby slow and easy. Get a copy of Solo Safari by Cacek. Skip the idea that you might actually be able to safari without a PH, the difficulties are immense. Go directly to the chapter on how to get used to your Big Killer and follow them precisely. It works like a charm. As to the effect of big bullets at speed. My personal loads in the Rigby are 105 gr. of IMR 4350 for a chronographed 2280 fps. Now that I have GunJuiced the barrel, I expect to chrono a bit over 2300. That generates over 3 ft tons of energy. I can't imagine what animal you would shoot that needs more than that! Charging blue whale on the beach? That particular load knocked two buffalo DOWN. Right off their feet. Now I admit that the second did get back up again but he was sick and wobbly and didn't go far. Just make sure that your rifle weighs at least 10 lbs. and has a REALLY fat recoil pad. Oh, and by the way, when you get the beast sighted in, get off the bench. You won't find any in Africa and big rifles are a lot less unpleasent to practice with off shooting sticks.

Ming,
My loads come from Dakota who got them from Weatherby.

Sarge

[This message has been edited by Oldsarge (edited 03-04-2002).]

Thanks Bob and Sarge for your reply. It seems like most people would find a reason to dislike anything from Weatherby. I don't care for their non CRF rifles but I am facinated with their cartridges. The 460 WB is one of my favorites because I can load it down to around 2200 fps or go all the way up to 2600 fps. That big fat case is much more impressive to look at than anything else smaller. What is wrong with a belted cartridge? I don't see anybody complaining about the 375 H&H. It sounds like a fashion excuse to me. With every said, I would not mind to have a DRG rifle chambered with a non-belted cartridge like the 450 Dakota/450 Rigby. Later guys. Ming

Ming,
On a slope shouldered cartridge like the H&H's the belt is a necessity for good head-spacing. Weatherby used belted cases in the beginning of his cartridge development because they were the biggest he could find. Once the case has been blown out in the square-shouldered chamber, the belt becomes useless. However, in the magnum-obsessed '50's, if your development didn't have a belt, it wasn't a "magnum." None of Weatherby's belts are functional. Every cartridge of his has a lovely, sharp shoulder that allows for perfect head-spacing without any help from the belt. However, once Roy had built up his line of cosmetically belted cartridges, he couldn't abandon the belt. It was a marketing thing, you understand. Thus, when he decided to build the biggest and baddest cartridges around, he chose the .416 Rigby because it was big enough to be huge but not so big, like the .505 Gibbs, that he couldn't fit it safely in his actions. Now he had the proper case capacity to send a heavy bullet at phenomenal velocities but to keep his fans happy, he had to belt them. The practical result is that he ended up with a 2 round magazine. My preference for a 4+1 capacity is my reason for going with the Rigby design. Yes, I agree, you can load the big .460 down to perfectly sensible levels and have a serious, useable dgr. I'd just rather not have the belt in the way of those extra rounds.

Sarge

Ming- The only thing I have against the .460 Weatherby is the size of the cartridge which results in limited magazine capacity ( read two), their Cheezy magazine and their extractor system. Yes, I own one also! You can load one down to 2400fps but you still only have one in the pipe and two in the box. In comparison, I can get four or five in my 450 Ackley, mod 70 Winchester. A major reason I like it so much.
When you hunt Buff it often takes three shots and I just hate that dry feeling! Reloading once you've run dry gives me that queezy feeling. I've looked into it and there is no good solution to the mag box problem in 460 WBY rifles that I'm aware of. Even Ted Blackburn can't get it to work.
Now you could convert a Ruger 416 to 460WBY and get one more round in the box, I've thought about that before and still like that idea. I'd still load no more than 2400fps.-Rob

[This message has been edited by Robgunbuilder (edited 03-04-2002).]

I have a dummy 450 AHR round which Ed Plummer of AHR mentioned was the same as the 450 Rigby. This brass was available from AHR for $2.25 a piece...but it is made by Bertram and it appears to be the soft stuff. Nice round though! I think there were some proprietary issues wrt using the 450 Rigby "name" and this gets around it I believe??? Jeff P

thank you all. I think it have zoomd into the rigby or dakota. I have the solo safari book but i am going to read it over again.I don`t like to have somthing that everybody have. something ekslusive is fun. the win mag is to usual, the wby are just powerfull. the rigby sound good. I do realy don`t need this gun. I have a shultz & larsen in 9,3-62 an that is enough for the norwegian moose. The 450 are just for fun. have fun!!

Thanks Rob and Sarge for your insight. I learn something everytime I post something. Good shooting guys. Cheers! Ming

S&L,

I would like to put my oar in this pool too. I got interested in .450' bore size rifles in about 1996, and I did a lot of research and some interviews with various people, including Art Alphin from A-Square and David Lyttle from KYNAMCO.

I ended up having A-Square build a .450 Ackley Magnum, but I was never happy with the way that rifle handled. I think I was mentally comparing it to a Rigby rifle that I handled in .450 Rigby Rimless -- that rifle fit me.

There are slight differences between the Dakota, the Rigby case and the Weatherby besides the belt. Art Alphin did the design work on the Dakota line of cartridges, and he told me that the .450 Dakota is based on the A-Square Excalibur case.

A little English bird has told me that the .465 H&H will use the Weatherby case *with* the belt -- which H&H sees as their "brand" recognition. I expect to see and handle one at the SCI Convention in Las Vegas later this month. Also the .400 H&H.

For ballistics the 500 grain bullet between 2,150 and 2,350 muzzle velocity gave the most penetration in Mike LaGrange's testing (sponsored by the Zim gov't when he worked for them). Going up in velocity actually reduced penetration. The .450 Rigby is quoted as a 480 grain bullet at 2,368 fps, any more velocity is too much of a good thing.

jim dodd

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"if you are to busy to
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