Rechambering a 458 Lott to 450 Rigby

[hammz]

So I just ordered a CZ 550 in 458 Lott and already want to rechamber it to 450 Rigby. What would be needed to do this? The action is already a magnum length action so we're good there. Theoretically it should just need the chamber reamed for the 450 Rigby.

From what I understand the .458 Lott uses the .375 bolt face, so it'd also need the larger Rigby bolt face added, correct?

 

[bruce moulds]

the question in the room is why?
bruce.

 

[krish]

I am looking to convert mine too for a while. Why............ because I want to. There is no reson we buy different guns while one gun can do it all MOSTLY. Still we buy several. This hobby is such.

 

[krish]

PTG have reamers available. The bolt face need to be opened up. The feed rails need work aswell. A good gunsmith should be able to advice. I am debating to convert ruger rsm 458 or cz 550. Rsm look like the magazine need work too. One of the reson I wnt to convert is I have sevr as l of both.and I bought large quantity of 500gr bullets for a good price. I like the 1 in 14 twist comparing to 1 in 16.5 twist for longer heavier bullets for stabilization.

 

[John P.]

A bit sideways post, but the 450 Dakota is almost the same as the 450 Rigby. Years ago I got the urge to build a rifle similar to the then newly introduced 450 Rigby and settled on the 450 Dakota due to brass availability.

Got as far as chambering and fitting the barrel, putting on a barrel recoil lug and sourcing the front ramp and barrel band swivel.

Action is the CZ550.

Here it is, on the 450 Rigby article:

Action is new, out of the box, bought it from Brownells years ago.

Another photo:

Shown with the PTG chamber reamer (pilot bushing type) and headspace gauge.

Barrel, action, chamber reamer and other parts were sourced way back in time, prior to the PTG problems and prior to the Pac Nor fire.

Barrel is a No. 6 Pac Nor. Intent was to build the rifle heavy, maybe 11 to 12 pounds depending on stock wood.

I have a box full of over 200 new brass for the rifle.

Sights and swivel band have not been silver soldered, still loose.

Might get around to completing on one day, might not.

If anyone wants this thing I may be talked out of it, depending on the Moon phase. If I decide to sell the combination I will post in classified.

 

[krish]

If I may ask what will you want for it.
Krish.

 

[baxterb]

Action length is one thing, feeding is another. The 450's shoulder is .090 larger in diameter and .057 larger at the base. Going from the Lott to the Rigby will require mag box/rail alterations to get it to Mauser's rule so it feeds as it should.

 

[rcarpenter]

I'm curious, what is the cost of opening up the bolt and doing the feeding work on a conversion like this? I'm wanting to do something similar and haven't really found what to expect.

 

[hammz]

I'm curious, what is the cost of opening up the bolt and doing the feeding work on a conversion like this? I'm wanting to do something similar and haven't really found what to expect.

Kind of late replying, but at least with a Ruger No. 1 I had one rechambered from 458 Win Mag to 458 Lott a while back. Cost was $125 total. With the opening of the bolt face needed I'd guess something like $200-250 or so?

 

[baxterb]

As i mentioned above, there is a LOT more to this than rechamber and bolt face. To do it right, the magazine box needs work,, which means the underside of the action will need to be machined to match the new magazine profile, that will probably cause some small work on the feed ramp, the rails will need to be opened and re-profiled, and all of it properly polished together and tweaked until it's perfect. The extractor will also need to be re-shaped for the larger rim. You'll also need a new follower and likely spring. on a DG rifle, there's only one way to do it right - just send off the rifle, hold your nose and pay what the reputable smith says he's worth.