To convert a cz 550 in 458 win mag to 460 weatherby mag what needs to be done? How much should it cost to do ?
Regards.
hjl

New Barrel, chamber to .460 wby, open boltface, scallop rear receiver bridge, alter mag box ( assuming it allready is a .375 box-if not new box), new folllower, second recoil lug and reinforce the stock. Then make it feed! Don't know OZ prices, but probably $1500 US.-Rob

1.) Open and deepen bolt face
2.) Ream chamber and head space
3.) Work out any feeding issues (my guess is they won't exist since CZ uses, I believe only one magazine box and follower in the Magnums).

quote:

Originally posted by ScottS:
1.) Open and deepen bolt face
2.) Ream chamber and head space
3.) Work out any feeding issues (my guess is they won't exist since CZ uses, I believe only one magazine box and follower in the Magnums).

Scott,
you know Rob has actually DONE this type of work, himself, right?

cz has 2 magboxes, one ribbed for HH cases, one not.

jeffe

I have had 2 rifles in .458 Lapua built by the methods outlined by both Rob and Scott.

The one done with a McGowen barrel was kept.

The one done as a straight rechamber of .458 WinMag to .458 Lapua was subsequently rebarreled with a Lilja barrel in .375 Laoua.

You can do it either way and get satisfactory results. I did.

There would be little difference between converting a .458 WinMag CZ 550 Magnum to either 460 Wby or .458 Lapua.

Just curious, why a new barrel?

The CZ 550 Magnum barrel in .458 WinMag is about 0.670" at the 25" muzzle, and has a 1:14" twist.

It will do a satisfactory job when rechambered to 460 Wby. The chamber portion of the barrel is quite beefy and has an integral island for the express sight, some good points to recommend it.

Indeed, the SIGARMS M98 Magnum Mauser ("Mauser Banner Rifle") is also only .670" at the 25" muzzle in the 450 Dakota chambering.

You will have a choice in twist, contour, and a fresh start on concentricity of chamber and trueness of threads if you start with a new barrel.

You can get an acceptable shooter if the .458 WinMag was a good shooter before the rechamber to 460 Wby.

You ever run a unsupported .460 wby reamer into a .458 win chamber? It doesn't run true till the pilot engages the throat. The resulting chamber will be non-concentric to an unpredictable result. It may not matter to most but it does to me!, I don't do that kind of work! Buy a fresh barrel and do the job right.
Jeffe is correct- you need to power file the ribs out of the .375 box before the cartridges will stack properly. The rails also need a little file work and the ramp needs to be reshaped a bit to feed smoothly. -Rob

I had my CZ 550 .458 Lott converted to .460 Weatherby. It wasn't too much work to get it to go. Make sure you reinforce the stock. Also, if the .458 recoil in any way bothers you, I would maybe rethink this conversion. The Weatherby recoils a lot more at full power than the heavy Win Mag or Lott loads, factory or reloads.

quote:

It doesn't run true till the pilot engages the throat. The resulting chamber will be non-concentric to an unpredictable result.

Rob, just curious why this is different than just about any rechamber? When I rechambered from 30-06 to 308 Norma wasn't the reamer unsupported? Is it only the 460 or do you just prefer not to rechamber?

Like I said just curious.

I'd like to know his explanation was well, since reamers typically follow holes. The 458 Winnie chamber is basically the same as what one would get with a roughing chamber reamer, nothing more.