Previously posted on the Gunsmithing Forum

A good friend and hunting partner just purchased a ZKK602 in 458 Win Mag. He's toying with the idea of opening it up to the Lott cartridge. The magazine is long enough as it comes but He's curious to know if anyone has done this, and what pitfalls may await him. Questions have been:

Who to have do the work?
Will there be more involved than just reaming the chamber deeper?
Are feed rails and ramp likely to need modicfication?
Any other comments?

I answered you in gunsmithing. was there something defective in my post there?
it is a simple rechamber and MAYBE touch up the feeding

Nothing defective, no foul intended.

Pretty new to this and was just was hoping to hear a few responses to the specific questions I asked. Thank you for your second response it told me volumes more than "its a 2 hour job, at the most... and darn easy"

sorry, i guess we both assumed things..

there is a "conversion" reamer, which does not cut the belt, making life easier. it has the same headspace, and the 602 is a pretty easy one to get to feed properly.. internally, it is the same as the cz550 magnum, and it should be a quicky..

it's not run a reamer and go, but not far form it
jeffe

Thank you - I was unaware of a conversion reamer. I was curious how one would cut the longer chamber to a greater depth without affecting headspace.

The .458 head spaces on the belt the same with the Lott. You can use a standard Lott reamer just run it in till it just touches the cut for the belt. I would use some machinist blue to show when it touches.
Bill

I don't see why everyone doesn't do just that, then if recoil is a problem then load the lott down to about 2200 FPS and have a nice mild load without the pressure, but its not straining to get up there where it needs to be like the 458 Win. It just makes since to me.

Will the reamer follow EXACTLY the existing chamber, or is there a risk of a little "dent" at the end of the old chamber?

There is always a chance that a given reamer might not clean up a particular chamber. All that being said, the lott was designed to clean up specifically the 458 Win. Mag. chamber without leaving a step. The results on your rifle may be different.

When CZ first came out with the 458 LOTT They just re reamed the chambers ,,X ed out the Win and stamped with a letter punch LOTT under the win.....Thats how mine arrived from the factory .....

does your 602 have the pop up peep.?