CZ550 375H&H to 458 Lott started today

[Woodcarver]

Dropped a CZ550 in 375H&H off at Kevin Weaver's (Weaver Rifles) this afternoon. Having it rebarreled/rechambered to 458 Lott. It's a Safari Classics that currently weighs just over 10# nekkid, and 11.3# with Leupold VX-6i 1-6x24 on it. Should end up close to the same when it's finished. NECG banded front sight, 2 leaf rear, barrel band swivel, 24" finished length on a Douglas barrel.
He tested some dummy rounds in the mag and was pleased with how they lifted. Need to machine a bit on the left side to ease the feed from that side, but thinks that should be all it takes. Polish the action a bit and blue the barrel to match the existing receiver. He thinks I should have it back by Christmas unless the barrel takes longer than expected to get. A new set of dies and a couple hundred pieces of brass are waiting when it does get returned.
Starting the design phase of modifying the appearance of the stock to better suit me. Kicking around ideas of the myriad types of wood that might become a new tip and grip cap, and other ways to take a relatively plain piece of walnut and make it not plain, but probably won't get started on that immediately. Looking forward to playing with another new caliber and another chunk of wood.

 

[Frederik]

I love my CZ550 Lott with the added long magazine space I load all my rounds extra long and seat the bullets further out if they can do it.
Both my solids and softs now has driving bands allowing me to do it.
The ammo doesnt have much space to hit the magazine on recoil and it seems to feed easier when seated long.

My rounds now look like mini 500NE but with a rim.

 

[Luvthunt]

Good luck with your project. I am on my second Lott and this one is a Brno. Be sure your smith gives you a chamber long enough to take advantage of the mag length.
Originally in the first Lott I used IMR 4320 to get over 2200 fps. Now that 4320 is no more I found that Tac did what was wanted with no powder compression.However I only use lead core bullets (Swift and TBSledgehammers).

 

[Frederik]

For my reloads I use Norma203B depending on your case volume, barrel length mine is 25" and overall cartridge length 80gr should give you close to 2200fps. Don't worry if your case is above 100% filled with bullet seated I use droptube to pour in the powder it gives some extra space.

 

[Woodcarver]

Good luck with your project. I am on my second Lott and this one is a Brno. Be sure your smith gives you a chamber long enough to take advantage of the mag length.
Originally in the first Lott I used IMR 4320 to get over 2200 fps. Now that 4320 is no more I found that Tac did what was wanted with no powder compression.However I only use lead core bullets (Swift and TBSledgehammers).

I've read several places that 4320 was the powder to use with the Lott. Fortunately, some time back, I had picked up a keg of 4320. Can't remember what it was intended for as it is still unopened, but that appears to be fortuitous now that I have (almost) a caliber it should be good for. By any chance, do you have your load data for 4320 still?

 

[Luvthunt]

I will have to look up the data when I get home.Again I remind you my data would not be for mono metal bullets only lead core.

 

[Woodcarver]

Thanks. My plan also. I've never shot a mono-metal bullet in anything.

 

[Nhoro]

Maybe try strip down you stock and refinish it. My cz had some good wood under that plastic goop that cz spray on it.

 

[Frederik]

Had a quick look at IMR4320 with 500gr Swift, 75gr of powder should get you to 2200fps but will be compressed a bit.

 

[Woodcarver]

Maybe try strip down you stock and refinish it. My cz had some good wood under that plastic goop that cz spray on it.

That is definitely in the plan. Once he's done, I'll get rolling sometime this winter in giving the stock a facelift. There's been several times where I found a pretty decent piece of wood hiding under those factory finishes. They want the consistency of appearance so they hide the wood to achieve that.

 

[BeeMaa]

@Woodcarver - I’m looking forward to seeing the progress on this rifle.

After stripping down the wood, if it’s not up to the standards of the rest of the rifle, I’d recommend finding a proper blank and have it roughly inletted (or fully fitted with proper bedding if you prefer).

It would be a real shame to have all that work done on the metal and not have the same attention to detail given to the timber.

 

[Luvthunt]

WC
Did the mag article get thru?

 

[Woodcarver]

WC
Did the mag article get thru?

Yes. I was able to open it today (didn't get a chance yesterday). Appreciate it.

 

[Papabear55]

I have had luck with rl15 too

 

[colorado]

Kevin's an awesome gunsmith. Say Hi for me. He did the last mod on my CZ in 500 Jeffery to get it to feed perfectly.

Chuck

 

[CoElkHunter]

Kevin's an awesome gunsmith. Say Hi for me. He did the last mod on my CZ in 500 Jeffery to get it to feed perfectly.

Chuck

That's good to know he can work on CZs. I'll have to take my Lott to him and have him smooth out the feeding issues I'm having. He's only about 25 minutes from me.

 

[Woodcarver]

A little update. There was a pause in the build as nobody has a barrel band stud to fit the new barrel (.995 id), so I enlisted the services of my son, who is a machinist. Somebody in the shop had rendered the fixture he needed inoperable, so another was ordered; some time passed. Christmas was approaching; more time went by.
First go was using a PTO shaft of sufficient diameter. That didn't go so well (at least 1 broken bit) as I believe they are hardened; more time passed. He was able to get a piece of cold rolled rod a couple weeks ago and cut the new band. Picked it up this past weekend and delivered it to Kevin yesterday. Back on track.
Looking forward to seeing it finished.

 

[colorado]

Say hi to Kevin for me!

 

[NDWoods]

How did this turn out? I have a 550 375 H&H I am debating selling or having it rebarreled.

 

[Woodcarver]

Turned out well. Forgot to do an update to this thread apparently.
Before:

After:

You can see the 458 Lott barrel is a significantly heavier barrel, 24". Added just over 1# to the overall weight, putting it at 11lb 3oz. Very pleasant to shoot, even with full loads. Have not found any feeding issues, even with 500gr 67% meplat flat nosed bullets. Still working on loads as I will build a load from 350gr to 500gr.
Action is fully bedded with pillars. Barrel is free floated beyond bedding. Express site has 1 folding leaf in addition to the fixed; both need to be filed to whatever I decide is the final heavy load. So far, I've been shooting it with a DeltaPoint Pro red dot or a Leupold VX-R 1-6x24.
I haven't had time to do any of the stock modifications I am wanting to do, such as removing the front stud, moving the buttstock stud, putting a forend tip & grip cap on, and carving a border on the checkering. Spare time seems to have evaporated....