I just received a 550 in .375. I can put 3 378 rounds in the mag and they cycle out just like my mod 70s. Just bump it forward and inch or so and the extractor picks it up enough to eject it. I remember someone else metioning that they had one in 378. Just wondering how much if any work was required it get it to feed.

I've got one now. Very easy rechamber of the .375 H&H to 378 Wby in the CZ 550 Magnum.

I also had an old BRNO ZKK 602 with a 22" barrel that I had rechambered to 378 Wby. That was too short, so it got rebarreled to 500A2(.510JAB).

The 25" CZ barrel is a good one for this, and mine is sub MOA for 3 shots and 2911 fps with 300 grainers, in my favored load. Feeding is an easy trick as you are seeing. Just open up the bolt face, rechamber and polish the rails and ramp until it is slick.

I still have mine in the hogback Lux stock but have added two extra crossbolts besides the factory one in the wrist. Crossbolt it fore and aft of the magazine, and no worries.

Thanks for the reply RIP. I thought it looked like it would go fairly easily. Don't know if I will go that route but these guns are so huge it seems like a waste to put those dinky little H&H rounds in there.

MTM,

what RIP said!

Rich
DRSS

I have thought about rechambering my CZ 550 .375 H&H to .375 Weatherby Magnum, seems like a good trade off of improved performance and economy. I like the fact I could use .375 H&H in a pinch as well. I haven't gotten around to doing this yet, maybe someday when I widdle down some of my other projects!

Got one of those too: .375 Weatherby is excellent.

Easily holds 5 down in the box, and feeds well. Has 3.8" box length, and with the .3700" long parallel-sided freebore of the latest .375 Wby chamber (2001), you can long-nose load them and get 2800 fps with 300-grainers from the CZ 25" barrel.

Of course you can slow them down if you want to.