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Cz550 rechambering ?

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23 June 2003, 07:16
Tongo
Cz550 rechambering ?
I have a CZ550 in .375 H&H. I would like to rechamber to .375 Rem. Ultra Mag. Is it possible?

Thanks
23 June 2003, 08:04
jeffeosso
1: YESS
2: Why?

Jeffe
23 June 2003, 08:52
N E 450 No2
Tongo
If you just have to have a litle more velocity you could "improve" the 375 or rechamber to 375 Weatherby.

But like Jeffeosso... WHY?
23 June 2003, 09:41
JudgeG
I went and shot my CZ .375 H&H yesterday with PMC 300 grain Barnes X's. (I bought 3 boxes for $20 each. Beat that!) (I posted pictures a month or so ago of the re-shaped stock, re-blue, etc. under the thread JudgeG's New Toy.) CLICK HERE

The rifle has no appreciable recoil, is extremely accurate, utterly dependable, holds 5 down and one in the chamber.

Like other posters, I can't figure why I would need more velocity, and if I did, there are always 270 grain bullets... but that's just MHO.

I like what one poster states in his signature, "One planet, one rifle." So I'm selling all my other ones.... NOT!!! But the .375 H&H can hardly be "improved".

[ 06-23-2003, 00:50: Message edited by: JudgeG ]
23 June 2003, 11:41
Mingbogo
Not sure about the dimensions of the 375 ultramag but it sounds like it is a little bigger than the H&H so it should be relatively easy to rechamber.

If you are gonna do a rechambering job, then why not rechamber it all the way to the 378 Weatherby and then load it up and down accordingly? [Smile]

Have fun deciding!
23 June 2003, 12:25
retreever
Tongo,

The only comment is that to much velocity in a DG rifle is not what you want...For you want to grind him down by absorbing all of the energy from the bullet...but if you are just looking for velocity then a RUM or 378 is the way to go...Or drop to a smaller diameter...
How much velocity do you want???

Mike

Freedom is not Free
23 June 2003, 13:01
PC
I agree if you want more than a .375 go staright to the .378 Weatherby why buggarise around with a couple hundred fps.

At the same token I have found the .375 H&H to be flat shooting enough and recoil is pleasant and they also kill very well. I am overall pretty wrapt with my cz .375 so much so that I wish I could afford a second one [Wink]
24 June 2003, 02:21
Philip
As everybody seems to wonder... Why???

The .375 H&H is an excellent round as it is.

Energy doesn't kill, holes do. Ever seen what happen when you put a "just-in-case" shot on a presumably dead critter? Just a slight shudder, almost nothing. That's all what wonderful energy (on paper) can do.

Got 3 CZ at the moment. The one I rechambered was from .375 to .458 Lott (changed the barrel, that was at the time they did not have a .458). But my good ol' .375 never felt like it needed anything more.

Put a long deep hole at the proper place, and you won't ever have a critter suing you for using a non-extra-plus-hyper-Magnum...

Good hunt!
24 June 2003, 05:22
Tongo
Thanks for the advice.

I have two .375 H&H rifles and rechambering one to .375 RUM would be a just because project.

I agree .375 H&H is just fine as is.
24 June 2003, 18:27
Robgunbuilder
It should not be a problem at all to rechamber to a .375 RUM. assuming the twist is the same for the RUM and the .375 H&H it should stabilize the faster bullets. All it should take is some rail work and ramp polishing. I didn't look at the dimensions, but if memory serves the chamber should clean up completely. Make sure the work is done by someone with a good machining background and proper equipment as the reamer will be unsupported initially and you don't want an egg-shaped chamber. Talk to John Ricks! I would not reccomend a .378 WBY to be made from a CZ550 in .375, because you will need to have the boltface opened,the extractor modified as well as the mag box,Ramp and rails extensively modified. A .416 Rigby CZ550 action is a better choice for that one.-Rob
25 June 2003, 07:43
RIP
I have both a .375 RUM and a 378 Weatherby that were made from CZ 550 .375 H&H actions.

The 378 Weatherby has the original CZ factory barrel rechambered from .375 H&H, 25" long.

The 375 RUM has a Winchester M70 Super Express barrel cut off one inch and rethreaded and chambered. 23" long.

With enough work you can get them to feed.

I am currently having a 45 Lapua done on a CZ 550 action that started out as a .416 Rigby. It feeds the 45 Lapua great from the get go. [Big Grin]
25 June 2003, 14:42
RIP
BTW, Rob is right about the .375 RUM cleaning up a .375 H&H chamber, assuming the original .375 H&H chamber is good, as they always have been in my experience with CZ. A straight rechamber to .375 RUM should be fine, but only if you have at least one other good .375 H&H on hand to leave unaltered. Everybody ought to keep a pair of black shoes on hand.