I currently have a Weatherby Mark V Synthetic chambered in 338-378 WM.I was thinking of having it rebarreled and rechambered to 577 T-Rex?Can this be done?Is ammo expensive for this caliber considering I do not reload and would have to order ammo from A-square.Any info on this subject would be greatly appreciated.

[ 05-24-2003, 03:28: Message edited by: Angeldust ]

If you don't reload, don't even consider it. Even if you do reload, I would hesitate. The brass alone is $5 a pop, and darn near impossible to come by. I don't even know if the Mk V action is big enough for the T-rex. The action work to make a T-rex that feeds is extensive. I would expect to spend $500 on a chambered barrel, and $500-1000 on action work. You'll also need a decent stock, and a second recoil lug on the barrel, so figure another $500-1000.

The most practicle big bore conversion for your Wehterby is the 500 A-square, the 378 case necked up to a 50. I believe there are a few sources of loaded ammo, but would expect it to run at least $5 a round.

The only big bore shooters that don't reload are the type of folks for which money is not an object. The rest of us all re-load, just can't afford to feed the beasts w/o it.

I hate to see a wonderful .338-.378 changed into anything else. Paul, what do the numbers for buying a used CZ550 (or BRNO ZKK 602?) and turning it into a .500 A-Square look like? Or a Ruger #1? The small(?) premium for the used CZ 550 saves the .338-.378 to bark again another day, and it could be that the CZ 550 bolt face is better suited to wretchedly larger cartridges like .510-.505 Gibbs (see John Rick's current thread in wildcats), .585 Nyati (somewhat challenging for gunsmith and reloader?) and .600 Overkill (search for threads)?

Or maybe he should pick up one of those Montana 1999 PH actions with the .750" bolt and build from scratch?

There are some possibilities, and if you have money and are willing to pick up some handloading skills, you don't have to pick .577 T-Rex. It seems to me that somebody was mentioning just the other day that it is possible to mail-order .505 Gibbs ammunition that pushes a 600 grain bullet at 2500 fps?

Seems to me that the Wby. Mark V action is not a controlled round feed action?

In my opinion the counterbore of the Weatherby bolt is right at the limit with the 378 size case rim.

I think some 585 Nyatis are done with a rim rebated down to 378/416 Rigby size and the 585 Nyati will give you all the power you can handle and then some. If the the lips of the in line magazine were spread further apart then I think the magazine would probably feed 585 Nyatis OK.

Apart from barrel and chambering you would need another stock as the Wby Synthetic will not be big enough for a 585 barrel.

Instead of a second recoil lug on the barrel I have always preferred a metal strap or plate that has a slot at one end for the action recoil lug and the plate extends up into the forend and is epoxied in place. It is best to have the action recoil lug narrowed by about 3/16th" either side.

But overall I agree with Paul that the 500 A Square is the best way to go for a real big banger. But you will probably still need another stock for the bigger barrel.

You might also consider a 416 Weatherby as the standard Wby barrel contour for their 416 is the same as your 338/378. If you fire off a few 416 Wbys loaded to full power and without a muzzle brake I think you will find about all the recoil you want. In the Synthetic stock I don't think you will need a second recoil lug on the barrel.

Mike

Unless you reload, you simply can not have a reliable source of ammo... although...

I doubt, without a heavy gun and brake, that anyone would shoot a full box in 6 months...

I nearly built one... fortunatly, i've been shooting a friends 577 NE.... and at REAL 2050 loads, it's all I can do to shoot it and hit the paper... Instant flinch for the second barrel. You just can't imagine it.

If you are looking for advice, sell the 338/378, buy a cz in 416 rigby and rebarrel for the 500A/Wells/JAB, etc off the weatherby case. You should get pretty close on the swap.

I built mine as a 500 jeffery, but with a name like jeffe, you just can't have an a2 when the jeffery is right there.

With lead bullets and surplus powder, I am able to shoot at about 28� a round... less than the cost of the RL15 and dollar bullets.

Let's cover the costs of a 500 a2
cz550-- 650
rebarrel and blue 450
Sights 200
recoil lug 50
stock (you do it) 300 (pad too)
lead/merc to 10.5# $5
dies 150

so, for ~1800, you can have an a2, that will shoot harder than you can...

jeffe

The answer is NO! A Weatherby bolt won't have enough metal left on it to control the .688 rim of the T-Rex. Failure to feed and failure to extract would be the norm.
If you want a T-Rex your options are a much modified1917 Enfield, A Bauska BBK-02, Granite Mountain, praprie Gunworks or Montanna Rifleman PH action ( when it becomes available. Brass as others have said is availablke only from Horneber unless A-squared gets back in production.
With A weatherby your best bet as others have said is the 500 A-2 its a formidable round and easy to build on a CZ550. It is probably all the gun you can handle anyway!-Rob

Angeldust,
Not a lot I can add to the above suggestions.

Except for loading a Nyati- I think DKT inc sells cartridges.

Once you have whatever calibre you will find people to help you(or even do it for you for a fee!)There are small businesses here that reload customers brass for them. I assume the US would have the same.

Its no big deal. The ammo will flow.

PM me if you want some more ideas mate

Karl.

[ 05-24-2003, 07:17: Message edited by: Karl ]

jeffeosso
What type of 577 are you shooting, and how much does it weigh?