custom build on .378 bee mk V action

[scoop]

I've got a potential .378 weatherby action that i am interested in buying to build a custom rifle from. Im fairely new too rifle building and limited on building on a mk V actions. From what i understand is that there are 2 sizes of action (9 lug mangnum and 6 lug standard). So this .378 action length would be good for all weatherby magnum calibers or just .300 and up?? That being said the bolt face would need modification?, proper mag box? and anything else action wise?

 Ideally i would like to build a .257 bee, 270 bee or 7mm bee. Thanks

[Chris338378]

You are right to make a magnum caliber you want the 9 lug bolt.  The first problem you're going to have is the bolt face on a .378 is bigger than that of a .275 so you'd have to close it up which I have never tried to do.  It is far easier to open a bolt face to make it bigger but that can only be done within reason.   I know it's an extreme example but you can't open the bolt face on say a .223 so it would accept a .270.  Another problem you have is a .378 is much longer than a .257 so to make the magazine box to work you'd have to but a stud in the front of the box to make it feed properly.

The simplest thing I can suggest is to find an old Weatherby that is in rough shape in a .300 Weatherby (since it is the most popular caliber) and use that for your build.  I wouldn't worry about the barrel or finish on the action as long as it doesn't have heavy rust since you'll end up rebluing it and will be using a new barrel.  For the extra you'll spend this way it'll wash out in the money you'll spend on machine work and trying to make the bigger .378 action work for what you want to build. 

[scoop]

Ok i did some more digging and i was wrong. The fellow says it was originally a .30-06. It is a 9 lug german action. His intentions were to convert it to a .416 but it never happened. Some of the parts are off a .378 (mag box, follower etc). Price is decent. I dont know how difficult it would to be to find another bolt for the caliber i want, is it as simple as ordering one from weathebry? My biggest concern is that the receiver would work with what caliber id like to build. Are all the 9 lug receivers interchangable between all the weatherby magnum calibers? This action kind of fell into my lap and id like to take advantage of it if its worth it. My dilemma is that i want a LH action, this is and i live in Canada (action is also in Canada).

[Chris338378]

There is something MAJORLY WRONG here.  First a 30-06 would have six lugs not nine.  Secondly a .378 requires a longer action than a .30-06 so I have no idea why there would be .378 parts in it or how he would even know unless he changed them out himself.  It sounds like someone was already messing with this gun to me.  If you have the serial number I'd call Weatherby and ask them to look up what caliber it was when it was made and confirm with him that it actually has nine lugs.  The nine lug action is for the magnum calibers while the six lug action is for non-magnum calibers.

[WA Mtnhunter]

The German and early Howa actions were 9 lug.  The 6 lug came along when Weatherby shifted production to the U.S. and built the lighter standard action.  Bolt fact is larger for the .378 than the .375 Wby or .300 Wby.

[scoop]

It started life as a left hand german mk V .30-06, 9 lug. It was then hobbled into a .416 and never completely finished. All I want really is the receiver, and bottom metal. Will it work to build a .257 or 270 bee? How hard will it be to find a LH bolt for the same caliber and mag box, and follower? I have had a hard time finding LEFT HAND weatherby stuff. If this will work i think its worth the $200.

[257 Shooter]

Once the bolt face is opened up that is pretty much what you're going to have. If it is now machined for the 378 Weatherby case head, it will have to be a 30-378,338-378, 378, 416 or 460. That's not all bad. The receiver itself can be made to work for any of the magnums. The standard length magnums have a block in the rear of the magazine box and a shorter follower. It's just that once there is machining done you really can't go back to something smaller.

It is very difficult to just get a bolt but I'm sure one can be found in time. Weatherby may replace it but I don't think they will sell just the bolt. Good luck.

[scoop]

$450 and weatherby will build a bolt for the receiver. And sounds like its easy enough to get the mag box and follower.

[Marishka]

Instead of buying the .378 action perhaos you should look a a used Mk V. The .257s listed are pricey but the .270s are reasonable. Here is a link  http://www.gunbroker.com/Bolt-Action-Rifles/BI.aspx?Keywords=weatherby+v+270&PageSize=75

[HuskyMusky]

I'd build it into a .416 Rigby and call it a day!

or perhaps a .338 Lapua, 30-378wby, or even a 300/338RUM/edge?

[scoop]

Im LH eyed so finding a left hand Mk V for a good price to use the parts, so far hasnt worked. Im pretty well covered for large caliber weatherbys.

[Marishka]

Here is a link for a LH German .300 Weatherby that might interest you. It is equipped with an Accubrake and, like all of the other German .300s I've seen, it probably has a 12:1 twist. http://www.gunbroker.com/Auction/ViewItem.aspx?Item=323927450

[Marishka]

Look at there


http://www.gunsinternational.com/Weatherby-Mark-V-Deluxe-Left-Hand-300-Wthby-Magnum-24-.cfm?gun_id=100267454

http://www.gunsinternational.com/Weatherby-Mark-V-300-Wby-Mag-Left-Hand-Rifle.cfm?gun_id=100241320

[Marishka]

One more

http://www.gunsamerica.com/989284050/Weatherby_Mark_V_270WbyMag.htm

[scoop]

Thank you for the links  Im Canadian.... by the time i pay someone the importing fees theres no point the price skyrockets.