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.338-.378 Weatherby Bullet Seating Depth

.338-.378 Weatherby Bullet Seating Depth
« on: November 23, 2019, 03:24:10 PM »
Good day fellow Weatherby Reloaders,

I recently upgraded to a .338-.378 Weatherby Magnum Mark V. What i am struggling with is the Bullet Seating depth. I commonly would use a Modified case Gauge to see where to start backing off from, but i can see they make on for this caliber. I could modify my owe casing?

I have read a lot online about this Caliber/Weatherby Magnums like the bullet to be seated deeper or farther from the Lands than normal?

Any comments on Seating depth would be greatly appreciated. I am waiting on all my pieces to arrive to start reloading, at about $6-$7 per round re-loaded, would be great to have a starting point.

Thank you in Advance.
.338-378 Weatherby Mark V Accumark
4-16x50mm Ziess Conquest V4
7mm Weatherby Magnum Weathermark LT Custom
TBD - open to suggestions

BB340

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Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #1 on: November 23, 2019, 03:27:44 PM »
Well I think most of us start with just max magazine length. Due to the free bore it is highly unlikely you will be able to seat your projectiles out far enough to touch the lands and still be able to fit the loaded round in the magazine.
Aussie gun nut.

Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #2 on: November 23, 2019, 04:10:35 PM »
Well I think most of us start with just max magazine length. Due to the free bore it is highly unlikely you will be able to seat your projectiles out far enough to touch the lands and still be able to fit the loaded round in the magazine.

Thank you Kindly for the comments, I will use that in my Test Loads.
.338-378 Weatherby Mark V Accumark
4-16x50mm Ziess Conquest V4
7mm Weatherby Magnum Weathermark LT Custom
TBD - open to suggestions

257 Shooter

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Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #3 on: December 04, 2019, 05:12:51 PM »
You could make your own modified case if you have access to a lathe. Its a 1/8 pipe tap. We made one for mine when the rifle was built.

 Like already mentioned, you cant likely get to the lands and feed as a repeater. My rifle was built as a single shot. Loaded cartridges with 300 grain Sierra match bullets are over 4. This is a custom chamber though.

Good luck.

Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #4 on: December 04, 2019, 11:12:11 PM »
You could make your own modified case if you have access to a lathe. Its a 1/8 pipe tap. We made one for mine when the rifle was built.

 Like already mentioned, you cant likely get to the lands and feed as a repeater. My rifle was built as a single shot. Loaded cartridges with 300 grain Sierra match bullets are over 4. This is a custom chamber though.

Good luck.

Thank you for the Comments...I actually contacted Hornady and they gave me the thread size to make myself.

From what i am ready, my loads will be know where near the Lands. Waiting on the Brass to arrive and will get at it.

Thanks again.
.338-378 Weatherby Mark V Accumark
4-16x50mm Ziess Conquest V4
7mm Weatherby Magnum Weathermark LT Custom
TBD - open to suggestions

Weatherby4Me

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Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #5 on: December 26, 2019, 05:42:10 PM »
I just want to reply and say I'm jealous. You have my dream caliber! That is one high dose of Elk medicine!
Real men use belts, boys go beltless.

Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #6 on: January 15, 2020, 02:51:51 PM »
I dont use mine for hunting so single feeding is how I do buisness. I started my coal off at 4 and just tuned depths.h

Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #7 on: January 15, 2020, 03:36:00 PM »
When I was stuck like you are I took my calipers into the gun shop and asked if I could measure a loaded round, that was my starting point.
Doug

.257

Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #8 on: January 15, 2020, 05:20:06 PM »
Looking at different load data

Barnes 3.720
Nosler depending on bullet weight and type
           3.700-3.750
Hodgdon depending on bullet weight and type
            3.640-3.900

Re: .338-.378 Weatherby Bullet Seating Depth
« Reply #9 on: February 08, 2020, 03:02:15 PM »
I just want to reply and say I'm jealous. You have my dream caliber! That is one high dose of Elk medicine!

Thank you....It has been a long Time and I finally was able to purchase the Rifle I have always wanted...

It is a bit of a Price jump reloading, I went from $45.00/Box to $130.00/Box.

Appreciate all the comments.
.338-378 Weatherby Mark V Accumark
4-16x50mm Ziess Conquest V4
7mm Weatherby Magnum Weathermark LT Custom
TBD - open to suggestions