Trying to make decisions Building a 338-378 Weatherby

[NorthernWeatherby]

I am building a 338-378 Weatherby Magnum. I am starting with a Nesika round action, I have no experience with Nesika, but have chosen them for a few reasons(if anyone has a thought on this let me know.) I am going to go with a 28 -30" fluted barrel with a 1 in 10 gain twist. I currently have a .300WBY Mag. with a 1 in 10 gain twist with a 28" fluted barrel 1.25" to .8" taper and it shoots very well, I have not pushed it past 500m. I am building the .338 to cover 500m to 1200m.

Can anyone give me advice on these choices. I have been shooting for the better part of 20 years and am accustomed to recoil, the rifle will be heavy and should not be to bad to shoot in the prone position.

NorthernWeatherby
Custom .300 Weatherby Magnum

[AJ Peacock]

Welcome to the site.

What bullet are you planning on shooting, Sierra MatchKing 300gr?

Should work well for that.

AJ

[Buffalobob]

Nesika was sold a few years ago and their quality control might not be what it once was. You might consider a different action.

[J E Custom]

Originally Posted by NorthernWeatherby

I am building a 338-378 Weatherby Magnum. I am starting with a Nesika round action, I have no experience with Nesika, but have chosen them for a few reasons(if anyone has a thought on this let me know.) I am going to go with a 28 -30" fluted barrel with a 1 in 10 gain twist. I currently have a .300WBY Mag. with a 1 in 10 gain twist with a 28" fluted barrel 1.25" to .8" taper and it shoots very well, I have not pushed it past 500m. I am building the .338 to cover 500m to 1200m.

Can anyone give me advice on these choices. I have been shooting for the better part of 20 years and am accustomed to recoil, the rifle will be heavy and should not be to bad to shoot in the prone position.

NorthernWeatherby
Custom .300 Weatherby Magnum

The 338/378 is an awesome round and should do everything you want it to.

I don't know much about the Nesika action but it should be OK.

As to the barrel, 28'' to 30'' will produce good ballistics. I would not flute the barrel
because you will need the weight unless you put a brake on it.

My best piece of advice is to have you or your smith hold the head space to less than
.001 (I set mine .0005 to .0001). solving the free bore issue.

And you should neck size only to improve brass life, even then don't expect more than
3 or 4 firings.

I would look at the 250gr accubond for hunting and the 300gr SMK for targets beyond
1500 yards.

Just my 2 cents.

J E CUSTOM

[NorthernWeatherby]

I am planning on the SMK 300grn, but as of yet am unsure of what I will use for hunting.........Any action suggestions other than Nesika?

[J E Custom]

Originally Posted by NorthernWeatherby

I am planning on the SMK 300grn, but as of yet am unsure of what I will use for hunting.........Any action suggestions other than Nesika?

How about a MK 5 action ? that's what they were built for.

J E CUSTOM

[NorthernWeatherby]

My .300WBY Mag. is based on a Japanese Mark V action, the only reason I am thinking of not going with a Mark V is the one I have now is starting to lose its smoothness. Becoming what feels to me as a little loose. I was thinking of something with tighter tolerances. Due to availabilty it would be an easier action to go with for sure. Do you think that a tighter action is going to make that big of a difference? Worth the extra cost? If this rifle shoots well it is likely that I will not build another one. I still have the same Model 60 Cooey I had when I was 10 years old, it shoots like nothing else and I will never replace it for that reason.