7-378 Weatherby, Long Range 7mm

adam32

Well-Known Member
Joined
Nov 14, 2007
Messages
2,096
Location
Kookifornia
We have played with the 300 Norma imp and necked it up and down. It will produce about rum performance with about 10g less powder and a shorter oal. The Lapua imp will produce about 200 fsp over the rum depending on the reamer. Yet still a bit shorter oal than the rum. The Lapua imp is pretty tough to beat until you go to a Cheytac parent case. Whole diff world.
I like the RUM's over the Lapua/Norma stuff just because I don't keep a rifle the same for long so it gives more options when rebarrelling. The 7mm Lapua Imp (AM) is about the best N/A hunting cartridge ever built though.
 

vanders

Well-Known Member
Joined
Jul 15, 2007
Messages
132
The 338 excalibur will hold 130 grain of WC 872 and its ball powder. I'm pushing 245 grain bullets at 3400 fps in a 32 inch barrel.
 

yobuck

Well-Known Member
Joined
Aug 23, 2008
Messages
1,515
Location
east central fl. /n.c. pa.
G

Gotcha. I can attest to the softness of their brass. 6.5-300 loaded hot doesn’t keep primer pockets very well. But it will run 143ELDX 3450-3500. Maybe get two firings out of it.
You can run a 7x300 Wby with 162s at that speed also, and both the STW and Rum as well. Which again, is why the 6.5x300 Wby died years ago for long range hunting.
And a 30x378 with 200 gr bullets at 3500 with a 36” barrel.
Maybe even less barrel with some of the newer powder.
BUT, velocity is one thing, and shooting them at distance is yet another, especially if your into hitting the thing your shooting at.
 

ctw

Well-Known Member
Joined
Mar 23, 2015
Messages
84
It has been a rumor for the past few months that weatherby was working on a 7-.378 weatherby mag. But then they came out with the 6.5 rpm. This was the chatter on weatherby nation; until I see it I will just take it as that, a rumor. ctw
 

lgloutfitters

Well-Known Member
Joined
Jun 9, 2018
Messages
67
Location
Gonzales County, TX
Thanks everyone for all the info and insight. But, y’all have made my decision tougher lol.

Let me clarify a few things that I didn’t post originally. I would like to build the most ballistically superior 7MM cartridge for long range hunting. one that will Get superior ballistics out of a shorter barrel. 24-26”. I want a good Light weight/maneuverable packing rifle. I run all bartlein and kreiger, was maybe considering carbon fiber, but I feel like I’ll lose my man card. But barrel choice is a whole other argument.

so, with that said. What is the most ballistic superior 7MM that can shoot/group well at long range, with the rifle being built for hunting? I don’t give two damns about barrel life, recoil, amount of powder etc. This rifle will be designed to hunt and kill, it stays in the safe when not hunting and it won’t be plinking steel.
 

vanders

Well-Known Member
Joined
Jul 15, 2007
Messages
132
I would stay away from the Wildcats and just go with the 28 nosler.
 

yobuck

Well-Known Member
Joined
Aug 23, 2008
Messages
1,515
Location
east central fl. /n.c. pa.
Thanks everyone for all the info and insight. But, y’all have made my decision tougher lol.

Let me clarify a few things that I didn’t post originally. I would like to build the most ballistically superior 7MM cartridge for long range hunting. one that will Get superior ballistics out of a shorter barrel. 24-26”. I want a good Light weight/maneuverable packing rifle. I run all bartlein and kreiger, was maybe considering carbon fiber, but I feel like I’ll lose my man card. But barrel choice is a whole other argument.

so, with that said. What is the most ballistic superior 7MM that can shoot/group well at long range, with the rifle being built for hunting? I don’t give two damns about barrel life, recoil, amount of powder etc. This rifle will be designed to hunt and kill, it stays in the safe when not hunting and it won’t be plinking steel.
The decision isn’t actually tough.
Because there much of any to be made based on your requirements.
 

ctw

Well-Known Member
Joined
Mar 23, 2015
Messages
84
I think a 7-378 would make for an exciting cartridge. Weatherby markv action 26" barrel and what ever scope choice you decide on. Powder capacity is there, go with a fast twist to stabilize the heavier higher ballistic bullets. I would try the Hornady .30-378 brass, a lot harder than weatherby or norma. I switched to Hornady and could not be happier for my .30-378 weath. mag. ctw
 

adam32

Well-Known Member
Joined
Nov 14, 2007
Messages
2,096
Location
Kookifornia
I wouldn't run anything with over 100gr capacity on anything shorter than a 28" barrel...a 24" and you'll be burning powder out the muzzle.
 

ctw

Well-Known Member
Joined
Mar 23, 2015
Messages
84
Don't be to concerned about poor or incomplete powder burn. The radius shoulder on the weatherby cases with it's venturi effect where designed to be a more efficient use of the gasses to propel the bullet. Giving that design a more complete or better burn on the fuel provided; or in this case powder. Now let the debate and theories begin. lol ctw
 
Top