One of the first custom rifles
I built for my self was a 30/378 Weatherby (I still have it)
Weatherby Mark 5 action, blue printed.
Shilen 27.3" #7 taper, 1 in 10 twist, select match stainless, 11o crown.
Accurate innovation laminated stock.
Leupold LPS 3.5x14x52.
Most accurate load = 180 XBT with 120grs H 50 BMG @ 3360 ft/sec and a SD of 6 for
5 shots. group size was .091 (Less than 1/10th of an inch).
Hottest load had 126grs and showed very little signs of pressure but accuracy fell of to
I have not tried it with any other powder because I was satisfied with the 50 BMG.
With the new powders it could improve but I'm not sure I could.
It realy likes the 200 gr partitions and I have pushed them to 3300 ft/sec with no pressure
NOTE: This chamber has the SAMMI free bore and can Handel heaver loads without pressure.
Do Not use this load data if you are seating bullets close to or on the lands.
It is a great long range round and will out shoot most shooters with good bullets and loads.
I dont use a break on this rifle ether.
J E CUSTOM