I am at the point for load work in a rifle I am building and would like some help if anyone has any load data. It is a 375-06 a.i. And I plan to shoot both 300 grain Hornadys and some 348 grain cast bullets. Anyone have any suggestions?

The July-August 1991 issue of Handloader had an article on the 375-06 imp. The 300 Hornadys were loaded with IMR-4895 57-59 grns. 59 listed as max.
IMR-4320 59-60grns with the 60 listed as max.
Velocities shown were from a 20 inch barrel, low of 2409 and a high of 2472. The accuracy figures for his rifle were moa or better with those loads. My gun has a 24" barrel and I duplicate those velocities very well with Viht N-540. The max loads that I chro'd were putting 300gr Barnes originals between 2484 and 2502. Unfortunately I don't have current access to the Viht loads right now. WW-748 can be used as well. You might consider 35 Whelen loads as a starting place. The cast loads in the article showed a 271 Lyman with IMR-3031 and 40gr at 1787fps with accuracy of 3/8" at 50 yds. You might consider a 250gr Kodiak bonded. You should be able to see 2600+fps with it.

I don't have the capacity of the 375-06 AI but loadtech shows the 35WhleneAI and 358 Hawk are l;ess than a gr apart. So 375 Hawk data should be close. Start low and work up.
www.z-hat.com

Thanks for the advice guys, I sure do appreciate it a lot. Will see if I can find that issue of hand loader online. I got a 346 grain mould from NEI and plan to use that mostly with this rifle. The Idea of building this one is because of the high cost of bullets I wanted something I could shoot cast bullets with. I expect to have it stocked in another month but all the metal work is complete except for the final finish and I will use another stock this coming week to start load work. Formed 83 old mil surp. Cases , had to anneal twice, for it and loaded a few with IMR-3031 so far. I will also order Fred Zegglins wildcat book and see what he offer in advice. I am hoping to get 2000 fps out of it with mild pressures but not sure how it will shake out. Thanks again for all the advice.

My 375 Scovill likes 59 grains of H4895 under a 250 gr Gameking @2700 fps with a SD=6 if I remember right.

Good luck

Well I finally got the time to do some load work and was pleasantly surprised. Shot this four shot group with 300 grain Hornady Bonded round nose bullets behind 62 grains of IMR-4350. The only velocity I was able to get was one at 2331 f.p.s. due to having fifty seven days of rain so far this month and no sunshine for the crony. The rifle is still in its factory stock and zero attempt has been made to properly bed it.
I will have it stocked in a nice Turkish walnut in another month or so and can really get down to business with it but if I can keep 1 ½†groups with it I will be more than happy. Have everything I need to cast those nice long 3/8†pills so I will be doing that and hopefully have a cast load worked up shortly as well. I will probably cut back to 60 grains of powder since I have over a quarter inch of compression and do not need the velocity on this gun. Have a bear hunt booked for Nova Scotia this autumn and plan to take this number along as well to Africa next year. Thanks everyone for the advice, It sure came in handy.