I did a search but a lot of the posts are several years old so I thought I would ask...

What are some favorite loads for the 375 Weatherby with 270 or 300 grain bullets?

You didn't get a lot of action on this did you?My 375 Wby was built on a P-14 action and it definetly has a preference for IMR 4350 with the 270 & 300 gr bullets. I use Fed 215 primers to get things started. Good groups so I never did a lot of other testing.

In my 375 AI, I had great success using RL-19, with your given bullet weights.

You just never know what bait will get a strike!

Thanks!

Anyone using H4350?

Mine seems to perform the best overall with R22 and Fed. 215 primers. I have tried H4350, R19 and several others but always hit the pressure limit before I was anywhere close to what I thought would be top velocity.

quote:

Originally posted by McCray:
You just never know what bait will get a strike!

Thanks!

Anyone using H4350?

John S has one of those tight-throated D'arcy Echols custom rifles.
He cannot handle well a top load of H4350, and requires the slower RL22,
probably 92 grains, identical to the top MRP load with 300-grainers.

Use H4350 Extreme (an SC powder that meters well) for top performance in the standard throat of 2001 .375 Wby spec.
I do believe that is a CIP spec also.

Norma loads the Weatherby factory ammo with 88 grains of something and the Nosler 300-grain Partition.

That will do an honest 2800 fps in a 26" barreled Weatherby factory rifle and +2740 fps in my 24"-barreled Winchester M70 Classic Stainless.

I duplicate that load with 88 grains of H4350.
Best load I have found, and about max in a 3.6" box.
Load them out to 3.80" in a CZ box and you can go a little higher.

Rip,

I have a very similar gun to yours. Mod 70 375 H&H stainless reamed to 375 Wea and I had the factory barrel trimmed to 24". Mine will Chrono 2800 and change with the factory ammo.
Wish I knew what powder Norma uses!

EZ

Guess I should of mentioned that mine is a stainless Winchester with the 3.60" mag box. Barrel is 26 inches.

Chamber was cut with a Manson reamer with a .370" throat.

I'll try H4350. I have a bunch of it and am currently on a kick to stick with temp stable powders.

McCray,
Same reamer as mine. That is the good one.

eezridr,
Was not your factory barrel 24" to start with, like mine?
You got a fast barrel.

RIP,

You are correct, I just crowned the barrel . I have another Mod 70 stainless is a 338 that had a 26" tube; I trimmed it to 24".
Another great load discontinued for some reason was the Federal HE's in 250 gr partition in 338. They chronoed at 2800. I bought 10 boxes. Still have 9 and they are accurate!
I love this 375 Weatherby!