Guys

My .375 WeM loves the 250-grain Sierra with IMR 4064. The only "premium" bullet in that weight I can find is the GS Custom (HP) which looks more like an X-bullet. Barnes' 235-grainers are not quite accurate enough to suit me. I was wondering if you all have any experience to share with the HP and loads? I already have scads of good loads for other weight bullets, mostly around 4831 powder(s).

Thanx

BNagel

Kodiak bullets are available in a 250 gr .375.
Contact Alaska Bullet Works in Juneau.

.429

Not familiar with the "PSP" or "PP-HG " designations.

Thanks (so far)

Barry

Hey BNagel,
I never did much work with the lighter bullets in the .375 Weatherby.

I get the impression that the .375 Weatherby only begins to shine with 300 to 350-grain bullets.

Sure, it will beat the .375 H&H by a wee bit with the lighter bullets, but when you get into the 300 to 350-grainers it is a full 200 t0 250 fps better than the .375 H&H, and that requires powders slower than IMR-4064 to do it:
H4350 with 300 grainers at 2800 fps, and RL-22 or MRP with 350-grainers at 2650 fps.

My best 250-grain load was with the old Barnes XFB and 77 grains of RL-15: 2755 fps
The GSC HP should be close to the same data as the Barnes XFB.

My favorite light bullet load for the .375 Weatherby, for deer or varmints, is the Nosler Ballistic Tip 260-grainer and 78 grains of RL-15 giving 2818 fps and sub MOA for 3 shots.

I no longer have any use for the .375 H&H.

A .375 Weatherby will give superb accuracy and slower velocities with .375 H&H ammo, and way better velocity with .375 Weatherby ammo in 300 to 350-grain variety.

The 300-grainer will do it all, especially a monometal copper 300-grainer.

300-grainers are my preference for any use with the .375 Weatherby.

The most outstanding rifle load I have found thus far was the 300-grain Walterhog copy by Bridger, in my 24" barreled rechamber to .375 Wby of a Winchester M70 Stainless Classic, using the Dave Manson reamer of 2001 Weatherby specification:

0.139" for 3 shots at 100 yards
2717 fps
78-grains of RL-15
Hornady .375 H&H basic brass formed to .375 Weatherby
GM215 primer by Federal

However, that load had faint ejector marks on the brass.

78 grains of RL-15 seems to be a magic load for the .375 Weatherby, with any bullet lighter than 300-grains.

Thanks,man. I really appreciate your enthusiasm!

Barry

Barry,
Alrighty then! You are a good sport.

Here is some graphing I did back in the late 1980's with old data developed in the 1944-vintage .375 Weatherby throating:



This is a "meta-analysis" of Roy Weatherby and Frank Barnes claims for the IMR-4064 powder and bullets of 270, 250 and 235-grain weights.

I noted they claimed the same load and velocity for 270-grain bullets, but diverged as they decreased bullet weight and upped the powder charge.

X-axis is bullet weight in grains.
Y-axis is powder charge in grains of IMR-4064.
Velocity is inked in small figures beside the data points.
A couple of KE's are shown in parentheses beside the velocity, e.g., in the lower left corner of the graph:

235-grain bullet, 88 grains of IMR-4064, 3135 fps and 5125 ft-lbs KE

This graph is just a visual way of averaging the data and coming up with a ballpark powder charge and velocity expected.

We should of course start about 10% lower in powder charge and see if we can work up to 84 to 85 grains of IMR-4064 and get over 3000 fps with the 250-grainers, maybe even in my 24" barreled M70 with 2001 throat.

We know the .375 Wby will beat the .375 H&H, with any bullet weight, but it only really shines with the heavy bullets and slower powders.

If you cannot get well over 3000 fps with a 250-grainer, acceptable pressures, and excellent accuracy ... GET OVER IT!!! I did.

Of course that was back when I had a sloppy-throated 1944 pattern .375 Weatherby.

I might do better with the 2001 throat configuration on my M70 Stainless Classic.

So, Barry,
tell us more about your experiments with IMR-4064 and light bullets.
I might get inspired to try again.

Note: GSC claims up to 2900 fps with the 265-grain HV in a .375 H&H.

That is optimistic!

RIP

The only experimenting I do is trying to see if my rifle likes published loads. After finding my rechambered ZKK 602 (Weatherby-long leade, but that's as much as I know) liked 4831 a lot, it was only after looking through my "data" books that I'd forgotten to try IMR 4064 with something besides 300-grainers. Some left-over 250-grain Sierras my dad-in-law passed to me and re-reading "Cartridges of the World" pages on the .375 WeM gave me the idea to try 4064. Like most of my loads, I stumbled on one that grouped with three of five touching:

WW cases (from H&H) / GM215M primer / 73 grains IMR 4064 / OAL 3.600" no crimp / 2680 fps

The fastest I've ever gotten was 3000 fps with Barnes 235-grainer X's and that is with another published load.

A2 cases / CCI 250 primer / 90 grains IMR 4831 / OAL 3.550" crimp @ cannelure / 2900 fps

NORMA cases (from H&H) / GM215M primer / 90 grains IMR 4831 / OAL 3.550" crimp @ cannelure / 3000 fps

Disclaimer : for some of the above comments, "published loads" means that I've found max. loads for .375 H&H data are a good starting point for .375 WeM loading. Desiring to crimp @ bullet cannelures, I pretty well run out of case powder room before I can get a 4 or 5 grains spread like H&H data shows for min. to max. recommendations. Otherwise I just pull data from Barnes, Cartridges of the World, etc. and see if the ol' Brno likes them.

BNagel,
Thanks for the load data.
You have a very useful load with the 250-grainer, tames the .375Wby right down to darn gentle and accurate.

We hardly ever hear much about the HP bullets from GSC. I just went and looked at the list on the GSC website and noticed these .375 bullet weights:

HP: 200, 250, 270 grains
HV: 200, 240, 250, 265, and 300 grains

HP (moly-coated or not, your choice):



HV (much sexier bullet): YES AVAILABLE .375/250-GRAIN HV


200-grain HV at (CENSORED) fps from the .375 H&H.
Just imagine how fast it might go from the .375Wby.
.378Wby?

I'll have to go refresh myself on the antelope loads with a .378Wby and 200-grain HV. Lessee, where were those dead antelope pictures ...

250-grainers were the best light-weights for me, in .375 H&H, the 250-grain Sierra Game King was a one-shot black bear load for me, dead right there at 2700 fps. Perfect deer and varmint load.

Some sane loads from the Barnes manual for 250-grainers, I have always found their data good except about 100 to 150 fps optimistic on the velocities, most of the time for my rifles, but always safe:




It will be nice when Barnes publishes the next edition (Number 4) with some TSX data.

This is giving me a hankering for a .395/230-grain GSC HV or S&H Copper SHark.
The 400 NFBP 3" used a 230-grain bullet of .395 caliber.

230 Grain .395" is pretty stubby even in a HP.