Home Forums Hunting & Shooting Express Rifles and Big Bores Only 375 Wby for 350 Grn Bullets

Well I need to go the a WOA (Weatherby Owners Anonymous) as I am working on getting my 5th Weatherby rifle build going.

Anyways I decided to do a 375 (Not 378) Wby. Mainly cause it’s a simple fire form process. Then it dawned on me that with the increase in powder capacity I should be able to load it with a 350 Grain Barnes TSX and be able to get it to move at its optimal velocity (Probably any other 350 Grain bullet)

Does anyone have any advice on the cartridge and bullet combination?

Not gonna change my mind I am going to stick with 375 Wby, mainly cause I got most all I need for it coming (Reamer, Dies, Barrel)

The 375 Weatherby is a great round!

The 300 grain TSX is a great bullet.

I see no need to go to the 350 grain bullet as the 300 at 2750fps has always worked so well on anything I've stuck one through.

Woodleighs will give more room for powder before you crimp at the cannelure. ZKK 602 rechamber, BTW.
I got 81 grains IMR 4831 which is compressed enough to keep the bullet from jamming into cases due to recoil.
Not sure of the speed, but likely similar to that of a 350-grain RHINO with 76 grains W W 760 [2400 fps] in mine.
Ray Atkinson likes the Woodleigh on buffalo. (I can only talk about losing a blue wildebeest with the RHINO.)

Ok then,,,,, I agree, there is no need for any thing more than the 300gr NP, I get right @ 2620-2650 fps out of my Rifle w/ 22" Bbl., and with proper shot placement, I've rarely needed a 2nd round, let alone a 3rd. My Rifle holds 4-down & 1-up.
Albeit, I've never Hunted Africa,,,,, yet.
Lj

AK375DGR, that is a slick rifle. I planned on building mine with a 24 inch barrel but after seeing yours I may go down to 22 inch!

Agazain, would you wanna tell more? I am building this rifle as a buddy of mine and me plan on going to Africa to hunt, and I mainly wanna go for a wildebeest. I just figure a heavy bullet going at it’s recommend speed would be more efficient, but I do not claim to know anything when it comes down to actual application on big game.

I live by the phrase over kill is underrated, just as the ground hogs I kill.

Thanks guys!

Blue wildebeest can soak up lead ("poor man's buffalo"), especially if alert to what you are doing. Shoot for CNS / to hit the backbone where it intersects with "right up the front leg".
I was on heart meds still, recovering from heart surgery, etc. Just didn't hit mine anywhere important, so to speak, I guess. The RHINO was first into the chest mostly broadside, and a 250-grain TTSX a few minutes later didn't stop him from jumping a sheep fence where my PH was sure he'd stop. Wish I had shot again as he got to the fence but Philip said no. We followed blood and tracks next day, but he never died, Oh, well!

That 350 grain TSX is a long 'un, like the RHINO. Couldn't get enough IMR 4350 under it to get over 2150 fps. RL-15 wasn't available to me then. IMR 4320 and 4064 might work, but I wanted a just compressed load as stated above. With the driving bands, you can crimp a couple places, long as the magazine is right for that and it shoots with accuracy. That's a bunch of money to try lots of powders, though.

Love to hear of your success in the future. I have a full write-up at AR where I am BNagel.

http://forums.accuratereloading.com/eve/forums/a/tpc/f/6321043/m/6101070742

I used 350gn Woodleighs in my H&H. They ran right at 2400fps with softs and solids and less than MOA.
Took the 2 buff and the wildebeest was at 350 yards.

I would check the original reamer specifications to see if the 375 had much free bore. Even though factory ammo is not much of a consideration the free bore may give you just the right amount of lead for the 350s. Raptor has some really long 375s up to 450 grains. No first hand experience but the 350 Weldcore followed by 350 Barnes X would be a potent combo. I have also heard many people that had the opinion that somewhere around 2,800 fps was a short of holy grail number for bullet performance, could be.

I had this done. At 2598fps with a 300 grain Sierra SBT they'll make a one-hole group. Pretty amazing. Light recoil.

Kevin Thomas who wrote "There is Something about Buffalo" thought very highly of the 380 grain Rhino. It was tested on buffalo in it's initial development and was modified three times to improve performance. They should do even better in the Weatherby. If in a herd situation I would use the Woodleigh but the heavier one may still give pass through.

With Weatherby's long free bore longer bullets should work fine. Be sure it's reamed to Wby specs. Their factory ammo is designed for that.

I shoot a bit of factory 300gr partition ammo in my Sako/FN custom 375 Wby and tried some 350 Woodleighs years ago. I didn't blue-pill the woodleighs, since my gun is built on an FN Supreme action and isn't as robust as MK Vs. Still, the first Wbys were on the same action that I have.

The 350 Woodleighs were plenty accurate, BTW, even at moderate velocities.

So... the heaviest I've shot from my 375's... Just basic 375 H&H rifles. Is 300 gr bullets.

Is there a serious advantage to the 350's?

Thanks, Guy

No.

Use A-Frames or TSXs in conventional weights.

+1

I re-chambered my 24" barreled 'Classic Stainless' Model 70 in 375H&H to the Weatherby in the mid 90's IRRC.
The performance is a genuine 200fps+ gain in all bullet weights, the brass stops growing/stretching and is easy to size and load for.
My own testing has shown that at 65,000psi is where most max loads sit.
With the 260gr Accubond I get 3000fps with a max load.
With the 270gr Woodleigh PP/RNSN I get 2950fps with a max load.
With the 300gr Woodleigh PP/RNSN I get 2830fps with a max load.
The 2 powders I get my best results with are Win760 and H4350, unfortunately, neither speed nor accuracy was obtained with RE15, which was disappointing, as this powder is used in my 500Nitro exclusively and I have a large quantity.

I will say that the Weatherby round physically rocks animals more emphatically when hit by it in comparison to the H&H.
It's almost like they've been hit with a larger cal it's that noticeable.

It's one of the best conversions out there for troublefree loading/sizing due to less brass stretch, trimming required and ease of sizing.
I highly recommend it, you WILL NOT regret building one...........ever!

Cheers.