240 Wby Mag Heaviest Bullet???

[257Roberts]

I believe these are all 1:10 twist barrels, does the higher velocity gain any bullet weight advantage?

I was curious if folks have had any kind of respectable accuracy with the 103-108gr range?

 

[Gary in MD]

The extra velocity, in the 10 twist, will probably not get you any extra bullet weight (longer bullets with higher bc).
You're probably going to max out in the 100 grain range, depending on how long the bullet is. The 100 grain Sierra and 95 grain Ballistic tip shot the best in my 240 with the factory 10 twist. It now has a 7.5 twist and does well with the higher bc Bergers.
Incidentally, I think some of the newer factory 240s are coming with fast twist barrels, but someone can correct me if I'm wrong.

 

[Kurz]

Incidentally, I think some of the newer factory 240s are coming with fast twist barrels, but someone can correct me if I'm wrong.

Fast Twist (1:7.5"): Featured in premium models (like the Mark V Apex) to handle modern, longer bullets (105+ grains) for increased accuracy and range.

From Weatherby:

*As of 01/01/2024 the twist rate for .240 WBY MAG and .243 WIN was updated from 1:10 to 1:7.5

Finally!

 

[CJ6]

Buddy runs a 240 Wea. with a Krieger 10 tw. with 105 Bergers. They're stable out to 880 yds. on his home range.

 

[Frankm]

Mine will shoot 105 AMaxes very good but they re shorter than 108 Eldm. 100 gr and less it really likes. (100 TGK, 90 TGK, 80 Eld VT, etc)

 

[Idaho-Lefty]

For, a "Sure Thing",.. Accurate and Deer / Antelope, stomping, Bullet,.. Try, the 95 grain Berger Classic Hunter's, in your 1-10 Twist Barrel.
The Heavier / Longer, High BC, Berger Bullets, "May" NOT, fully, "stabilize" in some, 10 twist barrels.
The Classic Hunters are easy, to get to,. "Shoot",.. WELL !

 

[dk17hmr]

At one time I had a 10 twist 243 super rock chucker (6-06AI mostly) that would shoot 105gr amax really well at 3450fps. I live at 6200' asl so maybe that helps also.

 

[Kurz]

6mm in 1:10 twist barrels never thrilled me, ever. The PPC and 6mmbr in slow twists never even got any notice from me.

The first .240 WBY I built was specifically for hunting Coues deer at longer ranges in southern AZ. Lots of rough terrain and mostly 400-600 yard shot potentials. I used Bartleins almost exclusively so it was always a wait to get anything slightly off center, so I ordered two or more to start with in the 1:8" twist. I was shooting the Hornady 105 grain AMAX which worked well in the slightly faster twist. When the 110 grain A-Tips showed up I switched to the 1:7" twist.

I chambered these barrels for the 26" length for both bullets. I was good for out to about 700 yards and maybe a touch more with the A-Tips. Fortunately, all of my shots could be held to 600 yards or less. It's not very easy to attempt to creep through this terrain and slight vegetation to get closer.

The 6mm cartridges are great for the Coues deer since they are smaller in stature than the Midwestern whitetail. Choose the proper bullet and know your ranges.

Enjoy

 

[Gary in MD]

6mm in 1:10 twist barrels never thrilled me, ever. The PPC and 6mmbr in slow twists never even got any notice from me.

The first .240 WBY I built was specifically for hunting Coues deer at longer ranges in southern AZ. Lots of rough terrain and mostly 400-600 yard shot potentials. I used Bartleins almost exclusively so it was always a wait to get anything slightly off center, so I ordered two or more to start with in the 1:8" twist. I was shooting the Hornady 105 grain AMAX which worked well in the slightly faster twist. When the 110 grain A-Tips showed up I switched to the 1:7" twist.

I chambered these barrels for the 26" length for both bullets. I was good for out to about 700 yards and maybe a touch more with the A-Tips. Fortunately, all of my shots could be held to 600 yards or less. It's not very easy to attempt to creep through this terrain and slight vegetation to get closer.

The 6mm cartridges are great for the Coues deer since they are smaller in stature than the Midwestern whitetail. Choose the proper bullet and know your ranges.

Enjoy

Interested in the powders that you used and velocities that you achieved with the heavys.

 

[Rem Jim]

I believe these are all 1:10 twist barrels, does the higher velocity gain any bullet weight advantage?

I was curious if folks have had any kind of respectable accuracy with the 103-108gr range?

My MK5 ultra light likes the Nosler 95 BT with lots of RL26 powder at 3600 fps .
Sorry this is the heaviest I have shot .

 

[Kurz]

Currently, I have loads using Norma MRP running about 3,200+/- with the 105/110 bullets. Norma has discontinued the distribution of their powders here in the U.S. so I bought up quite a bit of it when it was still available.

ADDED:

I extended the throat on my rifles so bullets are seated slightly long.