Looked around a bit and didn’t see any load data for the .257 Weatherby. I’ve got one coming in and not sure where to start. Looking for loads mainly for whitetail.

100 grain TTSX is the bullet of choice for many. Easy to get to shoot, lightning fast and deadly.

Thank you….what powders are best?

I really like H1000 and highly recommend temperature stable powders. R22 and R25 work well, but watch the heat!

I load 110 Accubonds for mine. I use IMR 4350

I have a bunch of RE-22 and Maybe I’ll try and find some H-1000 to try.

My brother had a good load running with Rl 22, seems that I remember h1000 being a good choice but that is going off of memory. I have not loaded for it yet, but it will be this summer. Keep us posted.

have had the best accuracy in a hunting bullet in 100 grain with either 100 gr. Nosler Partiton or Swift A-Frames and they do kill bigger Whitetail and Mule bucks excellent , with my 257 Weatherby mags. for many years. Reloader 22 and 25 have worked just fine in the fall for hunting in my rifles.

Fill case with 7828, cork with 100gr bullet of your choice, watch deer wilt. 85s can be dramatic killers too.

I too would suggest 7828. RL 22 as a second option.

I’ve mainly used 7828 and H1000, but RL22 is a favorite of many. My current 24” rifle likes the 115NPT with 7828 at 3,350fps. The 100gr version seems like the best fit here, but I had the heavier bullet already on hand.

Id buy a few reloading books!!!!!

R22 and the 100TSX was my go-to in the .257 Weatherby.

I have an old 1954 12 twist FN 257 Mag, it loves 100gr A Frames and TTSX's with blue tips removed, the load is an easy 3500 fps with 65gr Norma 204 powder, that modest powder charge is easy on the throat, keeps barrel heat down and doesn't have near the muzzle blast as buds 257 Mag. using 80gr in his loads with another powder, i have only shot three or four deer and pigs with that rifle, they will melt before your eyes, next to no recoil lets you stay in the glass and see it all.

Currently toying around with mine with rl26 and 110gr Sierra TGK. It shows some promise but there’s not a lot of rl26 data out there. Sierra states some in their newest manual but that bullet hadn’t quite hit the market yet I don’t guess. With the generous freebore weatherbys have do you guys that have a lot of experience loading them find pressure signs then back down some? Whats the method to you fellas’ madness?

Great choice of cartridge. I've owned and loaded for a gaggle of 257's. I much prefer the heavier bullets as they buck the wind and don't run out of steam as fast as the lighter bullets. My go to powder is RL-25 with a 115 NBT. It has consistently provided the best combination of accuracy and speed across the range of 257's I've loaded for. Additionally, I've found the 115 NBT to hold up well at 257 Wby velocities. My second choice would be H-1000 coupled with a 110 AB. Also consistently accurate and fast. As an aside though, I have found the 110 AB to quickly pressure spike when at or very close to max. Nothing terribly significant though. Just approach the upper end with caution.

for the guys that use H-1000 what kind of velocities are you getting , i never seem to get as fast of velocities as i do with Rl. 22 example 100 N.P. RL 22 3700 -3800 fps? i have also notice RL. 25 does shoot nice rounded groups too. anyone using Hammer bullets now ? i just got my Weatherby mark 5 finished with a bedding job i put a Brux barrel contour 4 ,7 1/2 twist , 28 inch long , chambered in a 257 Weatherby mag. with my reamer. so i will now be gettin it ready for out west on a antelope hunt . wanna use the heavier grain 25 caliber bullets in this new rifle build so that`s why i ask these questions. would like too use either Berger 135 gr. ,B.J. bullets or Hammer bullets , probably RL. 22 or RL. 25 but if H-1000 works i might use that too ? thanks,Pete53

Five of us use RL-25 or RL-33 with the 115 Berger. Either one makes them scream.

As for load data:

Nosler:
https://www.nosler.com/load-data/caliber-and-cartridge-data.html

Hodgdon:
https://www.hodgdonreloading.com/

I have always used RE22, CCI mag primers and 100 gr. TTSX at 3700 fps. Have killed a pile of critters, elk, deer, antelope and all DRT. Punches WAY over its weight limit.

Thanks for the comment, I have several reloading books but I thought I'd ask for some pet loads here first. I'm a very experienced reloader for many years, but I just thought I'd ask the good people here first.

Great Info, Thank you!

Nice, I've always been a fan of the TTSX's.

https://alliantpowder.com/reloaders/RecipeList.aspx?gtypeid=2

https://www.speer.com/reloading/rifle-data.html

Plus if you download the hornady app you can get loading data for a single cartridge for 99 cents or all of the data for $19.99. Of course there’s the hardback version also.

You're most welcome, those early FN Southgate Weatherby's sure are some cool old rifles, Roy really put a lot into their builds, good luck getting your rifle up and smoking some game this season.

Using the Barnes 100gr TTSX, I've tried 7828, Magnum, H1000, and Retumbo. In a SS Vanguard MOA. Best accuracy with H1000 and Retumbo but Retumbo is slightly faster. Norma/Weatherby brass, Fed 215 primer. Mule Deer's favorite load uses the 100gr Nosler E-tip and H1000. Search this site to find the exact load. Good luck! Mark and Belle

I can provide a little range update for my trip the range with some test rounds using IMR 4831 and the TTSX 100 gr bullet from Barnes. I used the CCi 250 LRM primer. OAL was 3.17 inches. I loaded 63gr, 64 gr, 65 gr 65.5 gr and 66 grain. I chose these loads because most research I have done shows the best loads at 1.5 to 2 grains over book max and I wanted to work up to that range. I stopped there because I only had 15 rounds of brass ready. The Barnes Load Data had max loading at 64 grains for 3842 fps. I do not have a chronograph.

Loads 63gr, 64 gr and 65 grain all shot to the same poi roughly and were all submoa. 65.5 and 66 shot to a poi of 1.5" higher and the groups widened to about 1.5 MOA. I did not see any pressure signs with any of the charges.

63 gr was 0.81", 64 gr was 0.66" and 65 gr was 0.48". There is a giant asterisk around 65 gr because it was only 2 shots who grouped just liked previous charges and in the same spot. The third shot was distracted as some paper on the back stop blew in front of my target just as I was releasing....

65.5 gr shot to 1.61" and 66gr shot to 1.58".

My plan is to load to the 64 gr book max, in the center of a 2 grain window that all shoots similar. At 3500 fps, it should be enough of the good stuff to work reliably.

Rifle is a Weatherby Accuguard. Hopefully these same rounds will shoot great in my CLR when I get it back from Melvin soon.