Need help 338-378 wby

I just got a box of 285gr. Hornady match bullets and was wondering if anyone has any load data for them out of a 338-378 weatherby? would appricate any help i can get
Thank You
Ben

I have been shooting the 338-378 fronm the time it came out.I have had to research and almost make my own data.When I find data for the 300 gr bullet .I use it to start with for bullets such as your 285 gr bullet.I am fixing to do the same thing myself with the 285 gr barnes bullet for the 338-378.I have only used reloader 25 powder with alot of luck.I have gotten .25 " groups with it and 250 gr Nosler Partitions at 100 yards and just under an inch at 300 yards.I have also target shot 300 gr serria match kings ,275 gr swift a nd 275 gr kodiak bullets.I really like the 338-378 .Be sure to clean your barrel at least every 50 shots or it will shoot like a shotgun.If you have any questions give me a holler.I found a powder that will shoot a 300 gr bullet at 3000 fps or a 275 gr at 3100 fps out of a 26" barrel.I am going to try this powder with the 285 gr barnes.I have a bunch of old H-870 I am trying too.Be careful it can go from no pressurer to alot fast within a grain of powder.I like the Nosler partition 250 gr best on moose and bears and elk.It hits like a mack truck.We will see how this barnes 285 gr does.

I'd like to see any info on load info for the 338-378, including the rifle used. I've got a 338-378 Accumark and I'm trying to put some load data together. I might consider going to a longer barrel in the future but for now I'm just using
the barrel that is on it. I'm interested to see how the 285 Hornady performs.

Gus

Hey thanks mike. I really love my wby. too. I have done alot of messing around with my rifle also and have a decent loads worked up for it using the 225gr. Barns with 105gr of reloader 25. I know what you mean about having to figure out loads on your own. It seems like they have info for alot of the other 338. cal but never anything for the 338-378. I have a decent load also with the 265gr. Barns also using reloader 25. i never tested the velocity on them thow. I picked these hornady 285gr. because they have a purdy impressive bc on them. Also got tired of being on the waiting list for the Burgers and Matchkings. I am new to Long Rang Hunting so i am still learning how to use it but would appricate any help with reloading data for this gun you would be willing to give, and would be more then willing to share what data i have with you also.

I also use the Reloader 25 in my 338/378 Accumark that powder works great! I average about 40 fps shy of WBY factory ammo figures which with my chrono experience is a bit enthusiastic to start with. A moose or a bear won't be able to tell the difference between 3000 fps and 3100 fps anyways as bullet placement is what really counts for any caliber.

Just as a heads up guys I found that Retumbo has erratic pressures with bullets less than 250 grains, especially the 225 grain TTSX and Hornady SST. I contacted Barnes and they had the same experience and decided not to use it in their manual for that reason, neither does the latest Hornady manual. They recommended R25. I'm still waiting for the Barnes 265 TTSX to appear on store shelves here in northern Ontario but I would used the load data for the 250 grain and drop it about 3 to 4 grains to start and work up from there.

This is a great cartridge for sure and I took the time and effort to break in my barrel and it paid off in spades as I get almost no fouling at all but then again I give it a good scrubbing with Sweets every 20 rounds or so and never let the barrel heat more than me being able to hold on to the barrel. Should last me the rest of my life. I just wish we had bigger bears around here! LOL. Well we do have Polar bears just about 400 miles north of here but they are expensive to hunt. I hope this helps.

dgr416 said:

I have been shooting the 338-378 fronm the time it came out.I have had to research and almost make my own data.When I find data for the 300 gr bullet .I use it to start with for bullets such as your 285 gr bullet.I am fixing to do the same thing myself with the 285 gr barnes bullet for the 338-378.I have only used reloader 25 powder with alot of luck.I have gotten .25 " groups with it and 250 gr Nosler Partitions at 100 yards and just under an inch at 300 yards.I have also target shot 300 gr serria match kings ,275 gr swift a nd 275 gr kodiak bullets.I really like the 338-378 .Be sure to clean your barrel at least every 50 shots or it will shoot like a shotgun.If you have any questions give me a holler.I found a powder that will shoot a 300 gr bullet at 3000 fps or a 275 gr at 3100 fps out of a 26" barrel.I am going to try this powder with the 285 gr barnes.I have a bunch of old H-870 I am trying too.Be careful it can go from no pressurer to alot fast within a grain of powder.I like the Nosler partition 250 gr best on moose and bears and elk.It hits like a mack truck.We will see how this barnes 285 gr does.

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Come across your post. Can you message me what powder you have found to push the 300gr to 3000fps? What are you running in the 250gr Noslers? Thank you.