load data for 250g AB and .340 Weatherby?

[jmden]

Anybody shooting this combo? I've got data from Nosler and Hodgdon to start with, but wondered what folks' personal experience have been?

Thanks in advance,

Jon

 

[Long Time Long Ranger]

If you have a mk 5 wby action and standard wby freebore you may be able to shoot this load. Just start around 87 grains 7828 then work up and see where it goes. CCI 250 primers worked best in it. My best load with the 250 gets 3060 fps with 6 fps extreme spread in a 5 shot group with the 250 gameking at .565 BC. This is out of a 28" Hart barrel 1-10, with the wby freebore. I have taken elk at over 1000 yards with it. It is super accurate. Also the 210 scirroco with a .507 BC shoots well. 3285 fps with 5 fps spread.

 

[jmden]

Thanks, LTLR. I can hardly believe the fps you're getting out of the .340. That seems very fast for that cartridge. How many loads/case are you getting? I'm not doubting your data, it's just outside the norm. Must be a fast barrel.

 

[Long Time Long Ranger]

I have built quite a few 340's since the 70's. This is right in the range of all of them. I have never done one with a 28" or longer barrel that would not get over 3000 fps with the 250. In all the ones I have built this is not outside the norm if you have the wby freebore in your barrel. The load I listed does not have excessive pressure but I quit giving my exact loads on here in most cases because people would use it and not work up. Remember if you are looking at loading manuals you can easily start with the max loads if your rifle has freebore because the loads will be reduced by 10% across the board on most wby calibers. They do this because of liability concerns with so many custom variations with the wby calibers and either none or less freebore than in the mk 5 rifle. That is also the reason of the miconception most people have had through the years with wby rifles that they didn't perform much better than standard magnums. They are really loaded down in the loading manuals when many standard calibers are loaded right at max. I have always got way more out of the wby's than the loading manuals state. I have every wby caliber ever made except the 416 and 460 and have worked with them extensively since the late 60's. I have extensive data on most of them that shows what they will do in a freebore barrel if you work up with proper powders. I know you have a lot of experience and probably know all of this but may not know of all my work with the wby's.

I could not understand why the 340 wby never took off after the 250 gameking came out in the 70's with the high BC. I just don't think there were enough long range hunters then that really knew what was going on. Then the 300 and 338 ultramag comes along when many new high BC bullets become available and people jump on that bandwagon when the 340 will do virtually anything those rifles will and has been with us since the 60's. On average my 340's shoot about 75 fps slower than my 338-300 ultramags. So I really just never could understand what all the fuss was about all of a sudden. The 340 just got overlooked because it had been around forever I guess. When I want a big gun I shoot my 338-378 which will blow these little guys clear out of the water.

My son and I were shooting this evening getting ready for a caribou hunt and had several guns out there. He had a blast busting gallon jugs full of water with 200 grain noslers at 3615 fps. Shot a 1.5" group with it at 400 yards. Pretty impressive rifle.

If I can help you with the 340 just let me know. What length barrel is it and does it have the wby freebore?

 

[jmden]

Thanks, LTLR. The rifle is my father-in-law's with the WBY freebore and a 24" barrel.

 

[Long Time Long Ranger]

With a 24" barrel the faster burning powders work best and will not get the velocity the longer barrels will get with the slow burning powders. 4350 has always been a good performer in shorter barrels. Powders slower than that have a huge muzzle flash as quite a bit of the powder is burning just beyond your barrel where I am getting the extra velocity. 4350 and similar burn rate powders will get you more burn inside the short tube and better overall performance

 

[sdeviation]

im using 250 AB< 80grains, H4831, in a 24 inch pipe no free bore averaging 2800fps

 

[Long Time Long Ranger]

Good load, I got good velocity with winchester WMR in a 24" barrel which is essentially ball 4831. IMR 4350 has done very well in the short barreled 340's.

 

[tuher]

ltlr
am using 340 in weatherby accumark 26 inch barrel, would like to use barnes 250gr triple shock boat tail. any data available you can share?
tom