Barnes .338 280 gr LRX in 338-378 Wby

[lynxpilot]

Bought a box of Barnes LRX (.338 / 280 gr) all copper bullets. They claim they are designed for 'long range'. They also tag them with "Lapua" and in the description on the website, do so to emphasize that the bullets need a strong push to get them to velocities where they are optimized for long range.

I have a Weatherby Mk V in 338-378 but Barnes provides about zilch in load data. I'm inclined to start a workup using available load data for similar weight bullets (like SMK 300 gr).

Anybody tried this combo of bullet and cartridge? Would like to at least get in the ballpark for starting and maximum loads. I have pretty much all of the powders that could fit into this category (H-1000/H50BMG/US869/H-4831). If somebody has a sweet load for this combo and is willing to part with that info, that would be ideal as opener is this coming Saturday.

 

[idaho elk hunter]

I use the 280 almost exclusively in the 338-378. The highest bragging rights go to the 265 Barnes with 111.2 gr RL25. 3211 fps. This is a top max load. The 280 will trail behind it with 109 gr at 3170 fps. RL 25 is VERY temp sensitive. Retumbo is what I am switching to. My coal is 3.80. N570, H870, 869, 872. NONE of them gave the accuracy or the speed with out going to a compressed load. The Berger, Accubond, Sierra, Hornady Amax do not give the accuracy in the factory barrel. This is what I have found in several of the Mark V and Accumarks that I have tuned. Hex coat the bullets If you can. It definitely keep the barrel ALOT cleaner. For some reason it does not affect velocity in the caliber as much as other calibers. And for all sakes do not even think about starting at my loads. ONLY use Win Mag Primers. Pm me back with your findings.

 

[lynxpilot]

Thanks for the quick comeback. I just got back from my permanent home, now I'm at my work home 4 hours away. I actually have RL25 but it's at the other place. I have H50BMG, H-1000, and US869 here with me now. I'll try to translate your loads using percentages and interpolate out to something in the H-1000 (low range of course). I'll have to try the RL-25 when I go back to the home front.

By the way, I re-barreled mine with a Bartlein and it's just about 30" long, so whatever ills go with the Weatherby stock barrel won't apply here. I also get quite a bit more MV. I was sending the Sierra MK 300's out at 3,000 fps where the stock barrel was significantly less.

 

[lynxpilot]

Just looked at Barnes website load data and min/max charge weight for the bullets they showed comparing H-1000 and RL 25 were within 1 gr, so it seems they are very close. I'll try your COAL at a slightly lesser charge weight. I'll also let you know how it turns out.

 

[idaho elk hunter]

Be careful with a rebarreled Weatherby. Many smiths do not put the Weatherby engineered freebore in the chamber. If that is the case then all loads out of manuals and others will be drastically different.

Added barrel length in the caliber will result in 20 to 25 fps per inch of barrel.

For a side note, I have worked with a lot of these since they have come out. From Complete rail guns to hunting rifles. The 5c Broughton will outshoot all other barrels in this Cartridge. I am a Retired Weatherby gun builder/ smith and for the life of me I have never seen how one specific manufacture and type of barrel works with one cartridge better all the others. The 5c and Tim's unique lapping process has to work harmoniously with the internal ballistics of this cartridge.

 

[lynxpilot]

When I sent the Bartlein to the smithy, I asked him about his chambering cutter and he reckoned it was from Weatherby specs, allowing for Weatherby's long freebore. I'll keep the charges down just to be safe. Might also take COAL down a tad to keep clear of the lands.

 

[emptygun7]

Just wondering if you ever got a load figured out for the retumbo, recently got a 338-378 weatherby custom shop but load data on a barns lrx 280 is still nonexistent 8 years later.... Just a place to start at this point would be great...thanks

Be careful with a rebarreled Weatherby. Many smiths do not put the Weatherby engineered freebore in the chamber. If that is the case then all loads out of manuals and others will be drastically different.

Added barrel length in the caliber will result in 20 to 25 fps per inch of barrel.

For a side note, I have worked with a lot of these since they have come out. From Complete rail guns to hunting rifles. The 5c Broughton will outshoot all other barrels in this Cartridge. I am a Retired Weatherby gun builder/ smith and for the life of me I have never seen how one specific manufacture and type of barrel works with one cartridge better all the others. The 5c and Tim's unique lapping process has to work harmoniously with the internal ballistics of this cartridge.

 

[Gregg C]

I had a 338-378 Wby .i had the same problem. I'll search my old posts......

 

[Gregg C]

Just wondering if you ever got a load figured out for the retumbo, recently got a 338-378 weatherby custom shop but load data on a barns lrx 280 is still nonexistent 8 years later.... Just a place to start at this point would be great...thanks

Sorry, I came up empty. If I may suggest, Quickload ? Start a new thread in reloading, asking for help, possibly some one with that program can hook you up.
I'd forgotten how little data there is for that cartridge... Good luck !