30-378 245 gr Berger EOL Load Data?

[Machine]

Hello,
I recently acquired a Weatherby Mark V in 30-378 wby. To feed it, I purchased Berger 245 gr EOL slugs for it. I also purchased the Berger reloading manual because none of my other manuals had 245 gr info.

Problem is the Berger manual doesn’t have 245 gr info either. The Berger manual tops out at 230 gr.

Does any one have data for this caliber and bullet weight combo? I’ll probably be using H1000 as that’s what I have on hand in the big jug and in today’s environment, it’s nearly impossible to get new supplies.

Thank you,

Josh

 

[LA50SHOOTER]

Hello,
I recently acquired a Weatherby Mark V in 30-378 wby. To feed it, I purchased Berger 245 gr EOL slugs for it. I also purchased the Berger reloading manual because none of my other manuals had 245 gr info.

Problem is the Berger manual doesn’t have 245 gr info either. The Berger manual tops out at 230 gr.

Does any one have data for this caliber and bullet weight combo? I’ll probably be using H1000 as that’s what I have on hand in the big jug and in today’s environment, it’s nearly impossible to get new supplies.

Thank you,

Josh

Josh;

The free-bore length will make a difference and I don't really know how the Wheatherby's in this caliber are throated, I'd presume long but that is only an assumption. Also, your COAL would be another important factor to consider. - I'm away at work so I'm not able to access my Quick-Load program or I could plug some values in and run a scenario with H-1000 for you, so unfortunately I'm not much help right now. - If you can find someone with Quick-Load and provide some more information I'm sure that a "starting" load could be calculated. - I know that during the current situation with availability of components we sometimes are forced to compromise if we are going to continue to shoot. - I feel H-1000 is probably a bit on the fast side for the 245 gr. - If you could find H50-BMG, Reloder 33 or Reloder 50, or V/V N570, 24N41 or 20N29 I think you'd achieve better results. Also there is US-869, WC-870 & WC-872 if you wanted to try some slower spherical (ball) powders that are slower in burn rate than H-1000

 

[Evlshnngns]

In the past, calling Berger would get you some good info. Worth a shot.

 

[B23]

In the past, calling Berger would get you some good info. Worth a shot.

Yeah that, X2!

 

[30378]

You possibly could have stability issues with 245s. Wby 30-378 bbls are 10 twist. Probably a little slow for 245s.

 

[cuznguido]

I would love to be able to help you out, but I have never shot anything that heavy in mine. Several of the above mentioned powders will work nicely for you though. 215 gr is heaviest I have shot in mine, but it is a fun caliber to load for and to shoot. Hope you figure it out. I have also heard much about the alleged excessive freebore in the weatherby but I must not be smart enough to know that it hurts my accuracy. My old Weatherby shoots just fine and yours probably will too.

 

[Kurz]

You possibly could have stability issues with 245s. Wby 30-378 bbls are 10 twist. Probably a little slow for 245s.

This is your answer as pointed out above and most importantly by Berger. Berger suggests/requires a 1:9" twist rate as upheld by the calculations using their Stability Calculator. Since Weatherby still hasn't entered the faster twist rate competition, you will probably need to forego shooting this in your factory barrel.

As an aside, by manipulating the calculator you can achieve some semblance of stability by shooting at altitudes above 6,000 feet...

Enjoy!

 

[Orr89rocz]

Calc seems to come up with marginally stable at sealevel and 2900-2950 fps. 1.2-1.25. Can that still shoot good?
Reason i ask is i have shot a 1.07-1.1 stability factor for a tipped gameking in .257 and it seems to fly ok and grouped decent at 550 yards. Maybe further out it wont be as good im not sure

 

[4xforfun]

This is your answer as pointed out above and most importantly by Berger. Berger suggests/requires a 1:9" twist rate as upheld by the calculations using their Stability Calculator. Since Weatherby still hasn't entered the faster twist rate competition, you will probably need to forego shooting this in your factory barrel.

As an aside, by manipulating the calculator you can achieve some semblance of stability by shooting at altitudes above 6,000 feet...

Enj

I have an experement for you. Measure up a 55 gr Nostler Balistic Tip Bullet. Punch it into the Berger calc. Use 14 twist tube.

Remember....100's of millions of 55 NBT's have been shot out of a 14 twist something or other. Pretty much EVERY rem 700 223, 22-250, 220 swift etc....... is a 14 twist.

My point.....the Berger Calc is NOT your wife...you don't have to listen to it. You DO need to test.

 

[6MMsteve]

100 grs of retumbo

 

[B23]

Also, it's important to keep in mind just because you are below the optimum stability factor doesn't mean a bullet still can't group well. It'll just be at a reduced BC and it will fall off sooner the further out you shoot.

 

[6MMsteve]

do a percent of wt to powder ratio from the 230 you should get close would start with low load on 230

 

[LA50SHOOTER]

The practicality of shooting the 245 gr. Berger's in a 26" barreled rifle using H-1000 leaves something on the table IMO. - The 215 gr. Berger (and a few others - 200 thru 220 gr weight class) would be IMO a better choice especially trying to use H-1000. - If it was me, I'd try to sell or trade the 245's for something more compatible with a 26" barrel if I only had H-1000 as a powder choice.
- The 245's belong with a 30" or longer 9"- 9.25" twist barrel & some slow (RL-33 or RL-50 or N570) burning powder.

 

[Whisky Tahoe Foxtrot]

Whenever I need Berger data not in the book, I call their Tech Support Line... +1 (660) 460-2802
They'll share what they have if it isn't in the book. If it is in the book, they'll give you the page number

Be ready to write, they tend to test nearly everything and will give you case volume percentage which is helpful. They won't share pressure data as they consider that proprietary info.

 

[davidjoe]

I love these rifles but I do cringe a bit at reading of a Mark V and heavy-bullet hand loads. That’s not really their forte in my opinion because they all come with relatively light barrels, moderate twists and lengths and an overbore cartridge optimized for Roy Weatherby’s emphasis on “Velocity” for the “flattest” shooting option in a caliber.

I’m sure I am not the only one that has sometimes wondered if a given Mark V barrel shouldn’t have been a little thicker, including my own Accumark 30-378. And I have a TRR LM Mark V that is even thinner with a bigger bore, that’s factory fluted. Point being, that if heavies force everything to squirm, contort, recoil and “bulge” - I hate to acknowledge that but it does happen to thin barrels as the bullet passes, more than light bullets do, then there’s a real possibility I think with these huge cases to develop pressure that could stretch these thin to moderately made barrels, while causing them to flex on recoil beyond their design envelope even before that happens, inhibiting good accuracy.