30-378 Weatherby Mag?

[Shmackey]

I decided to do a little research on some of the overbore cartridges that use .308 projectiles. I'm very familiar with .300 WM, and I knew that .300 RUM took it to another level. But my hornady loading manual has data for 30-378 Wby Mag that makes .300 RUM look quaint. And they claim it was designed for long-range competition.

Has anyone here shot a rifle chambered in this caliber? I'm intrigued.

 

[56hawk]

I haven't shot one, but I do have a 460 Weatherby that is based on the same case. By the way, I believe Roy Weatherby designed the 30-378 to meet a government contract to push a bullet over 6000 fps. I don't doubt it since I have got around 4600 fps out of my 460.

 

[Shmackey]

I just read that it's essentially a .460 Wby Mag necked down to .308.

Oh crap. I might have to have one.

 

[56hawk]

Yeah, it seems like a pretty cool cartridge. Though I'm also tempted to get a 338-378 or a 378 for that matter.

 

[X-Rap]

I have the 338 based on the same case and love it.

 

[RPRNY]

I have fired a Weatherby Mark V in 30-378 and I do not wish to do so again. Super magnums are not my thing but I'm not an opponent of anyone else doing their thing.

It's a screamer, that's for sure. As I recall (it was over 10 years ago in Dubai) I was shooting 165 gr Noslers (?) over more than 100 grs of 4831! The rifle had a muzzle brake and generous recoil pad. I shot from prone. I understand detached retina syndrome.

I'm not a huge fan of recoil and I'm not a good enough shot to know what to do with @ 2500 fps at 500 yards. It was a Sheik's rifle and I believe he was headed off to hunt mega horned sheep in Pakistan. That sounds like a reasonable use for it. Not my cup of tea.

I think 338 Lapua is the latest and greatest in this realm (although I guess 30-378) still tops it for speed. It'll be expensive - brass, new barrels plus a pound of powder every 10 rounds but it sure isn't ubiquitous!

 

[Shmackey]

I don't suppose you can get a plain old sporter rifle from Rem or Win or Ruger in this chambering? Do you have to go straight to Mister Weatherby?

 

[56hawk]

Yeah, I think your choices would be a Weatherby or a custom rifle maker. Not going to be cheap either way.

 

[HOOfan_1]

More likely you have to go straight to a custom barrel.

Edit: well I'll be apparently Weatherby does produce rifles in that cartridge

http://www.weatherby.com/product/selector/rifles

 

[GooseGestapo]

I have a .300RUM and have shot a .30/378wby.
If it's another "level" above the .300RUM, then the .30/06 is another "level" above the .308 (hint, it aint!)

In fact, depending on barrel, ammo, and atmospheric conditions, it's a "wash" in many instances.

The rifle I shot was a factory Weatherby MkV Super-something. Heavy, fluted barrel, stainless steel w/decent synthetic stock and muzzle brake. Had something like a 4-15x Swarovski or NightForce scope on it.
The individual was at a public range on state property trying to sight it in. He couldn't.
I offered to help him.
1. I removed bolt and "bore sighted" it at 25yds. The shop who sold it to him had done so with a collimater/bore scope and due to height of scope over bore was "way, way off" vertically.
He hadn't helped by running the windage all the way to the left trying to center the group.
2. After firing one shot and correcting it at 25yds, I moved it to 100yds. One shot and then moved the scope to get +2.5" high at 100yds. Then fired 3 more rounds to verify. Got a nice 1.1" group centered and backed away from bench and allowed "OWNER" to shoot it. He missed the 18" tall x 24" wide target 3 times !!!! (flinch !!!!!). (shooting from an "Outers" gun rest with a pad against shoulder.

I shrugged my shoulders and suggested he take the rifle back and trade it for a Vanguard in .243wcf. He did !!! Rifle was back in the rack the next week....

He'd shot a box and 1/2 before my "intervention", and returned the rifle with 6 rds. Ammo was 180gr w/A-frame bullets.... IRRC. Cost him almost $100.00 a box.

I didn't think the rifle "kicked" all that bad. Muzzle blast was very significant. Not quite a .50BMG, but getting there.

For 99.97% of hunters and hunting, it's "over the top". For some target applications, it's great. If I had one, I'd be feeding it what I feed my .300RUM, WC-860, or WC-872.
But, I only occasionally take my .300RUM to the range, and have only used it twice to hunt with in the last two years, hadn't hunted with it before then since 2006....
But, where I was hunting on an airport, it was the "cats meow".... The 180gr Hornady SST "popped" a doe like a ripe tomato at a lased 387yds.... with only ~4" of hold-over. Load was 100.5g of Retumbo for a chrono'd 3,360fps @ 30'. (26" bbl w/0.375" freebore).

On deer, the .300RUM doesn't do anything my .257wby Vanguard doesn't. The "little" Weatherby kicks and barks about like a .270, but shoots as flat as a .220Swift. What's not to like????

 

[Shmackey]

I have a .300RUM and have shot a .30/378wby.
If it's another "level" above the .300RUM, then the .30/06 is another "level" above the .308 (hint, it aint!)

In fact, depending on barrel, ammo, and atmospheric conditions, it's a "wash" in many instances.

But ... This one goes to eleven.

 

[dubbleA]

But ... This one goes to eleven.

Gotta love Spinal Tap quotes brother !!!


I built a 300 Kong (30-378 WBY IMP) years ago, think it was back in 1990. It's a basic 378 WBYcase with a blown out conventional shoulder and does away with that double radius nonsense. This was way before the 30-378 was a factory cartridge and I used a set of custom form dies from RCBS to make cases for it. Back in the day the slowest powders available were R-22,H1000,IMR7828 which are surpassed by todays ultra slow powders made for thses use case capacitys.

The need for speed slowly erroded from my needs and it just sits in the back of a safe these days. It took copious amounts of powder to get it to run, nearky twice that of a 30-06 for a average 10-15% gain in speed. If memory serves me right the case holds 136grs of water and my loads were using 115-122 grs of powder. It 's 28 inch tube pushed the then new Nosler 180 gr Ballistic Tip right along at 3500+ fps. I had an exceptional muzzle brade put on it and the rifle actually pulls away from you when fired so no recoil what so ever. The concussion is something to behold, I thinks it's worse than shooting my 50BMG.

I am still a.30 cal fan and have a pretty good arsenal of rifles chambered in varoius .308" magnums.

The 50BMG(far left) is just for comparison. The 300 kong is next to it and then the 300RUM...as you can see it does go to "11"






I was once a huge 378 WBY fan also but finally succumbed to selling it. I still have plenty of ammo and brass for it if anyone is interested

 

[critter]

Just beware. Forget the 'kick'. The barrel life is like eight rounds before it burns out. ;-)

 

[Kachok]

Crazy high recoil, eats custom barrles like nachos, and costs $6 a shot....oh goody where can I get one
I will keep playing with my wimpy little 308 and 30-06 for 30 cals.

 

[Shmackey]

Recoil isn't important, I can install a barrel, and I don't buy factory ammo.

 

[snake284]

I just read that it's essentially a .460 Wby Mag necked down to .308.

Oh crap. I might have to have one.

More precisely, hinting to its name, it's a .378 WBY Mag. necked down to .308. But the 460 is the parent cartridge of the .378 I believe.

This thing is a beast. I have a regular old garden variety .300 WBY Mag. and it's all I can handle. It's a great cartridge and shoots very flat, and will take any game the mega 30s will. And the more overbore a cartridge is, the shorter the barrel life of the rifle. The 30-.378 is a real blow torch to the chamber throat area.

 

[DieselvRR]

I actually have a Weatherby Mark V in 30-378 that I will be putting up for sale soon. The 30-378 is a high velocity round with a lot of recoil. If you have a muzzle break on, it helps a little but still feel it. It will take down about anything you shoot!

 

[redneck2]

I had a customer at our LGS that had one when they first came out. One of those guys that had to have the biggest, baddest, fastest. As noted, muzzle blast was brutal with the muzzle brake. Nobody was willing to shoot it without.

IIRC, accuracy was going downhill after about 750 rounds. He sold it for cheap to finance the next loser project.

A fact of physics....for every increase in powder capacity of 10%, you get a velocity increase of 2 1/2%. Diminishing returns and all that.

 

[MachIVshooter]

From a 30"+ barrel, the .30-378 will edge out the .300 RUM, .300 Dakota, .300 Pegasus, 7.82 Warbird, etc. But from a 24" or 26" barrel, it really can't make good use of the extra 10-15 gr. powder capacity advantage it has over the other uber-.300's. Just too much to burn in a .308" bore of "normal" length. And, as noted, throat life is even less than the other big mamma jammas.

 

[X-Rap]

If it were the only big gun I were to own I would pick something a little more generic but if you have a 06 or a 308 I see no reason not to indulge yourself, if you already have one of the 300 mag sized then it probably isn't worth it.