Any 30-378 guys?

[B23]

Considering I have pushed a 180gr Accubond up to 3230 fps in a 300 win mag, a load using 200gr in a 30-378 at 3200 fps is a not a hot load by any means. The 30-378 can push a 200gr much faster than that.

I have also pushed the 220gr Berger up over 3200 fps in my 300 Norma Mag Improved rifle. Still a smaller case than the 378 WBY.

Case capacities:
300 NMI, 35 deg shoulder and straightened body: 110gr H2O

30-378 Weatherby: 133gr H2O

The 30-338 Lapua Improved w/35 degree shoulder is 122gr H2O

I have a 300 AX which is Kirby Allen's version of a 30-338 Lapua Improved w/35 degree shoulder. My 300 AX has a Lilja 10tw finished at 28in less brake and I'm pushing 230 Berger's 3250 fps with 106gr US869. I've run it as high as 108gr and it clocked those 230's a little over 3400fps but it was leaving a pretty heavy ejector mark too. In mine 106gr US869 with those 230's is the sweet spot.

I don't understand why you would have a big 30-378 then only load it to 300 RUM speeds.

 

[ebb]

I bought a Sako rifle chambered in 30-378. Never fired one shot through it. Sent it to gunsmith for rock creek barrel in 338 lapua. Couldn't be happier.

 

[Murray Brook]

Well in my Mark V I've tried RL-33 Norma 217 H-870 H-5010 as well as a few more slow burners and appx 3240 is my max velocity with 200 gr bullets. I've pushed them to 3300 ft/sec but always got pressure signs so I backed off. Most of the reloading manuals seem to agree. Maybe I've got a slow barrel.

 

[Ledd Slinger]

Well in my Mark V I've tried RL-33 Norma 217 H-870 H-5010 as well as a few more slow burners and appx 3240 is my max velocity with 200 gr bullets. I've pushed them to 3300 ft/sec but always got pressure signs so I backed off. Most of the reloading manuals seem to agree. Maybe I've got a slow barrel.

Interesting. Maybe a slow barrel or too slow of a powder for that light of a bullet.

Weatherby lists their 200gr Nosler Partition factory ammunition at 3160 fps and factory ammo is usually always loaded well below max pressures

 

[JBT47]

Ask your friend to read this thread before deciding on the .30-378. Had a rifle chambered in it years ago. There are better .30 cal choices with similar performance with heavy bullets. .300 Norma Improved with 35 degree shoulder using Lapua brass would be much more enjoyable to own.

 

[Downeast]

.300 RUM and the 30-378 are almost kissing cousins when it comes to velocity with 180's. Using Wby brass I have 5 loadings on some of the 30-378 brass (annealed after 3 firings) and it still functions well. I have the Accumark and it is a hunting rifle so it will outlive me. I shoot 210 Berger VLD Hunting bullets and it shoots 1 moa out to 500 yards, which is my hunting range limit with this rifle. It's a great round for what it is. Like all "Bee's", they are hunting rifles and they are very good at what they do.

 

[B23]

While 30-378 Weatherby is certainly no slouch, the Lazzeroni 7.82 Warbird would be the biggest, badest 308 caliber available.
Reload data showing a 200gr bullet at 3,358 fps.

Seems like everyone forgets Lazzeroni when looking for speed.
Not mainstream enough i guess.

Per a conversation I had with John a few years back his 7.82 Warbird has a case capacity of 127gr H2O which is a bit under the big Weatherby.

 

[std7mag]

But runs at higher pressures.
Weatherby tyically about 62,000.
Lazzeroni at 68,000.

 

[EasyShooter]

We have a barrel coming now. Ordered a 30 cal Bartlein barrel, straight taper to 1” at 32”. Plans are probably to cut it to 30”. Haven't ordered a reamer yet. Brass wise I am 100% convinced there are better choices for big 30 caliber cartridges than 30-378. Some of them come very close to 30-378 velocities but no one has mentioned accuracy. How do these big 30 caliber cartridges compare accuracy wise? I know the build of the gun is going to be a bigger factor in accuracy than cartridge choice. The 30-378 does have different shoulder than many others. I’m usually more concerned about accuracy than velocity. I don’t even take out my chronograph until I find a bullet/powder combination that works good.

 

[EasyShooter]

Well I got the rifle finished. It is a 30-378. Barrel is 31” long, slightly tapered to 1” at the muzzle and very heavy. Total weight is just under 15lbs. I am thinking some mercury in the stock might be a good thing. The once fired brass I got is getting stuck in the chamber. There is a slight bulge on the brass just above the belt that isn’t coming out with the sizer die. I am thinking the rifle that originally shot this brass might have had a lot of headspace causing the bulge in the brass. New brass and ammo is on the way.

 

[EasyShooter]

Here you can see the bulge in the brass. This is where it is getting stuck in the chamber.

 

[LA50SHOOTER]

View attachment 1214761Here you can see the bulge in the brass. This is where it is getting stuck in the chamber.

I would use New brass and for-go any once fired brass in this caliber. The original Weatherby (which is Norma), Norma, and Nosler brands are about the best that I’ve tried. - I haven’t tried the Hornady brand.

Barrel length will make a good bit of difference in this cartridge, and IMO a 30” would be the shortest I’d run unless there’s no way to accommodate it. 32” would even be better. The slowest of powders with the heavier bullets are going to “want” that extra length to be able to achieve the best velocities. (H50-BMG is a good choice for the 230’s, 245’s &250’s)

 

[jeffreybehr]

I admire those of us who are pursuing MAXIMUM performance.. They have goals and are willing to pay the prices for the very high performance.. My story is a little different.. I've always been a bit sensitive to high recoil and got moreso a few years ago with a worn-out right shoulder.. In 2007 and '8, after shooting a 16-pound 6.5-284 Shehane in 1000-yd. BR, sometimes very well, usually not so well, and wearing out three barrels, I gave up the entire long-range-shooting hobby.. In 2017 I got back into owning and tuning a similar Savage 12BR rifle, but this was during the time that my shoulder was wearing out and hurt from high recoil.. The original barrel was in 6.54-284, I quickly replaced that with a new barrel in 6.5 Creedmoor, and I quickly replaced that with a 30"er in 6XC.. THAT I could shoot comfortably, but I guess I had consumed all the passion I had for all this and just gave it all up--again. The rifle...

...still stands in my safe.

I can't even conceive of the recoil energy of a BIG .308; I guess that's why I'm now loading for an incoming AR15 in 6mm ARC.. But this almost-77-year-old and new right-shouler joint are doing very well, and I'm really enjoying working up loads for this little 16"-barreled, 6-plus-pound UBR.

 

[dragman]

I have ran a few big 30's.
Most notable was a 300RUM on a Python i was running a 30" brux 10 twist and shooting 208 Amax's at 3335fps with 103.3 grains of RL33

have fun with the project and enjoy! chasing crazy power is a lot of fun lol