At a recent gun show, I saw a .30-378 for sale. The guy told me that the gun was an original wildcat round. He said the gun is about 30 years old. He said he has shot deer at over 500 yards with it. He used it for long range target shooting, but it didn't have the huge target stock. Although it must've weighed as much as my leg. Does this round have any hunting use? I was also told that this round is now the Rem. 300 Ultra Mag. Any truth to this? I don't have any interest in buying the gun, just interest in knowing more.

To me the 30/378 is the ultimate .30

Its a bit more than the ultramag....not much but just a bit.

Yeah its a great long range hunting rifle.

At 500 yds its just getting started.

Not to start a piss contest, but IMO, whatever the 30-378 does, the .338-378 does better, farther, and faster.

R.

No arguments here.

30-378 is the big 30cal diff a long range gun and fare more power then a ultra mag

first, yes, this round has a LOT of hunting use. you can use it for anything from deer to moose with good quality bullets.

second, no, it is not the 300 RUM. it is a .378 Weatherby necked down to 30 caliber. the 300 RUM is a modified .404 Jeffery case IIRC.

and Rman, the 338-378 is a great round but it wont do anything faster than a comparable load in a 30-378. less bullet weight in the same case size means more velocity...

I dont know Marty...the 338/378 will shove a 300 grain SMK at 3K.

Dats fast and flat.

That's what I was talking about. That big 300 grainer will resist wind better and it scoots as well. Lighter bullets will go faster, but not as far, as well (if that makes sense). With all that case capacity, it just begs for the slick .338 bullets availible.

R.

I don't know how, within safe pressures, a 338-378 will get a 300 grain bullet to 3000 fps, but I do know a 30-378 will easily get a 200 grain Accubond to 3300 fps. At 800 yards, almost anything is in real trouble...

The BC of the 300 grain Berger at .891 averaged through the velocity bands will get to 1000 yards and beyound with more velocity and more smack than will any 30 cal 200 grain bullet. To fully appreciate the 338's one only has to shoot the 300 grainers at distance once

Wow Tom!
I would be curious as to what load and barrel length those numbers are from?
With my 338-378, about the best I could do with a 300gr SMK was 2800 or so-that out of a 26" tube.
Still, an accurate flat shooting SOB.

What powder and load? I know a lot of guy's getting 29 to 2950 with 300 SMK's out of 338/378

I get 2800 FPS out of my 338 Lapua with a 30" barrel and 92 grains of H-1000

JWP,
I was also using H1000, though I don't recall off the top of my head what charge weight.
2900-2950 is quite impressive.

IMHO H-1000 is just a tad fast in the large 338/378 case for top velocity. Retumbo, H-50BMG and US-869 being better able to add a bit more velocity. 3000 FPS is asking a lot of the 338/378. Darylle Cassle used a 338/416 Rigby with I believe had 38" barrel and achieved 3350 FPS with the 300 SMK, with which he took a Bull Elk at 2100 yards. I believe that his case life was, "shoot them once and throw away". The 378 Whea. is based on the 416 Rigby case.

Yes, I wish I had given the slower powders a try in my 338-378.
I sold mine about 6 years ago? and the slowest powder I tried was RL25. Even with that I was hard pressed to obtain 3000 fps with a 250 gr partition.
In my 340 Wby, I used to only use RL22 and IMR7828, but never saw great accuracy or outstanding velocity.
I finally tried RL25 in the 340, thinking it would probably be too slow-it works fantastic!
I see an easy 3100 fps with the 225 gr TSX and sub MOA accuracy.
I am pretty pleased with that.

My 338 Lapua is maybe average in speed with the 300 SMK, but it is extremely fast with the 250 SMk I got 3190 FPS with 98 grains of H-1000 and 3200 with 95 grains of R-25. These are book loads.

Every barrel is a law unto itself and no way to predict results until one shoots thenm over a Chronograph

Those 338's are awesome. We just need a super high BC 300 grain Accubond or similar...

Heck I would do cartwheels for a 350 gr accubond for my 375 snipetac!

The load was 111.5 grains of IMR 5010 loaded to an overall length of 4.135" with the 300 grain SMK bullet out of a 30" bbl.
Brass was 378 Weatherby and primers were Federal 215's

Another load to work up to is 110 grains of US869, with a 300 grain bullet.

R.

What happened to H870? About thirty-five years ago I bought a .30-.378 and used 118 grains of H870 with a Sierra bullet. I haven't seen it for awhile.

I traded it and the poor rifle burned in a fire before the new owner got to fire it. Life just ain't fair.

He probably started the fire so he wouldn't have to shoot the rifle!

R.

Thanks,Tom
There really are a good selection of slower burning powders these days.
I may just have to try another 338-378 sometime.

I have a friend and occsional hunting partner who shoots a 30/378. He used a 165 gr/ Barmes TSX. Uncertain of the powder charge. He took a moose at a bit under 400 yards and the damage was something to behold. Great for reaching out over unknown distances that are found around the edge of our northern lakes.

Jim

I bet that 165 TSX out of a 30/378 flat gets with the program!

I have given some thought to trying that same pill out of my 300 RUM as a long range deer/elk round.

I saw what was left of a jackrabbit hammered by a Warbird (same ballpark idea as the RUM and .30-.378) -launched 150. Dang, I just can't remember if it was a nosler ballistic tip or sierra matchking. In any event IMHO that qualifies as "heavy varminter."

Here's a hot potatoe for your .30-.378. 4001 fps thru the Chrony. The ultimate P-dog & antelope ammo for the discriminating glutton for fun.

?????

Yeah, dat'll flatten your shoulder fast.

I've been shooting one for 10+ years now, I really like it..I normally shoot the 180 MRX, and its impressed on everything from pronghorn to moose..longest kill was a big bull elk @ 800..even at range it WAY OVERPENETRATED!lol.Took out the far side shoulder on the way out, it was impressive.

I haven't shot any, cuz I dont have the twist for it, but I bet the 240 SMK isnt no slouch at LR, and the 30-378 could make that missile sail...Retumbo has been the best performing powder for me, well over 100 grains of it too..<grin> It will shoot my bullet of choice a molly-ed 180 MRX to 3500fps, but I backed off to where I found the sweet spot to be at 3430.

The rifle you seen for sale may be stamped 338-378 K&T (Kieth and Thompson) yes the Kieth is for Elmer Kieth. Roy first necked down the big 378 to 30 cal in the 50's IIRC, for the government..so ya, its been around a while before Weatherby started making factory rifles and stamped brass for it.