Home Forums Hunting & Shooting Ask The Gunwriters .30-378? Opinions

You're letting the semantics in #'s 2 and 3 get in the way of (alleged) mechanical issues in #1.

I cannot say there are problems with rebated rims. But in a thought experiment, suppose there are.

Then why do they occur? They occur precisely because the rim of the case is smaller than the next part of the case after the extractor groove. Whether this is a belt or the bottom of the body is immaterial. If you don't call it rebated because it's belted, not using the word doesn't make the dimensional difference go away where it counts.

So whether it's called rebated of flugelbitted, the Weatherby has a larger dimensional difference where it counts. If the "properly rebated" RUM is to be criticized for this, then the flugelbitted Weatherby should be as well.

I understand your point, and it makes perfect sense except I don't think the issues with rebated rims are really constructed. I think the issue is more to the amount the rim size is reduced to fit the extractor. It seems to me (guided by Wayne Van Zwoll's guide to Long Range Shooting), that the rim difference in the .300 RUM isn't significant enough to cause real problems, especially when paired with a Remington extractor.

So, in reality the issue isn't really one of semantics, but degree. The differential between the Weatherby base and rim is inconsequential while the difference in the .300 RUM may be greater, it's still considerably less than a .425 WR (where the difference is stark). That being said, I would choose the Weatherby because I like them and one is being dangled in my face so really the .300 RUM isn't even a valid part of the discussion at this point. But the casing discussion has been interesting.

Go back and check out the drawing for the 300 Winchester. It's rim is the same diameter as it's belt.

So the Weatherby really does have more of a rebated rim than the Remington.

At least I'm getting through to someone.

You guys are killing me. Apparently the discussion of rebated rims hasn't been one of choice around here.

Rebated rims don't bother me, and I don't have reason to believe either cartridge has a problem.

It's just that you brought up the Ultra being rebated as a negative the Weatherby doesn't have. Yet, even if you don't want to use the word rebated to describe it, the Weatherby has more of the effective dimensional difference that would cause the problem attributed to a rebated cartridge.

I know and if I ever do this again I hope a swarm of locust attack my keyboard.

As JWP said the 300 ultra is a much better choice.
With an ultra you don't have to deal with belted cases, expensive brass, and Weatherby guns.
My model 70 300 ultra feeds as well as any gun I have, including a 1909 Argentine in original trim.

If someone was dangling a .300 RUM in front of my face then I might be inclined to agree, but that's really not the case.

And the gun in question is a Sako, not a Weatherby.

But the brass is expensive.

In your opinion.

Before I looked at the .338 Lapua Improved, I did check out the 300/338-378 case. I spoke to quite a few people who had firsthand experience with this cartridge. While the 300/338-378 case has around 10 grains more capacity than the Lapua Improved case, the results were to be considered the same. Once the quality of brass was examined, as well as the limited life of said brass when compared to Lapua brass, the decision became less difficult to make. If an ultra-big boomer is a requirement, maybe look at the 300 Lapua Improved, or a 300-338 Norma Improved?

R.

The only way a 30-378 makes sense to me is with at least a 30" barrel with a 9 twist to stabilize the 240 SMK. At 3000 FPS this makes a very good long range stick with the ability to go to near 2000 yards with accuacy.

I wouldn't own one with a 26" barrel on a bet, just too much muzzle blast for me in a barrel below 30 or so inches

I've noticed with a 26 inch barrel (as most factory guns in both chamberings wear) that the differences in velocity with like bullet weights are pretty negligable between the RUM and the Weatherby. I like the RUM better, but it's economics for me. mtmuley

I can see 3200fps with a 200gr NP or AB out of my (300 RUM)M700 26" bbl easily.
I can't imagine a 30-378 doing a lot better?

Very true the added powder capacity of the Weatherby doesn't help much untill about 30" of barrel

I much prefer the Rum in a 26 inch barrel. Actually I prefer the RUM in any barrel length and have 4 of them

I've gotten 3250 out of a 26" RUM with 200 AB's

Nice.
What powder are you using for that load, jwp??

Retumbo. The 3250 FPS load was with a batch that was a bit on the slow side. The next batch that I bought was a bit on the fast side and I could not work up to the old load without blowing primers.

Thanks, jwp.
Retumbo is what I use as well.