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.404 necked to 375, vs .375 Rem Ultra mag

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11 November 2006, 20:35
AfricanHunter
.404 necked to 375, vs .375 Rem Ultra mag
I'm not rying to start a bonfire, so hold the match. From a practical using standpoint, whats the difference? I would think none, but I could be wrong. I am not interestd in either one as the H&H is fine with me and I gave up the .378 and .375 Weatherby cartridges long ago.
11 November 2006, 21:08
RIP
No Significant difference, but the rims and body/head diameters are slightly different.

My .404 Jeffery brass by Norma has no rebate. RUM brass is rebated.

Saeed's .375/404 (.375 UAE) has top secret shoulder angle and throat specs, but they are very similar to those of the .375 RUM.

Both cartridges are about 120 grains water capacity +/- 1 grain, though the RUM has a few thou bigger base diameter.

The nonrebated rim alone is enough to make Saeed's version superior.

I believe the .375 UAE was born by necking down .416 Dakota brass with the shoulder moved to whatever secret angle and location gives the current neck length on his cartridges, which are now made by fireforming .404 Jeffery brass.

I'll bet they both use a 12" twist. Wink
11 November 2006, 21:42
jeffeosso
quote:
Originally posted by RIP:
No Significant difference, but the rims and body/head diameters are slightly different.


What Ron said


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
11 November 2006, 22:37
RIP
Jeffe,
Thanks for not taking offense at the rebate remark.

I'll concede that the tiny rebate on the RUM is no problem if the rifle is properly smithed to feed well, but not to be trusted to mass production.

RUM brass max head/base diameter would be 0.550" and max rim diameter would be 0.534", IIRC.

.416 Dakota specs are .545" base and .545" rim.

.404 Jeffery specs may be found that show .542" base and .538" rim.

In reality, my .404 Jeffery Norma brass is 0.542" base and .542" rim, same as my .416 Dakota.

I think Norma made both the .416 Dakota and the .404 Jeffery brass I have from the same basic case.

In reality, the .375 RUM brass is a little smaller than the max spec, as it should be to be a smooth fit for function.

IIRC the measures I got on .375 RUM brass were .547" base and .532" rim.

Could "sumbuddy who know" (a phrase I learned from Overkill) confirm this?

I think the .375 RUM brass is a bit heavier than .404 Jeffery brass, and is certainly strong stuff, good brass at a great price. thumb

Even Saeed could use .375 RUM brass sized down a little to fire in his .375 UAE, or whatever .404 Jeffery Wildcat he might have on hand. The rims will be an easy fit and functional in any decent rifle.
11 November 2006, 23:35
vapodog
quote:
whats the difference? I would think none,


Me too!


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13 November 2006, 17:54
AfricanHunter
quote:
Originally posted by vapodog:
quote:
whats the difference? I would think none,


Me too!


Man-a-live, I got out of that one without getting stoned to death! Thanks for the responses.
13 November 2006, 18:55
jeffeosso
Rip,
nah, if I can't take ribbing about facts, well, that would be a pretty miserable life, no?

Yeah, it's rebated.. but feeding issues are nonexistant for the ARs

jeffe


opinions vary band of bubbas and STC hunting Club

Information on Ammoguide about
the416AR, 458AR, 470AR, 500AR
What is an AR round? Case Drawings 416-458-470AR and 500AR.
476AR,
http://www.weaponsmith.com
13 November 2006, 20:34
butchloc
just for .02 worth - i've got a 375 dakota & use H&H data to load it. i know it's supposed to be a bit more than an H&H but i don't see it without running pressures to a point I don't like to see.