Talk:.300 Remington Ultra Magnum

Ballistic performance and test barrel length

Due to this cartridge very large case capacity in relation to its bore size a 24 in (609.6 mm) long barrel as used in the “info box - ballistic performance” section gives not the most realistic examples of the .300 Remington Ultra Magnum or its ballistic twins ballistic potential, though the stated performance figures in this article are very credible. Barrels that are too short in relation to the employed cartridge will produce sub standard muzzle velocities, unnecessary recoil and lots of muzzle flash, smoke and report. The main cause for these effects is unburned propellant. Custom made rifles for these kind of super magnum cartridges generally sport 762 mm (30 in) or longer barrels to take advantage of the ballistic potential of these overbore cartridges. Francis Flinch 13:03, 3 September 2007 (UTC)

the long barrels than can be created, the goal of the infobox isn't to show the max that could be done, it's to show typical realistic usage. No standard rifle manufacturer delivers .300 RUM in a barrel longer than 26". If you want to mention that better ballistics could be achieved in a longer barrel, feel free to add it to the article, but recognize that this is true of almost every cartridge in existence. Powder burn efficiency is a factor of not only cartridge size, but shape, neck diameter, barrel length, powder type, powder burn-rate, bullet weight, temperature, etc. I don't see any reason to bear all these facts out on every .30 caliber magnum cartridge page. Arthurrh 17:55, 7 September 2007 (UTC)

I have to agree with Arthurrh. I would go one step further and delete the Accurate Powder information. Not that the Accurate Powder company is incorrect but that there are many different powder companies that publish .300 RUM loads. I would prefer to use Reminigton published loads for velocity and muzzle energy. Having said that, Remington uses a 26 inch test barrel for .300 RUM loads.

I would also like to remove the part about the .300 RUM being more efficient than the .30-378 Weatherby. See below.

I am a major in ballistics and your saying that the .300 RUM is not being efficient as the .30-378 Weatherby is wrong. In fact the .300 RUM under ballistics test is just as good and somewhat better than the .30-378 Weatherby. —Preceding unsigned comment added by 71.193.163.82 (talk) 03:59, 7 July 2009 (UTC)

Efficiency

A common misconception is that cartridge (powder) efficiency or bore to cartridge capacity is lineal or proportionate. That is, if I use 10 percent more powder I should get 10 percent more velocity and/or muzzle energy. This is incorrect and will never happen between two separate cartridges of differing, bore, case geometry or capacity (all other things being equal).

The reason is because a 10 percent increases in powder is a 10 percent increase in energy. Energy is not proportionate like force. Energy is a function of the square; v². The square root of 10 is 3.2. Therefore a 10 percent increase in powder will tend to support a 3 percent increase in muzzle velocity. The muzzle energy is dependant on the weight of the bullet; the greater the weight the greater the percentage of increases in muzzle energy.

Now couple that with the fact the .300 RUM operates at a high mean chamber pressure than the .30-378 Weatherby Mag (65,000 and 63,800 PSI respectively) and on paper there is virtual no difference between the two cartridges.Greg Glover (talk) 01:14, 20 February 2008 (UTC)

.300 Remington Ultra Magnum is used by sniper rifle?

I have a doubt: Is .300 Remington Ultra Magnum is used by sniper rifle? If yes, by what army?Agre22 (talk) 15:51, 13 October 2009 (UTC)agre22

not been used in any wars. Removing the service history non-information. DeusImperator (talk) 04:00, 28 October 2013 (UTC)

Comparison table error

With equal bullet weights and muzzle velocity, I think the muzzle energies should be the same. Possibly just a typo, I'm not sure which of the two red numbers are incorrect:

.300 RUM performance comparisons

Cartridge	Bullet Weight	Muzzle velocity	Muzzle energy
.300 RUM	200	3154	4419
.300 WSM	200	2822	3638
.300 RSAUM	200	2790	3458
.300 Win Mag	200	2822	3538
7.62 Jonson	200	2935	3826
.300 Wby Mag	200	2987	3963
.30-378 Wby Mag	200	3160	4434

Article Classification

After reviewing this article, I have removed the stub rating and pushed it directly to B. -Deathsythe (talk) 18:40, 26 April 2011 (UTC)

Dead link

During several automated bot runs the following external link was found to be unavailable. Please check if the link is in fact down and fix or remove it in that case!

• http://www.accuratepowder.com/data/PerCaliber2Guide/Rifle/Standarddata(Rifle)/308Cal(7.82mm)/300%20RUM%20Remington%20Ultra%20Magnum%20pages%20272%20to%20275.pdf
  • In .300 Remington Ultra Magnum on 2011-05-20 21:36:24, 404 Not Found
  • In .300 Remington Ultra Magnum on 2011-06-20 03:03:04, 404 Not Found

--JeffGBot (talk) 03:03, 20 June 2011 (UTC)

Advertising for obscure proprietary cartridge

"Among commercially-produced .30-caliber rifle chamberings, The .300 Remington Ultra Magnum is third to the .30-378 Weatherby Magnum and the Lazzeroni 7.82 Warbird in cartridge-case capacity, the Warbird being the fastest and "the best as well""

The Lazzeroni cartridges are obscure proprietary cartridges with little adoption among sportsmen. They're not notable enough to feature in this article, especially not with a silly statement like "the best as well" attached. I've removed the reference. Bananabananabanana (talk) 19:55, 22 April 2012 (UTC)

Cartridge History

As somewhat of a historian I would like to keep the pedigree of the RUM cartridges as it is. The information is accurate the issue here is citing information which currently is only found in blogs and forums which I do not want to cite. Yes I know everyone and their dog can create a blog and forum knowledge is no knowledge at all. These is base on a periodical a while ago and an first hand interview. Every cartridge has a history to tell. For example, an interview with Arthur Alphin provided the history for the .458 Lott "Napkin in a diner". DeusImperator (talk) 03:57, 28 October 2013 (UTC)

caliber designation

The .300 Remington Ultra Mag is described as "...a 7.62mm (.300 inch) caliber...." but, as indicated in the chart, and as with all 30 caliber rifle cartridges, the bullet diameter is .308 (7.82mm), although at least 2 "30 caliber" rifles use a bullet diameter of .308-.310 (7.62x39M43) or .308-.312 (32-20 Winchester). It might be useful to point out that 7.62mm IS equal to .300 caliber, but "30 caliber" is a marketing tool more so than an accurate caliber designation. Cdoc42 (talk) 15:22, 30 August 2015 (UTC)