375 RUM reloading info/tips needed

[Northman999]

Fellows,

I've got an XCR in .375 RUM on the way and I'm looking for some tips from you guys who have already been reloading it. Here's some specific questions I have, but anything you want to share would be appreciated:

1. I've got about 1K of CCI #250 magnum rifle primers that I use for .338 win mag and .375 H&H, but no .375 RUM loads that I have found list that as a primer for thier loads - I'm kind of thinking that "a magnum rifle primer is a magnum rifle primer", and brand isn't really important - am I okay to use the same primers as I use in my other magnums?

2. Power loads - I'll be honest and say up front that I want to push 300gr bullets as fast as I possibly can in my 24" barrel. I don't mind working up loads, slowly and carefully. There seems quite a fair variation among bullet makers on max velocity (Barnes is saying only 2823 fps with ther TSX, Sierra is saying 2950 fps wth their gameking - my two bullets of choice) and I just noticed that Nosler reduced their max velocity (ontheir web page) from 3005 fps to about 2855 fps with thier 300 grain pills. This, and of course, some of these manuals I know for a fact are underrating some cartridges by at least 200 fps. What are guys who are willing to work up power loads actually getting with 300's?

3. Bullets - I've had great experience with Sierra Gamekings and Nosler Partitions in other calibers, and I've been dying to try TSX's. I just checked Wholesale sports for prices - Gamekings - 32.99, TSX's 57.99, Partitions 70.99. What are you guys finding is a good all around bullet; and I may be shooting bears at 50 feet or moose at 500-600 yards in case it matters. I've found the gamekings great in 375H&H and they cost about half of the others, but no experience with the RUM yet. Any other bullet reccomendations.

Thanks in advance!

 

[Boomer]

I use Remington 91/2M and Federal 215 interchangeably with no noticeable difference. Your CCI's will be fine, and because they are a hair larger in diameter you might get an extra load or two out of your brass.

I found that H-4350 seems to be close to the correct burning rate with bullet weights from 260-380 grs. I've used H-4831 and found that there is no velocity advantage and that the loads are compressed (a condition a try to avoid) while pressure remains on the low side. Hodgdon has a new powder out that I'm wanting to try called Hybrid 100V. This powder has a burning rate that falls midway between 4350 and 4831. The name Hybrid comes from the powder being a combination of ball and extruded giving the best properties of each. Given it's burning rate and the fact that loading densities can be higher, I expect velocities can be increased in the .375 RUM and the .375 Ruger. The testing I did earlier in the winter with the Ruger left me wanting more speed from the 260 gr Noslers although the 300 gr TSX's met my expectations.

At any time you'll find Nosler 260 gr Accubonds, Hornady 270 gr Interlocks, 300 gr TSX, and 380 gr Rhinos on my loading bench. Hornady's bullets are cheap enough for practice, plinking, medium game hunting when loaded to reduced velocity, and small game hunting when loaded to low velocity. (18 grs of Unique gives me 1200 fps). The 260 gr Noslers I believe are accurate hard hitting bullets for medium sized game when the range might be on the long side. The 300 gr TSX is a good all around bullet, especially useful if big bears are around when I am hunting something else. The 380 gr Rhino is my bear protection bullet. If I ever get another trip to Africa it will also be my cape buffalo bullet. With enough weight and velocity to produce good penetration, and expansion approaching 1", it takes the .375 into the big bore category.

I think with the velocities that are possible from the Ultra in a long barreled rifle you are best to choose a premium bullet. The Sierras are accurate, but they would not be my choice of bullet when the MV exceeds 2700 fps. Try the TSX's and if you like them just think how much cheaper they are than Swifts! While I am critical of X bullets in general, if you want a good "go-to" bullet for all applications the 300 gr TSX would be hard to beat.

High velocity is not why I chose this cartridge though, it was so that I could achieve H&H velocities in a short barrel, which it does with a little to spare.

 

[Northman999]

Thanks for the very informative post Boomer, you were actually one of the guys I was specifically hoping to hear from. Where do you get your Rhinos BTW, and would you have any reccomended loads for them? I'd probably like to get a box and work up some loads for close range situations where I need to really drop the hammer on something dangerous.

 

[Boomer]

I bought my last batch directly from Rhino in South Africa and the price worked out to about $3.00 per bullet. Clearly to spend this much on bullets alone you need a reason to use them, and I can justify it, but for most folks a 300 gr TSX would do fine. My load for the Rhino is 84.0 grs of H-4350, and this gives me 2300 fps from my 20" barrel.

 

[grit]

In the 375 RUM I had, I found it to be very accurate with RL19 and the 300gr nosler would leave the barrel @ 2800 with 98grs and the 270 X bullets would do slightly bettwer than 3000 with 100grs of it. The 375 Rum is an excellent caliber for moose/bear.