300 Ultra Mag? Help me decide


December 29, 2008, 08:05 PM
I'm considering buying a new rifle and I'm pretty interested in a 300 UM (specifically a Remmy Sendaro) but I don't know all that much about it. So, I thought I'd come to yall for some opinions and info.

I'm just getting back into shooting rifles after a 15-year hiatus- when we had to sell my collection and my dad's collection to pay his medical bills, I just quit shooting and hunting with a rifle. My 2 favorite rifles growing up were my 30-06 (whitetail & mulies) and my .375 H&H (elk & moose)- both pre-'64 Model 70's. I just don't have the budget to buy those rifles these days- particularly the .375. So, I thought the 300 UM out of a Remington Sendaro model would be a great option that, with different loads, would cover a wide range of hunting AND give me a good platform for doing some long range paper-punching. Suddenly I've gotten the itch to get back to the range and to do some of the target shooting I was so good at as a kid.

I live and hunt, mostly, in South TX so there isn't a whole lot of need for the high-end power of a 300 UM but I'm a huge fan of Elmer Keith and his infamous motto. Plus, I may have the opportunity to go on some elk hunts over the next year or two and there is quite a bit of exotic hunting around where I live, which includes some pretty big game species. The thing I like so much about the idea of the 300 UM is the versatility, depending on the load you choose; and, from what I've heard, it's a very accurate cartridge when shot out of a good box rifle like the Remington 700 Sendaro.

The other calibers I'm considering are the 300 Win Mag and the .308

Can y'all give me some advice/encouragement on choosing the 300 UM or give me some reasons why I should choose the other calibers. I know each has it's own ups and downs but I'm looking for a good all-around caliber that gives me as many options as possible; with the least shortcomings.

Thanks very much for your input!


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December 29, 2008, 08:29 PM
I shoot a remington 700 Model 700 Sendero SF II (custom work done to mine) in .300 RUM for long range tactical precision challenges. You hear a lot of people talk down about the .300 RUM but for me being able to take anything in North America just by selecting a different cartridge and a minor scope adjustment is a huge step in the right direction. Plus you mention the average of only 25-39 inches of drop out to 500 yards means it is flat as you can get.

Now you can take anything in north america with a 30-06 also so i am not saying the 300 rum is the only one that can do it but other calibers may not have the power the .300 Rum does. One thing is finding Ammo for the 300 rum. but it can be done. Also might look at getting a muzzle brake installed on it (get a cap so youe dont have to hunt with the brake on). Fox river makes an awesome brake for the money. Good luck figuring it out.

Oh and if you want to save some cash the 700 PSS comes in 300 RUM.

December 29, 2008, 08:58 PM
300 rum would certainly do the trick. Under most circumstances I think a 300 win mag would be just as good, with less kick, cheaper ammo and better ammo availability. But if you handload and are non-recoil averse(hey you had a .375), the ultra mag may be the way to go.

December 29, 2008, 11:21 PM
My hunting partner and I both bought Remington’s in 300RUM when they first came out. He got the sendero, I got the blued, wood, with sights model. There was no brass available at the time so we each bought 5 boxes of Remington 180 gr. loaded with Nosler partitions. We shot side by side at the range through the same chronograph to get an idea of actual speed and group size. Now here's the good part. Mine averaged 15-20 fps slower than the factory claimed 3300 fps. The sendero was actually 15-20 fps faster than the factory stated 3300 fps. It had an after market muzzle brake and it cut the felt recoil about in half. I will tell you this, I also shoot a Colt Sauer 375 H&H magnum and the 300 RUM is by far the more punishing.
Here's the part that was amazing. One hundred yard 3 shot groups off of sand bags were consistently within 1/4 inch of being one inch. By that I mean some groups were slightly under one inch, some slightly over an inch by about 1/4 inch. Considering the aggressive hold I had to take to control the rifle under recoil I was amazed. I am using a Zeiss conquest 3-9 scope with QD mounts. Neither one of us could believe it. My friend never did reload for his. He didn't think he could improve on what was already there with factory loads. I do and I use an assortment of bullets including the partitions along with RL-25 powder. I'm not shooting any better but I am shooting cheaper.

December 29, 2008, 11:27 PM
i really like the rum series of chamberings, and i think the 300 rum is the best of the bunch.

that said, for your stated purposes, i really think you should look at the 7 rem mag, and go from there. the 300 rum, especially in a sendero, is a specialty piece. one that i like very much, but one that may be too much of a niche piece for what your purposes are at the moment.

December 30, 2008, 11:24 AM
I too have a .300RUM. It's in a Savage M110.

Accuracy is about what was related above. I have gotten some 3-shot groups that were tighter, but overall, the rifle is about 1moa with good bullets. It really liked a box of Remington 200gr Nosler Part. I recieved with the gun when I bought it used. I got it for $225 as nobody wanted anything to do with it due to cost of ammo. It's also equally accurate with the 180gr Nosler Part. Remington factory load. I bought a box at Walmart. It'd been marked down from ~44.00 to $8.00. It didn't sell ! I shot 3rds to check POI with my present zero. I still have the rest in case they clone Wooly Mammoths..........

Recoil is subjective. Mine had a 1/2" butt pad, and with the pencil thin 26" bbl, recoil was annoying in that from field positions, it'll draw blood with the famous "Weatherby" eye........ Even with a rubber coated scope objective.
I cut the stock to fit me, and put a "Kick-eez" recoil pad on it. It's tolerable now.
Recoil can be summed as about like a Remington M870 with a 3" magnum turkey load. Not untolerable, but not fun, either. However, this rifle is "light" for what it is, at about 8.25lbs. (Wears a Simmons Mag44 3.5-10X scope).

If you reload, by all means get the .300RUM. I'm using surplus WC-860 from .50BMG pull downs. I paid $50 for 16lbs. It's going for about $60 for 8lbs now. It cost me less to shoot this rifle than a .30/06 or .257Robts using current cannister powders. I've got a "reduced" recoil load of a 165gr Nosler BT over the starting load of IMR7828 that is sub-moa accurate and gives 3,100fps, or about like a .300WinMag factory load.

However, for most purposes its "over-the-top" too much rifle. But thats what makes it "interesting".

I do enjoy the notice and notoriety I get at the range when I touch it off!
But, a cut eye for "blasting" a whitetail doe is a bit of a large price to pay!

December 30, 2008, 11:43 PM

Thanks for the info on the loads. I'm not, currently reloading, but I'm about to get back into that as well. A lot has changed in the last 20+ years in terms of powders and bullets available and I've forgotten a lot. When I was a kid I had a competitive shooter for a dad and was surrounded by some of the top shooters in the country to pick their brains- those resources have all passed away; so, I'm do some remedial research before I jump back into the reloading game- no sense in wasting time and money and most of all I want to be safe.

I'm really not too worried about recoil as I grew up shooting big guns all the time. I was 13 or 14 when I started shooting my .375 H&H and around that time I did a little shooting with my uncle's double rifles (.416 R & 500 NE if I remember right) from Africa. My dad didn't tolerate fear of recoil very well and worked with me until I grew accustomed to it. Plus, he enjoyed placing bets with club members on whether his kid could shoot a big gun repeatedly and accurately or whether I could outshoot another member, LOL! I'll tell you, the ONLY gun that ever gave me a "scope track" was my grandfather's 7mm Weatherby- that gun gave me a cut that left a scar that's still slightly visible. The gun just didn't fit me and it had a lot of muzzle rise that I hadn't experienced with Winchesters I was accustomed to. It's the only gun that ever gave me a serious flinch and it took a lot of work to get past that.

I know EXACTLY what you mean about the looks you get when you touch off a round from a big gun at the local range- it kinda stops the action cold and draws people over to watch. Especially when it's a kid doing the shooting. I'm sure no kid anymore, but I still love to watch the looks on people's faces! HAHA!!

Thanks for all the input fellas! I'm still undecided, though. Let me ask y'all this. Do you think I'd be better off buying 2 rifles to cover my bases. I'm beginning to wonder whether I should consider buying a .270 or a .308 for the smaller end and a 300 Win Mag or a 300 RUM for the big end. Or, would there be too much overlap between the two rifles, no matter which combination I chose?

If you think getting two rifles to cover the gambit would be a good idea, let me know which combination (from the calibers I just mentioned) you'd suggest and why.

Thanks y'all!


December 30, 2008, 11:53 PM
Based on this statement -
I'm just getting back into shooting rifles after a 15-year hiatus
I'd say the .308 would be a better option. When you get bored with that, then get the RUM. Of course there is some overlap, but enough difference that having both in the end would not be overkill.

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