.300 Rem Ultra Mag - report

Talk about North American big game hunting.
Guy M
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Location: Washington state

.300 Rem Ultra Mag - report

Post by Guy M »

Picked up a good looking Rem 700 CDL in .300 RUM, spring of 2006. It was just too good a deal to pass up. Great looking rifle, with a trigger that needed attention. It sat around for a while, while I gathered the supplies needed to load it, along with data, from all the usual sources as well as informed users.

This is a really big case... No belt. Rebated head. It appears to make maximum use of a Remington long action. Huge appetite for powder, and has the ability to toss heavy bullets pretty darned fast. Tried some Remington factory loads first, 200 grain Nosler Partitions. Over my CED Millenium chronograph they averaged 3190 fps, with a few topping 3200 fps. I can live with a .30 cal, 200 grain premium bullet at 3200 fps... :shock: Accuracy was okay, but nothing to write home about. Despite the 26" barrel, this is a sporter-weight rifle, not a heavy bench rig. Recoil is substantial. The CDL stock design helps as does the very nice Limbsaver recoil pad installed by Remington. I adjusted the trigger to a nice crisp letoff, and installed a 6x Leupold in dual-dovetail rings. The rifle has not been bedded. The stock appears to have two crossbolts.

Started handloading with standard RCBS dies. Priming the big case was interesting, because it doesn't fit in a standard Lee Auto Prime, without modification. Rather than carve up my Auto Prime, I bought the RCBS primer tool, pretty nice piece of gear although we had our teething problems.

Based largely on what I'd been told by others who've loaded the .300 RUM, I selected the following components: Rem magnum primers, Hodgdon Retumbo powder, Sierra 200 gr SPBT bullets, Nosler 200 gr Partition bullets and 200 gr Accubonds. So far I've only loaded the 200 gr Sierras.

I've gone up to 95 grains of Retumbo - which is nearing the max from Hodgdon's data. My handloads have broken 3100 fps, with a 200 grain bullet without any excess pressure signs. At 94 grains of Retumbo I'm seeing an average of right about 3050 fps, and three shot/100 yard groups are amazing to me... Often I'll get two bullet holes actually touching, and the third not far removed. I don't shoot it more than three shots at a time. The slim sporter barrel gets hot in a hurry, burning 94 grains of powder at a shot, and I need a break too.

I am considering a muzzle brake for this rifle. Haven't had one in the past, but have shot a few braked rifles - and they do indeed tame the kick of powerful magnums. Also considering a good laminate stock, as this rifle is destined for some high-country hunting in rough conditions and rough weather. I didn't hunt with it last year, as I hadn't gotten very far along in load development, but this year I suspect it will be my primary rifle for black bear, elk and even mule deer. It's a thumper on both ends, but accurate and easy handling.

Regards, Guy
Mike
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Post by Mike »

Nice write-up, Guy. I've got a brake on my Browning .300 Win Mag and wouldn't have it any other way. That gun is quite tame compared to a friend's Ruger .270 with their skeletonized synthetic stock. That gun kicks like a mule (for a .270).
Ryan S Albright
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Re: .300 Rem Ultra Mag - report

Post by Ryan S Albright »

Thanks for the write up! It is good to know. I have been surprized by how accurate the magnums can be my friends 338 could be used on squirrels and I have used my brothers 7mm rem mag on squirrels both these rifles will put three bullet touching at 100yrds. happy hunting let us know how the bullets preform on the game you are hunting.
jayph
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Re: .300 Rem Ultra Mag - report

Post by jayph »

My uncle bought a similar gun (remington LSS). He breaked it with a vias and it's about on par with his featherlight 30-06 pushing 180gr. He also had a premium recoil pad (lims I think) installed. It's not bad at all to shoot and the vias is alot quieter than the breaks I am use to when standing beside and alittle behind. Plus he can carry his all day being a sporter rifle like yours. you could look on ebay if you want a laminate stock as I see take offs from the LSS and they sometimes go cheap.
skipper
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Re: .300 Rem Ultra Mag - report

Post by skipper »

Guy M

I've got a couple of 375 H&H magnums that have a huge appetite for powder also. I would highly recommend installing a mercury recoil reducer (or two) to tame that 300 Ultra Mag. My Winchester Model 70 375 H&H Magnum also has a muzzle brake. This really reduces the recoil but will almost break your ear drums. The muzzle break idea is a good one but it comes with a price. If you go on a guided hunt, a lot of guides will not take you with the muzzle brake. Hunting with ear plugs or electronic sound damping ear muffs is the pits. You might want to have your muzzle brake installed with an optional end cap for when you remove the brake. The end cap is mostly to keep you from damaging the threads on the end of the barrel, but it also serves as a crown. With a mercury recoil reducer and muzzle brake, you will still have some damping when the situation requires you to remove the brake. The mercury recoil reducer will tame the recoil to more of a push than a sharp whack to the shoulder.

You know, I never feel the recoil when I'm pulling the trigger on a game animal. Too much adrenalin, I guess.
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Guy M
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Joined: Sun Mar 11, 2007 11:58 am
Location: Washington state

Re: .300 Rem Ultra Mag - report

Post by Guy M »

Interestingly enough - I ended up selling that .300 RUM off and buying a very accurate .300 WSM that is more to my liking.

Still have a tremendous respect for the .300 RUM though - it's one heck of a long-range cartridge. More cartridge than I needed or wanted I guess.

Regards, Guy
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