.300 Remington Ultra Mag

TBASTIAN

Handloader
Jul 1, 2006
372
1
Any suggestions for pet loads in the .300 Remington Ultra Mag? I just picked up a new Model 700 today and am interested in loading the 180 grain Partition, and the 180 grain Barnes TTSX.

I loaded a bunch of 165 grain Partitions with 96.0 grains of H-1000 for sighting it in tomorrow. I'm excited to see how she shoots. I've always owned Brownings and Weatherbys, so I'll be interested to see how the Remington shoots!

Thanks in advance.
-TB
 
Work up slowly from 93 to 99 gr of Retumbo for the 168 to 180 gr.
 
my go to bullet is the 168gr TSX with retumbo for 3270fps. ITs well below max and kills everything I have shot with it very well. Accuracy is outstanding and the performance on game is extremely impressive. The 180gr AccuBond is another good one expesially if your main game is whitetails. You just can't beat the RUMs for accuracy and super performance.
 
Mine has shot most powders what I'd call decent - not great.

Out of all the big name powerders - RL-25, H-1000, Retumbo etc etc I've found IMR-7828 the most pleasant to shoot
out of the RUM coupled with the 180gr AB's
 
A very often recommended load is working up to Hodgdon's load of 95 grains Retumbo under a 200 gr Nosler AccuBond.

All sorts of outstanding results have been reported with that combination. You can expect at least 3,000 fps, and more likely 3050 - 3100 fps based on what I saw with my .300 RUM. The 200 gr bullet is a natural for the big case capacity as well. Sadly, I never took any game with the combo, but it sure performed well on the range.

Best of luck, Guy
 
Guy Miner":1ddlojl4 said:
A very often recommended load is working up to Hodgdon's load of 95 grains Retumbo under a 200 gr Nosler AccuBond.

All sorts of outstanding results have been reported with that combination. You can expect at least 3,000 fps, and more likely 3050 - 3100 fps based on what I saw with my .300 RUM. The 200 gr bullet is a natural for the big case capacity as well. Sadly, I never took any game with the combo, but it sure performed well on the range.

Best of luck, Guy

+1 on the 95gns of Retumbo and the 200gn AccuBond. I use this load with Fed GM215M primers. I'm getting an average of 3137fps with mine. I've take a CA hog (292 yrd shot) and a spike elk (175 yd shot). Both were bang flops.
 
My Load for 300 Ultra Mag:

New Remington Cases
Federal 215 Mag Primer
180 AccuBond
96.1- RL 25 Powder
26" Barrel Magna Ported
Remington 700 BDL

This load is absolute Max. Developed in 85-Degree Temp. here in the South, no pressure issues. Load chronographed at 3372fps. Cuts Holes at 100 yards.
I have had very good results with Retumbo as well shooting 97-98 grains of powder getting 3380-3385 fps. also cuts holes with the same Bullet.

I must caution you, with the above loads I cannot use re-sized brass due to pressures, but it does work with new brass. I will be reducing these loads this winter to better utilize the stock pile of brass I have. I have shot this way for years, have determined the expense for brass and additional speed gained isn't worth it. Besides an Elk/ Deer wouldn't notice the difference in all that speed, it's just DEAD! I believe I can back this load down to 3300 fps and have the ability to use my re-sized brass. Good luck with the load development.

Don
 
Guy Miner":cjyrfsv7 said:
A very often recommended load is working up to Hodgdon's load of 95 grains Retumbo under a 200 gr Nosler AccuBond.

All sorts of outstanding results have been reported with that combination. You can expect at least 3,000 fps, and more likely 3050 - 3100 fps based on what I saw with my .300 RUM. The 200 gr bullet is a natural for the big case capacity as well. Sadly, I never took any game with the combo, but it sure performed well on the range.

Best of luck, Guy


Yup that is my loas with the 200 also.

92 gr of rl 25 works well with the 200 Ab as well.
 
Thanks for the information guys.

Returned from the range this afternoon pretty happy. The 96.0 grains of H-1000 and 165 grain Partitions did pretty well. Especially, out of a gun that hadn't been broken in yet. After initial sight-in I shot two three shot groups. The first measured 0.87" and the second measured 1.09".

Ordered some 180 grain TTSX's from Graf & Sons today...looking forward to trying them out as soon as they arrive.
 
Sounds like a usable load to me, have fun messing around with the other loads.

Don
 
i know thw 168 ttsx is not the best weight bullet for the 300 rum but 93.6 gr of reloader 25 behind it turned 3 rem 700 into .50" shooter's for us
velocity is not great at 3200 but accuracy is impressive to say the least worst groups with 1 of the 3 rifle was .60" best are a few groups in .25" (3 shots)
 
Man, that 300RUM is a monster! Hard to go wrong with a 200gr Pt or AB at 3100+! Scotty
 
hardpan":2jxtwmw1 said:
i am using 87.5 gr of imr 7828 behind a 180 gr Partition and AB. Both shoot sub 0.5" at 100 yds.
Hardpan
I have used this load also and it is easy on the shoulder plus it is really accurate! Kind of a shame to load this monster down to 3150 fps with the 180 though. Funny thing is, the guy I loaded these for also has a 300 SAUM that I worked up loads for also and he uses the short mag over the big gun. When you carry the 300 Ultra cartridges on a buttstock shell holder the gun gets heavy! Retumbo was not available here when I did the big 300. I think to justify having it, 200's and retumbo would be the way to go at 3200 fps.
 
TBASTIAN

Nice shooting! Keep us posted on your load development with the big 300 RUM.

JD338
 
Finally had a chance to put together some loads...Will be trying out 5 different loads with H-1000, Retumbo and IMR 4350 tomorrow. Loaded some 180 grain Partitions and TTSX's. Will be re-checking an earlier load with 91.0 grains of H-1000 and the 180 TTSX, it was shooting 0.95" earlier...hoping to tighten it up a bit. Will post some pictures upon my return!
 
Made it out into the mountains today to check my loads...definitely not the results I had hoped for, so it looks like I'll be trying some additional loads. Here are the results from the day:

180 Grain Nosler Partition
H-1000 94.0 grains - 1.89" Two touching with a third shot high.
Retumbo 97.0 grains - 1.64"
IMR 4350 80.0 grains - 1.34"

180 Grain Barnes Tipped TSX
H-1000 91.0 grains - 1.275" average (first group 0.95" - second group 1.60")
Retumbo 93.0 grains - 1.48"

For those of you loading the .300 RUM with 180 grain pills, what is your OAL for the loaded cartridge? Thanks in advance!
 
What COL/OAL did you use? I went with 3.635" for my 180AB and 200AB loads. My 180AB load was 98.5gns of Retumbo.
 
Have you checked this rifle to see if the barrel is free floated? Also I would bed the rifle and remove the pressure point then start my load data. I have found the 300RUM to be a highly accurate round when the right combo is found. Dont give up. Maybe loading a few different powder charges of the same powder and bullet combo. Seems like the H1000 and TTSX load showed promise. Maybe a simple OAL change or .5 or 1 gr more or less powder might tighten it right up. Let us know how it goes. Good luck.
 
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