IMR 4831 for 300 Ultra Mag

bill k

New member
The IMR web site gives the Max load for a 300 Ultra Mag at 80.2 with a 200 grain partition bullet. Would 72.2g be a good starting point or should I maybe go a little higher ie. 74.0g?
 

WIN71

New member
Imr4831

That's about a 10% reduction and I would say that is plenty for any production rifle. I wish I would have had that information a few years ago. I bought a 300RUM soon after they came out and not only was there no reloading info available there was no brass. I wanted to load 180 gr. partitions so I called Nosler. They recommended two powders, IMR7828 with a starting load of 87 gr. and max of 91. The other load was RL-25 with starting load of 92gr. and max of 96. BOTH LOADS FOR 180 GR. PARTITIONS. I'm not making any loading recommendations here only giving examples of the relationship between starting and maximum loads in these two powders. It looks like they use about a 5% difference. I've been using the max loading of RL-25 for the 180 partition at average 3340 fps. I'll admit, those shot strings come from 5 shots at one sitting.
Is that the Dog Creek in the Sacto River canyon?

Ron
 

bill k

New member
Thanks for the reply Win 71.
Dog Creek is just north of Shasta Lake.
Thanks for your imput.
I've been using IMR 4350 and it's been running a bit hot. Lately I've been using 79.0 of IMR 4831 with a 180g accubond bullet. I've had really good 5 shot results, under .5.
I'm hoping with a slower burning powder in the 4831 it might bring my 200g bullets together a bit more.
Right now my 200 grain 2 shot groups are at .3 at 100 yards, but the third shot is tailing out making the group .8.
Bill
 

DAVID NANCARROW

New member
FWIW, Nosler's Fifth edition lists IMR4350 as their most accurate powder tested for the 180. 78 grains to start, most accurate at 80 grains, and 82 max. Starting speed @ 3053 and max at 3187 from a 26 inch barrel.
That's in a Federal case with Fed 215 primers seated at 3.6"

For 200 grain Partitions, they list IMR4350 as most accurate again. 77 grains being the starting load and most accurate, with 81 grains max. 2916 fps starting and 2995 max.

Can't speak to the 30 Rem Ultra, but all the load recommendations I have tried in this book have been pretty darned good for the applications I have tried.
 

WIN71

New member
Bill K

I'm not getting groups like that. Originally I bought factory ammunition to get the brass. Actually the factory with 180 partition grouped right at one inch and chronographed average 3285 which was just under published velocities. I've improved on that with handloads but not much. I don't remember the model designation but mine is a rem 700, wood, blue, with sights. It's the only rifle I have that I almost wish I had a recoil reducing brake on. I think my heavy hold may be having some effect on the group size.
I'm about as far West of Old West Gun and Loan as you are North of it.

Ron
 

bill k

New member
David, I use the Nosler book and their recommended loads are very very close to being the most accurate in all my rifles. I kept dinking with the IMR 4350 loads but could never get the performace I expected till I went to the 4831.
I was also getting some high pressure indications when I used the 4350 even at the bottom range of charges.
I've never been to that shop I might try however. My favorite all time is Huntingtons in Oroville. If you've been to both how do they compare?
Bill
 

WIN71

New member
Huntingtons

You can't beat them for supply selection, there is a large used gun turnover at Old West. I started out with RCBS in the late 60's and pretty much stuck with them, Huntingtons was a natural progression.

Ron
 
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