300 RUM Load?

[jmden]

Has anybody done any loading for the 300 RUM with AA8700 with 200g bullet? Results?

Thanks

 

[sakofan]

Try RL25 with that RUM...sakofan...Or maybe RETUMBO.

 

[JSweet]

Its not exactly what you asked, but!
I've had good luck with Retumbo with the
heavier bullets, 180,190,200.
H-1000 with the lighter ones 150, 125gr.
Moves them out lickety-split, and group about 1 moa@100yds. or better.

JSweet.

 

[jmden]

Thanks, sakofan and JS/NH. I think my most accurate load nearest the speed I want will be about 94 grains of RL 25 with the 200g A-frame at about 3075fps. Not quite the speed I was hoping for (3150fps). Getting extractor marks on every other case or so at 96.5g RL25 at about 3170fps on average This is a stock Rem. 700 in LSS.

I see some folks are getting closer to 3200 fps with the 200g Accubond. Might look at that as it seems like a good bullet and I've not been impressed with the A-frame in terms of uniformity, especially considering the cost.

I'm not real experienced here but it seems to me that a 200g bullet out of the 300 RUM needs a slower powder than RL25 to optimize the case potential? The Accurate Arms manual using AA8700 at max 111. g with the 200 A-frame shos 3115fps, but that's compressed they say, although not too awful much when I stuck a 200g A-frame in a fireformed, neck-sized case with an OAL of 3.677 to fit in the magazine. H870 seems like it would be good, but it's no more... WCC-860?? Trying to find the magic powder to take advantage of this big case for this overbore chambering and a 200g bullet.

Thanks for your help.

[ 11-08-2003: Message edited by: Jon Denham ]

 

[Brent]

Jon,

You've hit the nail on the head. H50BMG might be worth a try. H870, like the WC872 is probably too temp sensitive for me to invest time with, so I don't use it. Retumbo and RL25 have worked good with the 200gr Accubond in my Ultra, and the 30/338 Lapua Imp too. I got about 3100 fps with both, but pressure on the case head was higher with Retumbo at that speed for some reason. The Oehler M43 indicated Retumbo's pressure was actually 4000 PSI lower though. Excess pressure signs with Retumbo come on earlier for some unknown reason, it's the only powder I've seen that with. Accuracy has been nothing but great with it so far tho.

 

[Mysticplayer]

Jon, I am working up my 300Ultra mag and can offer some advice. With H870, the load is around 100gr w/ the Accubond. With 240gr MK, the load is 98gr. All this in my rifle which has a long throat. Use with care.

I have found that these ball powders, although very cheap, can be a pain due to being temp sensitive. For fall/spring shooting, they should work just fine but forget about using them in the hot sun unless you are willing to adjust loads on site.

I have now experimented with H50BMG and my rifle seems to really like it. Being a new generation powder, it is temp insensitive and should work well throughout the year. Yes, much more expensive but shooting these cannons is not cheap to begin with. I would rather spend a few more bucks per box and hit at long range then not. Want to get some vel numbers on this powder and 240gr MK. Hopefully, it is faster.

Jerry

 

[Brent]

It's strange you should ask if Remingtons brass is soft. I can tell it's soft in my Ultra, but really it's not too bad, it could be worse.
Example;
I was at the range yesterday and a guy I know that works at a local gunshop was shooting his 300 SAUM. You should have seen the cases that were coming out of that thing!!

The case head had ejector marks on every one of them. On a scale of 1-10 the marks were about 3-5, with 1 being ever so slightly noticable and 10 would be brass is extruded to the point that the stamping is no longer even visable under the ejector mark.

What was amazing to me, as I've not ever seen brass do this before but, brass actually flowed out into the "extractor" groove right next to the ejector button in the rmainder of the unfilled extractor slot. When ejected, it tore part of this extruded edge off, but plenty remained mashed out past the original case head diameter. In my opinion, these cases were basically trashed now.

This was Remington factory ammo loaded with the new bonded core 150gr Core Lockt Ultra!

He fired them over my Oehler M43 to see if MV was possible way high, indicating high pressure.

MV were:
3020
3031
2976
3066
2974
2992

ES = 92
AVE= 3010

Believe it or not, this load grouped under 2.5" at 300 yards every "5" shot group. He fired them fast too. The rifle was one of the new Remingtons with the camo stocks, with a light weight SS bbl, not sure what length, 24" I think.

...

My friend Charlie has a 338 Ultra and he's used three different lots of brass and they all show ejector marks and stiff bolt lift with medium loads, and he can't get published MV's with it either. I would have to guess both of these guys has brass that is SOFT, as MV's were lower than expected on both rifles with factory loads, and only medium charge weights with the other rifle.

I think my 300 Ultra brass may be a bit better than what's mentioned above, thankfully. It may be all the 300 Ultra stuff is better. My dad is wanting to have his 30 cal AR-30 chambered in 300/338 Ultra, as the 338 Ultra brass is just short enough to fit in the magazine where as the 300 Ultra brass is too long at the shoulder. He don't want to anneal, so he doesn't want to pay for 338 Lapua brass and not get the life out of it, and grinding a 300 Ultra FL bushing die shorter would be an easy and inexpensive solution.

 

[jmden]

Brent,

That is some interesting data you collected there. I sure wouldn't expect a 150g bullet going at that speed out of that chambering to have pressure signs. I wonder what's up?

Jerry, What load are you using with the H50BMG?

Thanks,

Jon Denham

 

[jmden]

Brent and Jerry,

Thanks for the info. I'm heading to MT in a couple of days for 2 weeks of elk hunting and due to lack of time, I've settled on 94.4g of RL25 with a 200g A-frame at about 3097fps over the Oehler 33. Got it zeroed at 300. Should kill an elk just fine, I thinks. I still get faint extractor marks about every other case with this load even, but I'm out of time. Will have to do for this hunt. Is Remington brass soft????

I did something I don't usually do yesterday at the range as my curiousity got the best of me. I has seen that Accurate Arms has AA8700 at a max load with the 200g A-frame at 111.0g at 3115fps. So, I loaded this in just one round--curiosity got the best of me and I didn't have time to do any more load development. Wow! 3280 fps, but with sticky bolt lift (which I've never felt before in the two rifles I load for the other being a .30-.338)and obvious extractor mark. Stupid--shouldn't have done it. But now I know. I hope to play with AA8700 (Jerry, I guess you'd call this a ball powder, and I don't know if it is "modern powder temperature insensitive" or not. Do you?) and 200g Accubonds later.

Also stuck 95g of RETUMBO in a case with same bullet and it had an extractor mark at 3033fps. Not what I had hoped.

BTW, I got a Redding neck sizer die (for $30, I figured I'd like to see if I could do that with the 300RUM) and this rifle seems to be accepting the neck size cases multiple times just fine. Seems to have fine accuracy if I do "my part". Any similar experiences?

Thanks,

Jon Denham