300 RUM, 230 Berger, Retumbo load

[jmden]

What's your 300 RUM, 230g OTM Berger, Retumbo load?

Just now ready to start doing load development. Did a quick search that didn't turn up anything, but I know it's here, so sorry to start another thread.

If I recall from doing a little looking into this some time ago, I thought I would probably start at about 89-90g of Retumbo and work up.

This rifle shoots 210 VLDs comfortably at 2993 fps and 94.7g Retumbo, just for reference.

Thanks!

Jon

 

[jmden]

Anyone?

 

[Franklin]

Hodgdon shows 89gr as a max load for a 220gr bullet and 84 for a starting load. I don't think I'd start at 89 if I were you.

 

[jmden]

Hodgdon shows 89gr as a max load for a 220gr bullet and 84 for a starting load. I don't think I'd start at 89 if I were you.

Yes, that's why I'm working on getting an idea of what others are using for a load. However, at nearly a 6g drop from my quite comfortably below max 210g VLD load, I would think that 89g might be an OK place to check for pressure, but I certainly want to see what Retumbo loads folks are using before I load some up for initial testing.

Keep it coming...

I did find this thread with some more searching:

http://www.longrangehunting.com/forums/f28/230-bergers-300-rum-86425/

It has quite a bit of good info with some guys at 87 or 88 grains of Retumbo, so it's likely I should start perhaps even at 86g, but with 86g being nearly 9g lower than a comfortable load for 210s in my rifle and a nearly identical bearing surface length between the 210 VLD and the 230 Hybrid OTM, a 9 grain drop seems like quite a bit to me, but it may not be.

 

[jmden]

About 2745 fps at 89g was all I could get out of this rifle. Switching to 215s...

 

[brentc]

That's surprising, considering I can drive the 230 at 2800 fps with 75.5 grains of Retumbo in a 300 Win mag.

I believe you could drive them harder. Did you try pushing past 89 grains? If you're pushing the 210s with 94.7 grains, I'd say you're 230 load should be approximately 2 grains less powder. One of the trends I've seen while reloading, and it happens often, is that your powder charge and bullet weight has a 10 to 1 inverse relationship. For every 1.0 grain of bullet weight increased or decreased. The powder charge is inversely adjusted by .1 grain.

For instance if you want to increase your bullet weight 20 grains, your load should fall in at around 2 grains less powder. The same rules apply though, work up carefully.

 

[jmden]

Was getting pretty good ejector pin marks at 89g, so I did not see much point in going further. I just think Retumbo is too fast. I'd used US 869 with this class bullet before but found it too temp sensitive.

 

[RLA]

Jmden, Have you tried H1000?

 

[brentc]

Was getting pretty good ejector pin marks at 89g, so I did not see much point in going further. I just think Retumbo is too fast. I'd used US 869 with this class bullet before but found it too temp sensitive.

I think you may be on to something here. At first glance it might be hard to believe that Retumbo is too fast for the 230 combo in the RUM, but it might just be what is going on. If this is truly the issue, the 215s would definitely work better. H50BMG might be the extreme powder you need for a 230 load.

 

[Gongbanger]

I am using 87.5 grains of Retumbo w/ the 230 OTM . Getting 2875 f.p.s out of a 26" barreled Montana rifle company 300 RUM. Dialing 22.5 MOA to get 1000 yards.
Still has 1700 ft/lbs. energy @ 1000 yards !
Have shot a couple of mule deer @ over 500 yards w/ this set up & it really flattens them out! Ready for Oryx or Elk. E mailed Berger & they said this bullet was a thicker jacket than the hunting VLD yet not recommended for hunting as it had not been proven yet. They did say that a 230 hunting VLD was in the works ?