what kind of velocity you getting out of your 338 ultra mag

I haven't done a lot of reloading in mine yet but have settled on one load with retumbo and 225gr accubond at 3140fps.

They say those 225 Nosler Partitions will go 3225 with RL25

Using Retumbo powder and Hodgdon Data 2 grs. below there listed max. MY 700 Rem with a 26" barrel averaged 3060 fps with a 250 Partion. There was no sign of pressure but that seemed a little quick so I backed off till I was right at 3000 fps. My favorite load is H1000 and a 210 Partion at 3170. I just got some 200 Accubonds I can't wait to try them. good hunting KH

KHH,

I have noticed that Retumbo is slow to show pressure signs in the 338 Ultra as well.
I think you are right though...At 3050fps there is bound to be some pressure. Rl-25 also tops out at just over 3000 but there is no doubt about the pressure.

I get 3270 out of the 225 Nosler with 98 grains of RL-25. This load is hot but has proven accurate and safe in several guns (work up slowly).

X-man , I have some RL25 on hand but haven't tried it yet. For me RL22 has always given top velocity but by my own testing it really is affected by temperature . I'm not sure how much differents it makes in the real world but from 75 degrees to 15 degrees by chrono it averaged 132 fps difference in my 300 Win. Because I hunt in extremely cold weather , many time below zero, I use Hodgdon extreme powders. I'm really interested in the velocity your getting out of the 225's. I worked with 200gr. Accubonds and H1000 this week. Velocity is topping out at 3180 only about 10 ft. velocity spreads groups are real good , well under 1". I'm thinking H1000 might be a little to slow for that bullet. I really was thinking 3200+ should be there for either the 210 Par of the 200 Accubond. I just can't seeem to get it there.I don't plan on messing with the load just because it shoots so well . I have heard Ramshot is pretty temp. stable so I may try some of that.Good hunting KH

KHH,

Rl-25 isn't necessarily a better suited powder than is Retumbo, I was only stating my experience for "ho" and others curious as to the Ultra's capabilities.

I find Rl-25 to be a bit twitchy pressure wise in the 338 Ultra. I have also seen 50+ fps variation between different cans and a good friend experienced more than that when he took a shot at a moose...Got the moose but stuck his bolt shut. Now he understands why I don't buy one pound at a time and why we need to be careful with a new lot of powder.

For me H-1000 always seemed a little slow velocity wise (give it's burn rate).

Rl-22 and 25 will make the 210 go fast but that does not help you. Imr-7828 may be worth a look as may H-4831. Both are very effective in the 340wby.

All that said the 225 Nosler or TSX (or bigger ) are probably better suited to the Ultra than the 210.
We (my shooting buddies and I) have been playing with Retumbo and the 225 Barnes TSX. I shot sub moa groups last winter (during a heavy snowfall) then shot better groups in the summer (75 degrees) following with the same load. You would have to be more scientific to calculate any velocity difference.

The loaded velocity was 3100 but this load will go faster.

Jamie