I think I found a load! 300 ultra and retumbo 180 gr bt

nitis · Mar 14, 2010

So took my plain old 300rum sps out today to start trying to find a load using 180 gr ballistic tips. I was only shooting at 50 yards as I dont have a real high poser scope and I was out to try about 8 different loads so I could find a starting point.

Anyway it looks like 99 grs of retumbo gets the nod I was worried when 97 was not very good but it seems like the harder you push this gun the tighter the group I had 4 shots making one ragged hole. I may try and creep up a little just to see because I had no pressure signs and the jug of powder shows 101.5 grs for a load.

Anyone else use this combo and how hot did you go? What kinda velocity?

khh · Mar 14, 2010

I use Retumbo in my 700 Rem 300 RUM . Hodgdon lists 100.5 with a 180 gr. as max . My load is 99.0 with 180 Partions .010ish off the lands I'm right at 3300 fps , groups are right at 1" @ 100 yards. I start to get pressure at 99.5. I loaded 180 gr. Accubonds , there pretty similar to Ballistic tips , 99.0 was right at 3300 fps . I got great accuracy, but .01 off the lands the cartridge OAL was to long to fit in the magazine and when I shorten them up the accuracy deteriorated . There's not much you can't do with a 180 gr. partion @ 3300 fps. good hunting KH.

JD338 · Mar 14, 2010

Nice!
Retumbo is a great powder for the big case calibers.

JD338

DrMike · Mar 14, 2010

nitis,

It is often the case with slower powders that the faster you push the bullets the greater the accuracy. Small changes in powder charge can make some great changes in groups size, especially with the slower powders.

nitis · Mar 14, 2010

I plan on swapping over to the AccuBond once the biggest part of the load development is over and I suspect I should see little to no difference.

I may load a few at 100 and 101 just for kicks but I think I am there