my 300RUM showed a definite preference for retumbo and the 216gr clinch river. For a huge case like the RUM,..go with the retumbo and don't look back. I bet once you find a good retumbo load breaking in the barrel,..you will just stay with it. I could be wrong,..my wife says I have been before.
H1000, rl25, and retumbo is where you want to stay,...but retumbo is my choice. 216gr at 3200fps (30") with a 7fps ES [img]images/icons/shocked.gif[/img]
You try to get closer to the target,..and I keep trying to get further away.
Well I thought I had settled on a bear load for my 300RUM but I recently changed the stock so I figured I better do some checking.
My old load was
200 AB OAL just clears mag
94.0 Retumbo 3050fps
Av. Velocity for 10 shots today was 3125. I don't really believe it though because I used my same drop chart as before set to 3050 and was on at 100, 500 (7.5), and 820 (17).
Today I also tried:
200 AB OAL just clears mag(lots off)
Av Vel for 10 shots today was 3129. Once again same thing, original drop chart works fine.
Nearly the same 5 shot groupings at 100 yd 3/4 to an inch but at 500 the difference started to show.
94 Retumbo did a 6 high 10 wide 5 shot group at 500. 91 RL25 did 1 3/4 x 7. I was grinning for sure.
94 Retumbo then did a 12 high by 15 wide 5 shot at 820.
RL25 load 8x11.(Didn't get as lucky as the 500 yd) But it definately has turned my attention over to the RL25 for playing a bit more.
Had a 10 shot 39 ES for the Retumbo, 28 ES for the RL25 but here again I don't have much faith in the Chrony numbers. I do however have faith in vertical bullet holes.
Another load that mine likes at 100yd is 100gr Retumbo, same primer and a 180 Btip. 3312 AV vel. Cuts holes but I have learned that don't mean much. Will have to see what she does when I stretch her legs.
I have built several 300 RUM's for customers, most of the guns I have test fired with a combo of RL-25 and 200 gr Accubond. All of the rifles were running 26 inch Hart tubes, the COAL was 3.775" ( I installed extended box mags ) FED GM215M, MAXRL-25 90-92 GR. depending on rifle, velocity 3185-3212 fps, ES 11-17 fps.
I use H1000 in my personel 300 Ultra. Hope it helps.
I ended up going with 90.5gr. This printed .62in to 1.0in 3 shot groups. The best groups always come last with this gun I think the BBL likes when there is some copper failing in it. No report on vel. the weather was crapy (rainy and cloudy)so I didn't set up the crony.