IMR 4850 for a 300 RUM?
Most folks say the 300 RUM works best with the slow powders such as Retumbo, RL25, Magnum. The Nosler reloading manual has IMR 4850 as the "most accurate load tested" for quite a few of their .308 bullets.
I have found this to be true as well in my 300 RUM. IMR 4850 shoots the best so far. I don't have a chrony, but I know the bullet is much slower than is capable. 3200 fps or more seems standard with a 180 grain bullet. I am shooting 80.4 grs with a 180 gr swift scirroco 2 from factory REM 700. I am under 1 inch MOA at 100 yrds. The swift data suggests about 3100 fps or less.
I would love to try the Nosler 180 and 200 gr accubond bullets, but I can not find them (sound like a broken record). Maybe I could eek out some more velocity with the Noslers vs. the Swift bullets.
My questions are:
Does anybody have the same experience with IMR 4850 and the 300 RUM?
Has anybody seen much difference between the 180 gr. accubond and scirroco2 in regards to velocity, accuracy and performance on game?
Then again, 3100 fps is pretty darn fast. Maybe I should just be satisfied with a Really fast instead of Ludicrous fast. And the recoil sucks no matter what load I use.
I just picked up a 300 RUM and plan on trying Retumbo and H1000 in it. You should be getting 3200 with a 200 gr bullet and 3300-3400 with a 180 gr bullet and good accuracy if it's an accurate rifle.
If you're satisifed with 3100 with a 180 gr bullet, you might think about a 300 WSM. I'm guessing your RUM is a 26" barrel and if you pushed a 180 gr bullet in front of about 67 gr or so of RL17 out of a 300 WSM with a 26 barrel, I'm betting you could come real close to 3100 fps and maybe faster. And everything about the WSM is way cheaper than the RUM and just as accurate, maybe more so.
Sorry fior getting a little off your question, but something you might think about. The reason I got a RUM was for speed.
Good point about the 300WSM. It was a tough call what to buy. No use getting yet another .30 cal gun (not for me anyway).
I did some more digging into published data. I have the Nosler manual and now the 300 RUM Loadbook USA manual with all sorts of data.
I found 2 sources that used data for the Swift Scirroco 2 180 gr bullet with IMR 4850. Swift has a max load of 82 grains for 3129 fps. IMR data has a max load of 79 grains for 3070 fps. My loads have had pressure signs over 82 grains, and they did not shoot well. According to the IMR data I should be well into my maximum, and likely shooting over 3100fps. According to Swift data I have a ways to go and am likely shooting under 3100 fps.
Just to throw a small curve ball, you can look at the Nosler data for a 180 gr bullet. They have an 82 gr max at 3187 fps, close to the Swift data. They have and accurate load of 80 grains 3125 fps, consistent with my loads and hence the topic of my thread.
I am intrigued with velocities over 3300fps for 180 gr bullets. Most of the data I have puts most bullets below that velocity and not close to 3400 (yeoww, that is fast). The exception is with the Barnes bullets. They seem to be about 100fps faster on average. I have some on order and will be trying them out after a short spring bear hunt.
I guess I need to buy YET ANOTHER piece of equipment, a chrony.
Yup, I would definitely suggest a chrony. When it comes to the RUM cartridges (except the 375), you are not likely to find real good manual data on velocities. RUMS are best shot through 26" or longer barrels to get efficient powder burn. I believe most of the manual data is based on 24" inch barrels which will show much less velocity than a 26" barrel. 3200 fps is about average for the 200 AB in front of about 95 gr Retumbo in a 26" barrel. If Retumbo doesn't work well for you you might try H1000. In any case, it would be a good idea to chrony your IMR 4850 to see just what it is giving you.
I have essentially the equivalent of the 300 RUM - in fact the cartridge that the 300 RUM is based on - 300 Canadian (which of course is based on the 404 Jeffery). Nevertheless, I have been reloading for it for 10+ years and chrono all my shooting. The best powder for my rifle (24" barrel) is either RL 22, RL 25, Magnum, or IMR 7828. For the last several years I have been using a favorite load with RL 25/180 gr Barnes that although rather slow at 3250 to 3300 ftp is CONSISTENTLY very accurate. 3100 to 3150 is my "go to load" in a very light 300 WM, 24" tube, with 180 gr. Barnes. Rifles are like women - every one is different and what you see is not always what you get!
DUH, yea I mean 4350. That is what happens when you type late at night.
I've been loading the 300 rum for a while now.
Retumbo for 165-200 grain bullets has worked best for me.
H870 will beat retumbo by a little with 200 grain bullets if you can find it.
Use a premium bullet.