Has anyone reloaded a 300 Remington Ultra Mag with IMR 4350 powder? I know it burns a little faster than some of the preferred powders (i.e. 7828), but I'm wondering what kind of performace it has with 180gr Nosler Partitions. I've got about 12lbs of 4350, so that's why I'm leaning towards that powder.

I just shot my gub today, the best loads I had shot was imr 4350 89 grains with a 150 nos bal tip. All shots touching. Stupid accurate. The 7828 was not consistent

jethro,

Asa rough guide and with 3000 f/s plus calibers, you will drop about 100 to 150 f/s if you use a powder that is a burning range down from what the ideal would be.

For example, in the 300 Winchester with 150s or the 270 with 110s, you will get close to full velocity with Varget. But with 180s in the 300 and 130s in the 270, you will drop about 100 to 150 with Varget.

I would guess with the 300 Ultra, you will probably be able to duplicate full 300 Wby ballistics for the 150 grain bullet if you use IMR 4350 and probably a bit better than the 300 Winchester full ballisticas with 180 grainers.

I use to shoot 300 Win a lot in bench style guns and Varget often gave me the best combination of velocity and accuracy with 150 grain bullets and I would say varget in the 300 Win would be roughly comparable to using IMR 4350 in the 300 Ultra.

One thing for sure with the 300 Ultra, whatever powder you use it will go plenty quick

Mike

IMR-4350 From 78.0 grains to 82.0 grains
Remington 9-1/2 Primer

Not the best powder for your combination, but it will work.

Don't know yet, but I'd say a slower powder would be a better choice.

I'm gonna start out with RL-22 in mine.

There are plenty of manuals out there that say a faster burning powder is more accurate. 4350 has been known to be exceptionally accurate in 300 wby with heavy bullets. Can't see why it won't work in your application. I'll take a super accurate load that's 200 fps slower any day--(that is unless we're starting with a 30-30)

I have used 4350 in my ultra with the 125gr bullet's.Velocity is a touch over 4100fps and accuracy over 5 shot's is around an inch...

Gentlemen, thanks for the responses. I'm actually getting ready to reload them now. I have a couple of factory loads (180 gr nos. part.) that I am going to chrono and use as a starting speed. The factory loads have been
surprisingly accurate for me. According to the Nosler manual, 4350 was the most accurate powder they tested. The loads seem to lean quite a bit on the conservative side compared to other manuals. Has anyone else noticed this? Their max with the 180 gr nos. part. using 4350 is 82.0 gr and only 3187 fps. I believe out of the factory they are supposed to be pushing around 3250.
I'll let you know how it turns out.

Jethro,

I used IMR 4350, 180 BT, 82 gr (Most Accurate) and have shot several small groups under 1 MOA. I have not Chronographed the load yet. I ended up using 200 gr Partition Factory ammo last month on a hunt. It shot one whole. Now I am working up a 300 WSM load for a Texas Hunt. I will be working up 200 gr 300 RUM loads with Swift-A-Frame, Trophy Bonded, and North Fork Bullets with RL25. Good Luck and let us know how your loads perform. What type of Gun are you shooting?



Good Luck

Finally got to shoot the 300 RUM using the IMR 4350 powder. I worked my way up until I started seeing pressure signs, then backed off slightly. Factory loads run about 3250 fps, but the fastest I could get with 4350 was 3183 fps using 83.5 grains. Nosler says max is 82 grains at 3187 fps ( a bit off from what I saw). Above 83.5 I started seeing slight pressure signs, so I stuck with 83.5. Accuracy remained consistent with a little tweeking to compensate for the change.
Overall, I was happy with it, but still want to meet that 3250 fps goal. I don't want to be shooting a 300 win mag. Probably won't start experimenting with other powders until after hunting season. Can't wait though.

jethro, I live in Finksburg. Where do you shoot at? I go to the county gun range, but can't use my chrono there without a huge hassle. I also shoot the 300RUM and have never tried 4350. My best luck is with 200gr bullets and H1000.