300 ultra mag reloading info

Lefty7mmstw

Well-Known Member
Joined
May 13, 2012
Messages
4,985
Location
Dakota del norte
The accuracy was not good. The SD and ES were not good. I tried 5.0 grs. below max and above. Never got pressure signs. I was up to 98.0 grs. RL33. 95.0 grs. Retumbo. Couldn't get to happen. Tried H1000 . Right off the bat good. So far up to 95.0. On the other hand. Hornady 200 ELDX with 100.0 grs. RL33 was accurate and no pressure signs. 212 Eldx was good also. I stumbled on to a load with promise. 91.0 grs. Retumbo with Berger 210 VLD. Low pressure . Trying hotter.
All loads were with Rem. cases and Fed.215 match primers .025 off . Have factory magazine .
rl33 is an odd duck to be sure, but if you run it with a heavy (I run 225 hdy hpbt's) and do NOT push it that hard (some guys were over 100 gr with a 225-230 and wondering why they got shiners in hot weather) you will have a fine powder in a 300rum. Both of my 300rum rifles are running 95 rl33 in rp brass with the 225 hdy and getting 3,000 fps and .5 to .6 moa...
The way powder is right now rl50 or h50BMG might actually be a better choice for 200+ grain pills in a 300 rum. I can go to moderate compression with rl50 and be around 3K fps also-- prolly 100-102 gr in rp brass with a 220-225- start 10% low on this one though and work up.
 

Lefty7mmstw

Well-Known Member
Joined
May 13, 2012
Messages
4,985
Location
Dakota del norte
I bought a lot of factory ammo when it started to fall out of favor and some one was trying to dump it and it's not a prairie dog so I still have some left. I haven't reloaded it for years. I was on an elk hunt in January and I helped field dress a cow shot with a Barnes .300 RUM 180gr. TSX. I was impressed with the wound channel. I looked it up and found some at really good prices. I didn't buy any, but at that price, I if I needed some, I would have gotten it. If you shop around, you can find ammo for not much more than reloading. I'm a die hard reloader, but if I can find quality ammo that cheap, I'll try it. Oh by the way, my last reloads were with AA 8700. Good luck finding some.
wc 872 acts about the same to me as aa8700, as does us869... I've only got a few # of aa8700 left but I don't use much anymore.
 

Recent Posts

Top