Magpro 300 WM

[grizzly63]

Bought some of this stuff to try in the 6.5 x 300, 257 WBY and the 300 Winnie. Loaded up some in the 300 WM 79.7 -- 81.2 behind some 208 AMAX. This Sendero has a long throat so I had put a Wyatts extended mag well in the gun. Bullet coal was 3.705. 80.7 was the tightest group .75 MOA. Interesting thing was the speed was 2955. I had worked up a load using same bullets but Norma 204 powder. I chrono'd one of those today as well. 300 fps slower than the Magpro. It was about 10 F when I was shooting. Might give this a whirl behind those 225 ELDM's.
The powder worked well in the 6.5 and 257 as well. YMMV

 

[Buckbrush]

I like magpro for my 270wsm. Haven't done any testing with the 300 win or my 270 win.
I've had great results with H4831 in my 300 win and 200gr bullets also like H1000 in 300 win. I don't hunt with my 300 just because it's over 8 pounds. Mostly my long range rig Weatherby vanguard 2
Picked it up on sale at sportsman's for 450 I think. I'm only running at 2700fps and I don't think theirs a critter that would walk away from a 200gr bullet inside 500yrds with a good hit. At 2950fps with a 208gr bullet under 1 moa that's impressive.

 

[MThuntr]

magpro was my first adventure with dangerous high pressures associated with temp sensitivity. Had to use a rubber mallet to open the bolt.

 

[Buckbrush]

magpro was my first adventure with dangerous high pressures associated with temp sensitivity. Had to use a rubber mallet to open the bolt

Wow. I've had that happen with ramshot powder. Hunter and Big game. They really don't show much signs of pressure until it's way over pressure. I think I had my 270 win at 3400 fps with hunter and hard bolt lifts. Didn't even hit the paper at 100 yrds. But wow velocity was way up their.

 

[grizzly63]

I shot two heavier loads after the one I chose with no obvious pressure signs but not quite as tight of group. The temps I shot in should be close to hunting season. I will refrain from shooting any of them this summer in the heat. She does have some kick with these loads, even for an 10-12 lb gun. I think the extra long throat is helping keep the pressure down.