300 MP in a 357 Magnum Rifle Results.

Deja vu · November 7, 2014, 11:52 AM

I have been meaning to test out these in my carbines. What I got it a 140 grain Hornady bullet in Federal Brass with a Federal Small pistol primer. The load was 20.5 grains of Power Pro 300MP.

From my Coonan they are getting about 1650ish FPS (if memory serves) but are very uniform.

From my Ruger 18.5 inch barrel 77/357 here is the shot string in FPS.

1. 2101
2. 2108
3. 2119
4. 2116
5. 2110
6. 2113
7. 2098
8. Error
9. 2110
10. 2114

Because of the error I shot 1 more

11. 2112

High 2119
Low 2098
Average: 2110

any way I am happy with these. The shots seem pretty uniform and the 300mp has different tone. It sounds lower than most my other loads... not sure why. Accuracy was less than I hoped for but still suitable for deer at 100 yards. Got about 2 inches at 100 yards.

If I have time this weekend I may try them from my 16.5 inch Marlin.

Sevens · November 8, 2014, 06:02 PM

I keep meaning to bother ATK and I keep forgetting. Layne Simpson published recently in an article that Power Pro 300-MP and H110 are the same powder, but the dreamer in me does not want to believe it.

I have no H110 and my plan has been to never have any, but I do have 300-MP. Your results look extremely encouraging -- makes me wonder if you have any plans to compare it directly with H110 to see if they return same results?

November 7, 2014, 11:52 AM	#1
Deja vu Senior Member Join Date: March 14, 2010 Location: Border of Idaho & Montana Posts: 2,584	300 MP in a 357 Magnum Rifle Results. I have been meaning to test out these in my carbines. What I got it a 140 grain Hornady bullet in Federal Brass with a Federal Small pistol primer. The load was 20.5 grains of Power Pro 300MP. From my Coonan they are getting about 1650ish FPS (if memory serves) but are very uniform. From my Ruger 18.5 inch barrel 77/357 here is the shot string in FPS. 1. 2101 2. 2108 3. 2119 4. 2116 5. 2110 6. 2113 7. 2098 8. Error 9. 2110 10. 2114 Because of the error I shot 1 more 11. 2112 High 2119 Low 2098 Average: 2110 any way I am happy with these. The shots seem pretty uniform and the 300mp has different tone. It sounds lower than most my other loads... not sure why. Accuracy was less than I hoped for but still suitable for deer at 100 yards. Got about 2 inches at 100 yards. If I have time this weekend I may try them from my 16.5 inch Marlin. __________________ Shot placement is everything! I would rather take a round of 50BMG to the foot than a 22short to the base of the skull. all 26 of my guns are 45/70 govt, 357 mag, 22 or 12 ga... I believe in keeping it simple. Wish my wife did as well... Last edited by Deja vu; November 7, 2014 at 11:58 AM. Reason: Add accuracy and the disclaimer in my Coonan Velocity.

November 8, 2014, 06:02 PM	#2
Sevens Senior Member Join Date: July 28, 2007 Location: Ohio Posts: 11,756	I keep meaning to bother ATK and I keep forgetting. Layne Simpson published recently in an article that Power Pro 300-MP and H110 are the same powder, but the dreamer in me does not want to believe it. I have no H110 and my plan has been to never have any, but I do have 300-MP. Your results look extremely encouraging -- makes me wonder if you have any plans to compare it directly with H110 to see if they return same results? __________________ *Attention Brass rats and other reloaders:* I really need .327 Federal Magnum brass, no lot size too small. Tell me what caliber you need and I'll see what I have to swap. PM me and we'll discuss.