This is my first post here on this site. I'm an avid Hunter, shooter, and reloader. I've been reloading since about 13 years old and am not 47. Don't claim to know it all but I feel pretty comfortable with loading ammo.
I've done several searches here looking for information on the 150gr Partition and IMR 7977 and came up empty. I decided to do a little experimenting on my own and go based on what Hodgdon had listed. I started at 58gr and worked up to 60gr. Wasn't sure the flat based Partition would produce more pressure than the Hornady bullet so I stopped there.
My rifle is a Winchester model 70 Featherweight with the 22" barrel.
All rounds loaded were loaded 20 thousandths off the lands at 2.776"(Comparter).
I used virgin Winchester brass and Federal 215 match primers.
All shots were from my bench with rear bag.
Velocity was measured on a MagnetoSpeed Chrono with fresh 9v battery.
Distance was 110yds (100M) it just worked out that way today.
The groups were less than stellar from 58gr to 59.5gr. The 60gr load produced sub 1 inch 5 shot group(i've never shot under an inch with a Partition in any of my other rifles).
I didn't see any of the typical pressure signs so I know I have a ways to go.
The velocity wasn't what i'm looking for at this point. I'm looking to be in the 2900fps realm but right now with the 60gr load i'm sitting at 2843fps average. Not sure .8 of a grain will get me much more velocity.
I brought a box of the Hornady Precision Hunter ammo with the 145gr ELDX along to see how they perform as well. 2790fps (2970 advertised on box)was what I recorded for 5 shots and accuracy was not that great either. Second caliber that i've bought and my rifles don't like.
I've done several searches here looking for information on the 150gr Partition and IMR 7977 and came up empty. I decided to do a little experimenting on my own and go based on what Hodgdon had listed. I started at 58gr and worked up to 60gr. Wasn't sure the flat based Partition would produce more pressure than the Hornady bullet so I stopped there.
My rifle is a Winchester model 70 Featherweight with the 22" barrel.
All rounds loaded were loaded 20 thousandths off the lands at 2.776"(Comparter).
I used virgin Winchester brass and Federal 215 match primers.
All shots were from my bench with rear bag.
Velocity was measured on a MagnetoSpeed Chrono with fresh 9v battery.
Distance was 110yds (100M) it just worked out that way today.
The groups were less than stellar from 58gr to 59.5gr. The 60gr load produced sub 1 inch 5 shot group(i've never shot under an inch with a Partition in any of my other rifles).
I didn't see any of the typical pressure signs so I know I have a ways to go.
The velocity wasn't what i'm looking for at this point. I'm looking to be in the 2900fps realm but right now with the 60gr load i'm sitting at 2843fps average. Not sure .8 of a grain will get me much more velocity.
I brought a box of the Hornady Precision Hunter ammo with the 145gr ELDX along to see how they perform as well. 2790fps (2970 advertised on box)was what I recorded for 5 shots and accuracy was not that great either. Second caliber that i've bought and my rifles don't like.