Need help with .30-06, 180 NP and IMR 4831

[sniper208]

I am loading my son's 22" Stevens (Savage). My rifle loves the 200 NP. I have limited funds, time and range availability so I want to make my efforts count. Does anyone have a pet load I can try & tweak? My SIG .30-06 consistently yields 1/4" groups (inside measurement) at 100 yards with the 200 Partition (53.2/IMR4831). I will be using Remington Large Rifle 9 1/2 primer, Remington brass and IMR 4831 powder (that's what my rifle prefers). I get 1/2" groups with the 165 Partition and his rifle duplicates this result (53.9/IMR4831). Both rifles/loads might be able to be improved, but I cannot hold any better than this.

I have two boxes of 180 Partition and want to give him the best performance possible. I would like to try to stay with this powder simply to save time, money and frustration, but I am open to changing for his rifle if needed. Any ideas?

 

[grizz007]

Nosler 5th ed. gives 53.0 grns @2535fps--57.0grns@2763fps. with your bullet choice. These are the lows and highs of powder and bullet-have fun.

 

[sniper208]

Thanks! I have the manual. After reading the manual I am confused on why it takes more powder in the 180 than the 200. From a physics perspective, it just doesn't make sense. What I am looking for, however, is someone who already has a pet load for the 180 Partition with 4831 I can use as my starting point, then tweak it up or down as needed.

 

[mshaffer]

The physics behind the lighter bullet needing a heavier charge has to do with pressure. There is more effort needed to push a heavier bullet through the barrel, thusly the charge needs to be adjusted accordingly to create comparable chamber pressures and overall performance with different makes and weights of bullets. You'll always find higher powder charges in load data for smaller bullets within a given cartridge.

 

[Northwoods Hunter]

Those SIG Sauers are shootin machines!

My Sako FinnBear shot 200gr SBTs under an inch with 57.5 gr of RE 22 but it had a 24" bbl.
I dont know how it will work in a 22" bbl. You may want to look up a 200gr load with something like RE 19 for a shorter bbl.

The 180s will actually have better long range energy than the 200 gr... I am going to try some 180gr NPTs out of my LazerMark 06....it has a 26" bbl.

 

[FOTIS]

start at 54 gr and work up.