308 load development?

zr600

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Ok my wife has a moose hunt coming up, she's going to use her 308 savage. I have it shooting 150g Sierra pro hunters 1/2" or so. I also have it shooting 168 Sierra tmk 1/2" or better. So I wanted a heavier and better penetrating bullet for the moose hunt so I ordered some 166g shock hammers. Anyways I run a Satterlee latter test with them had a flat line at 41.8-42. So I loaded 41.9 and grouped them and they shot a 2" group. Kind of disappointed so far. Could it be the seating depth? The tmks took some work with seating depth to get them to shoot but when I got it they shoot good. The powder used was varget, primers Winchester large rifle, and Winchester brass that's been prepped. So I'm just kind of worried with getting closer to hunting season. Velocity was 2707 for 41.8 and 2706 for 42g. Any advice would be great. This gun does have a 20" barrel too.
 
Try another powder. You should be in the right range for burn rate.
Unless your rifle is extremely finicky, you should get sub 1" groups. How much jump do your bullets have? Hammers aren't real sensitive to jump. Loads from .020 to .150 usually work fine. Powders from Ramshot TAC to CFE 223 seem to do well. Refer to Hammer Hunter Load Data thread on Longrangehunting.com.
 
Some barrels just don't like what we think they should. That combo you are using should produce better groups than what you have indicated. I have never had great success with the Satterlee test alone. I have had better success finding the point of pressure and then backing down a grain or so. Here I shoot 3 shot groups in half grain increments to find the best group. I usually shoot about 20 - 30 thousands off the lands for this point in the tuning process. Once I have a good group, I fine tune with seating depth.

Sorry for rambling. I am sure you know what you are doing. The only other thought is your barrel twist rate may not be adequate for that Hammer bullet. If you have not contacted Steve, I think that would be the best recommendation to resolve your issue.
 
his twist rate is fine the savages have a 1-10 twist and normally are not to hard to tune. I have 2 a heavy barrel target and a light weight 20" axis and both will shoot just about anything you through at them.
 
his twist rate is fine the savages have a 1-10 twist and normally are not to hard to tune. I have 2 a heavy barrel target and a light weight 20" axis and both will shoot just about anything you through at them.
Assuming it's a newer bolt action. If it's a older Savage 99 or a older bolt rifle it can be just about anything.
 
The twist is 1.11, I'm going to clean really good and try again. Also going to try h4895 on recommended by Steve he was thinking erotic velocity numbers might be the powder not all burning in the shorter barrel. I'm going to clean and try them again then try h4895 also to see if I can get some better results maybe. Will see what happens they were .020 off the lands.
 
I used CFE with the 152 HH in my 20" 308 1-10.25 twist for 2815 FPS.

I tried the 181s but would not stabilize. You may want to check your twist with a cleaning rod. I ordered a 10 twist but found out not so much when I tried the 181s. I think these monos feed on faster than normal twists.
 
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Shorter barrel-faster powder may be the ticket. @ButterBean is a expert in the hammer arena. I think he's got a few 308 loads and can probably chime in. A slight crimp may help with powder burn also in the shorter barrel. Lee makes a 308 crimp die that's about $10 and can help a ton with getting consistent loads. Good luck on your Moose hunt and let us know how it goes. Got to love it as the season is just around the corner. I leave on a SpeedGoat hunt in 3 weeks.
 
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