Sako 300 Win Mag Issues?

[deertroy1]

I have a Sako rifle with a Hart 300 Win Mag 1-10" barrel. I have struggled with consistent accuracy from day one. One day the rifle will shoot a particular load into 0.5". I'll load some more and they now group 1.5". I have tried H1000, H4831, H4350, Rx22, Rx17 and IMR7828 powders. For bullets I have tried Berger 168, 175 and 185 VLD Hunting, Nosler 150, 165 and 180 AccuBond and Hornady 150 165 and 180 Spire Point, Hornady 165 SST and 180 Inner Bond.
I have also tried a different scope.
My friend suggested that I should put the expander button in my Redding Type S full length die as without turning necks I will get inconsistent bullet pull without it. Redding post this on it's site:

Question: Do I need to use the expander button that came with my Type "S" Die?
Answer: It is advisable to use an expander button to maintain consistent neck tension if the case necks have not been turned to a uniform wall thickness. However, the expander button can be replaced with the Decapping Pin Retainer (included with your Type "S" Die) if the user does not wish to use an expander button.

so I guess he is correct. I installed a carbide expander button but accuracy still remains inconsistent.
The barrel work was done by Dan Dowelling and the rifle was bedded by T&M Stock Works. Just to be sure I had the rifle rebedded and recrowned.
I have tried different seating depths and have measured my bullet runout at 0 to 0.002" max.
Any ideas?

 

[deertroy1]

Here's an example. The group on the right was shot July 1, 2013. The group in the center was loaded with the exact same components?

 

[hawk45]

Don't take this as an insult, but have you had some else try and shoot the gun? Is the barrel floated? Screws properly torqued? Have you been cleaning before/after groups? Does it run better dirty vs clean? Do you have a brake on it?

 

[deertroy1]

Don't take this as an insult, but have you had some else try and shoot the gun? I don't feel insulted at all. That's a legitimate question. The answer is yes others have tried. I can shoot good groups with similar recoiling rifles (see below). Is the barrel floated? Yes. Screws properly torqued? Explain? Have you been cleaning before/after groups? Clean after every 15 to 20 rounds. Does it run better dirty vs clean? No difference. Do you have a brake on it? No.

 

[BMF]

Have you weight sorted your brass? Because from experience, 300WM brass can vary alot, sometimes 10-20grs. Also i see you posted the velocity, is that chronographed or just per the reloaders manual? Im not questioning your numbers just trying to eliminate some variables.
Brent

 

[deertroy1]

Have you weight sorted your brass? Because from experience, 300WM brass can vary alot, sometimes 10-20grs. Also i see you posted the velocity, is that chronographed or just per the reloaders manual? Im not questioning your numbers just trying to eliminate some variables.
Brent

No I haven't weight sorted my brass. The velocity was chronographed with an Oehler 35P. I'll weigh the brass and let you know the difference.

 

[roninflag]

deer- all your groups should look like the .55 one out of a hart/sako. something loose.

 

[deertroy1]

deer- all your groups should look like the .55 one out of a hart/sako. something loose.

I haven't found anything. Checked the mounts, stock screws, etc.

 

[FEENIX]

Mine is 1:11 with 23 1/2" factory barrel and seems to like 180gr and heavier 0-.010" off the lands. Below group is at 100 yards with 71.5 H4831SC, 200 NAB, and CCI250. Load was developed a couple of years ago and haven't had a chance to further explore it.

I hope you have it resolved soon. Good luck

Ed

 

[deertroy1]

I'd be pretty happy if mine would consistently do that? Here's mine. It's had WE Birdsong Black-T applied.