Well I just got back from the range. Last night I was disappointed, of course, with the results of my little hyposthesis on my .300 win mag with the Hornady 165 gr SST. When I pushed the velocity to where I wanted it, I was not able to tune a decent load with seating depth or reductions in charge weight.

Last night I loaded some Sierra 165 Gamekings up with the same charge weight, 79 gr H-4831. I varied the seating depth like this: first 3 at .020" off the lands, next 3 at .040" off the lands etc. until I had 12 shells.

I guess my rifle doesn't like the SST because IT WORKED with the Gameking! After shooting the second group I had found a good load (seating depth). That's just 6 shots and I have a good load.






That's a photo of the two groups. The first one is on top and was a seating depth .020" off the lands. The lower group is the second group fired and was seated .040" off the lands.







This is the good group close up. I just measured it and it is 1.25 inches. This was shot at 200 yards so it is well under 1 MOA. The last two sets of test cartridges opened back up to just being a tad better than the first group's picture. I didn't include them here.

I think some TINY adjustments (by .005") in seating depth or .3 gr adjustments in charge weight may tune the load even further. This is what I did with the .243 wssm and it helped. I did the shooting with the .243 at 300 yards. I did it at 200 with this gun to eliminate the possibility of ME being a factor. I think at 100 yards the results would be similar.

One 3 shot group doesn't prove alot but it IS POSSIBLE you are onto something. Many years ago I had a fussy browning bar. I went to the range with a new recipe and promptly shot a 5 shot 1.25" group and thought I had found some "magic". Went home and loaded up 20 the same way and went back to the range only to find out they didn't shoot any better than anything else.
Load up about 10 more of your recipe and head on back.....you may have something...you may not..but you will find out soon.

Will do kraky,

But to let you know, I've already proven that I'm onto something. I did the same thing with my .243 wssm with the same method and it worked.

I'm not the originator of this hypothesis, come to find out. Check the Berger website. They say to do exactly this with their VLD.

I really believe that it will work with this gun too and yes I've experienced what you are talking about. You think you found a good load, you load a bunch up and go to the range only to find out they suck.

I've loaded plenty of .243 wssm's up and been back to test them........they're good.

I'll keep everyone posted on the .300 "test gun" as well; and you know I'll post the results as I've proven, good or bad.

its great when it all comes together - now try noslere bts and partitions. ias a died in the wool sierra guy I've found the noslers frequently outgroup then in 30 cal hunting type bullets

Thanks butchloc,

I already have a load for the .300 with 180 gr Accubonds going 3130 fps that shoots well; 1 MOA or less.

The only reason I gave the SST and the Gameking a try was to test the theory of which should come first, finding the seating depth the gun likes or the weight of charge it likes. It's purely a "scientific" test. After having poor results shooting ladders I determined that the seating depth really effects the way any load with a set charge weight shoots. It seemed that the seating depth was choosing the charge weight it liked when I shot the ladders. Furthermore, if you had chosen a seating depth that was bad for accuracy across the board for the bullet, nothing would be accurate and you would just reject that bullet and powder and move on to the next.

So I began to think that maybe you could tune any charge weight to be accurate by just changing the seating depth. I like the highest velocity possible in the rifle so I chose the safest/highest velocity charge weight and then just tried to tune it to be accurate with seating depth changes. It worked well and with much less shooting than the conventional methods.

I then chose the Berger VLD to try to develop a load. I knew that Berger had some recommendations about seating depth for the VLD so I went to the website to search for it. Low and behold..........On their website it says to do just what I found out on my own to develop a load for their VLD; pick a load (charge weight) and load 12 shells just varying the seating depth. After shooting them it says that you will find one that out performs the others. It goes on to say that further tuning can be done with depth and charge weight from there but most people are happy with the first test alone.