7mm Rem Sendero with 168 Berger testing

[Dr. Vette]

Today I had a chance to test my 7mm Sendero with its first handloads.
My goal with the rifle is to attempt to do as well or better than the HSM ammo, which my rifle shoots relatively well at 3010fps. I am using the same brand of primer and case, as well as the same length to the ogive when loaded.

Powder is H-1000
Winchester cases (trimmed, annealed, etc) were used with Remington 9 1/2M primers.
Distance is 200 yards.
Chrono is my Master Chrony. It was about 50 degrees today, minimal wind.
Shooting was done in a round robin fashion starting at 68.5 and working my way up.
I spent a fair amount of time scouring the LRH site for loads using H-1000 and the 168 Berger, and almost everyone's "pet" load was 69-70gr, so I focused in this area.

See the attached targets for specifics. Note that the 2nd target and 4th target of the bottom row were used for other rifles, and therefore are not marked.

Interesting notes:

the loads with the best ES don't have the best groups (see 70.0 vs 70.5)
some loads have quite a bit of ES, and I have no idea why. I wonder if the second 68.5 should have been 2936, not 28?
The unmarked second target of the bottom row - the two far right shots about 1/2 inch apart are the fouler loads for this rifle with 68.5gr powder. I then moved the scope crosshairs over but you can see they were obviously very close together.

I'm a bit stumped as to which direction to go from here. I've tried to look at it from a "smallest group" perspective, or looking for a node, or looking at it from an OCW perspective. No answers jump out at me thus far.

Any thoughts from the experienced shooters?

 

[MudRunner2005]

I don't do like most people and study the targets... I look at whichever load charge gives me the tightest group from my .5gr incriment initial ladder, to where it started opening up, then I test from point A to point B in .1gr incriments to find which one shoots the tightest group pattern. Then I stick with that one.

 

[brentc]

You need to find the seating depth your rifle likes. The OCW rarely works with Bergers until you find your seating depth. Try backing the 168 to .070" off your lands and run between 70.5 and 71.0 grains of H1000 with a CCI 250 to see what you come up with. Mine usually end up at 70.7 or 70.8. You should see somewhere between 3000-3025 fps and sub 10 ES.

FYI the Sendero's I've loaded for are throated for a 168 to touch the lands at or near 2.726" Base to ogive. At .070 off, my loads end up at 2.956 Base to ogive

 

[ShootnMathews]

The 70 grain charge is around .4 Moa which isn't bad. I'd try 70.2 and 68.8. And see if those do better or worse. If one does better than 70 I'd try another group in that direction.

 

[Dr. Vette]

Thanks guys. I'll try to fine tune the seating depth and see what the rifle likes. Of course, since additional Bergers aren't available from any vendor anywhere I'll have to be a bit judicious how I use the rest of this box.

 

[MudRunner2005]

Thanks guys. I'll try to fine tune the seating depth and see what the rifle likes. Of course, since additional Bergers aren't available from any vendor anywhere I'll have to be a bit judicious how I use the rest of this box.

Save your hunting VLD's and buy you about 5 boxes of these...

https://www.grafs.com/retail/catalog/product/productId/852

Bullets.com has the Hunting VLD's in stock... I've ordered from them before with no issues.

https://www.bullets.com/products/7mm-284-168-Grain-Match-VLD-Hunting-Bullets-Case-of-100/BL10097

 

[8andbait]

to me it looks like the 70.5 load is a scatter node so 1.5% on either side should be your node. So, 69.5 and 71.5 (if safe) should get you real close.
I would load 3 at 69.3, 69.5 and 69.7 and see what happens. I believe all of these groups will impact very close to each other even though they are different charges.

Gary

 

[brentc]

Once the seating depth is found all the groups will tighten up and you'll be able to see which one is truly the winner.

 

[brentc]

to me it looks like the 70.5 load is a scatter node so 1.5% on either side should be your node. So, 69.5 and 71.5 (if safe) should get you real close.
I would load 3 at 69.3, 69.5 and 69.7 and see what happens. I believe all of these groups will impact very close to each other even though they are different charges.

Gary

I understand what you see here, but it doesn't tell the whole story. The 70.5 group could turn into a 1/4 MOA group with a simple change of seating depth. The VLD has different wrinkles that you need to deal with sometimes. Often times they just will not shoot when seated within .020 of the lands, which I presume is what's happening here. For the 70.5 grain load, the single digit ES is a good indicator of the consistency of this powder charge. Use this charge to perform a seating depth test.

Thanks guys. I'll try to fine tune the seating depth and see what the rifle likes. Of course, since additional Bergers aren't available from any vendor anywhere I'll have to be a bit judicious how I use the rest of this box.

Since you have only a few bullets left and if you know where your lands are, try .070 off and see what you get. There are generally no shortcuts but this one has been hashed out a few times. Heck, try loading up three shots each at 2.956 base to ogive with 70.5, 70.7, and 70.9 and see what you get. I'm really curious to see how this turns out.

 

[Jumpalot]

Saw a post by Kirby a few years ago about how to find a load. Decided to try it. Load up until you see pressure, then back it down 2 grains. Tweak seating depth if needed then go kill stuff. Worked on my 7 mag with 168 Bergers at 3030 fps. Also on my 300 WM with 215 Bergers at 2950 fps. Tested out past 800 yds and both hold sub moa. Told my buddy to do the same on his Sendero 7 mag and similar results. Maybe we got lucky. Saved a bunch on components though so I'm not complaining. Don't ask what the ES is as I don't know. Don't shoot over a chrono anymore. If it groups well at distance, I don't care what the ES is. The velocities were figured to match drops.