6.5x300 Weatherby Mag - Dialed in...

[Daggaboy73]

I'm new to the forum and I wanted to share some information and ask the opinions of others about Weatherby's new 6.5x300. I purchased the Mark V Accumark about a year ago along with all 4 boxes of ammo they had on the shelf – 127 gr Barnes.

I had dialed the 127's into the acceptable standard of 1' ½ groups at 100 yards that Weatherby advertises. Then I began to notice flyers after my first group thinking that the west Texas winds were affecting the 2nd groups. But then even on calm days my 2 groups opened up. (I always let the barrel cool, never rapid fire).

So I began researching things and talking to folks about what was happening. In short, I found that most were of the same opinion that 127g bullet was a bit light and was probably not stabilizing enough for the 1:8 twist barrel and all said I should try the heavier 130gr or 140gr bullets. Sounded right…

So I decided to reload from this point to find the right bullet weight and charge for my rifle. However there is very little published data. And no one from Hodgdon would talk about load data and the only current published data was Handloader Magazine, which I used as a road-map to begin my load tests.

I decided to try 3 different weight grain bullets and two powders, 4 rounds each:

130 gr AccuBond/US 869 (1' ½ groups at 100 yards)
140 gr AccuBond/US 869 (1 groups at 100 yards)
143 gr ELD-X/US 869 (3' ½ groups at 100 yards)


*130 gr AccuBond/Retumbo* for my rifle this was the most accurate, see pictures
140 gr AccuBond/Retumbo – did not test
143 gr ELD-X/Retumbo – did not test

So my questions, should I stop here, or have I only found the "floor" in terms of accuracy/velocity with this load? Should I begin tweaking this load slightly higher to increase my velocity until the accuracy begins to diminish? Should I try and work a different load for the 143 ELD-X that shot a 3.5 group?

I sort of know what my own answers are, but I'm looking for comments and other thoughts about this… thank you!

More test updates to come with velocity information…

 

[Trnelson]

The group on your picture looks pretty darn good to me. What is the SD of the load? If it prints like that and holds a SD less than 20 it is probably GTG for about as far as you want to send them. What a given rifle is capable of is a guess until you refine and study what works in it and what doesn't. I haven't shot any of the Nosler offerings in my 264 win mag, so I don't have any direct knowledge of what is possible. I usually look for at least .5MOA in my long range rifles. The load I shoot in my 264 win mag prints .4 MOA and holds a SD of 8 fps. I have been able to predictably hit steel out to 1,200 yard if I get the wind right...

 

[Daggaboy73]

Thank you for the input! I haven't chrono'ed anything, yet. I will be doing that over Memorial Day weekend and I will be updating this post with more information. I had only made those 4 rounds and was not excepting to get that good of a group right off the bat...

I agree, with you about the .5MOA for your longrange rifles, both my .300 WBY Mag and 30-378 WBY Mag shoot that and ring steel nicely at 1000 yards.

 

[okie man]

4 shots in one group. load up 10 more and if they all shot that good id call it a winner

 

[FURMAN]

With the short life of that barrel, if that load will repeat I would run with it.

 

[Daggaboy73]

Yep! 4 shot group and was I surprised to say the least after only 16 rounds of testing... only because from what I had been reading and hearing from others was that they were getting accurate groups, but nothing that was holding this tight of a group... my dad basically said the same thing, "pack it up, and load'em up..."

 

[Daggaboy73]

That's the thing with these overbore rifles, short barrel life... I agree... so I plan to repeat the testing, 4, 4 shot groups...

2 groups of 4 to verify;
2 groups of 4 to dope the scope...

Total # of rounds at that point = 71

 

[Dosh]

73, I like this new caliber. Try groups at two, three and four hundred yds to see how the load is going to perform at long range.

 

[Daggaboy73]

Dosh, I will be doing that and then some... groups at 700, 800, 1000, and 1200. But before I do that I'll post the results from 200, 300, and 400... I figure I should have all my results in by mid/June with less than 120 rounds thru it... Wish I had time to shoot this weekend...

 

[Rich Coyle]

tag

 

[codyadams]

I personally would not be shooting a 130 grain bullet in such a large cartridge if it's intent is long range, that is similar to loading a 150 or 168 in a 300 ultra, there is so much unrealized potential. But at the same time, with a barrel life of 700-1000 rounds, you don't want to shoot a ton just figuring out a load. And it also depends on how far you plan on using it. Less than 600? Its fine. But if your intent is up to 1000 or more for hunting...Here is what I would do.

Do what you plan, confirm that is a good load. At that point, you have only shot 26 rounds if you load 10 more to test, and you have a good load.

Then, I would take a look at Matrix bullets, particularly their 160 VLD, or other offerings in the 140+ range. The Berger VLD is a solid bullet, and the nosler 142 LRAB is also a good bullet, but can be finicky for loading and you need to research to get the proper bc, because the one they publish is inflated.

I have loaded a bunch of the eld line, and while i get decent accuracy and their on game performance is good, they don't hold the consistency as well. With the eld's, I get 20-30 fps e.s., and .5-.6 MOA. Switching to the Berger, single digit e.s. and .2-.3 MOA (on a different note, another person posted that if you are less than 20 SD it's fine...20 SD is not good, even for factory ammo. You essentially want 10 or less for SD. 20 would mean that about 66% of the time, your rounds would fall in a velocity range of 40 fps, and 33% would be even farther out than that) So I am now switching back to Berger.

But with such a large cartridge, my first try would be the 160 Matrix VLD, followed by the 140 Berger VLD or Hybrid. If I didn't get either of these to shoot, I would stick with your load you already have. If you aren't going to use this rifle as an every weekend shooter, you will still have plenty of barrel life left for hunting. It takes a LONG time to use 600 or more rounds in hunting scenarios, plus maybe 20 rounds of practice with that rifle a year. I prefer to have a smaller less over bore cartridge to practice with as much as possible, and save the big guns (once accuracy and trajectory is confirmed) for hunting.

This is just my opinion, others may disagree. That's ok.

 

[Daggaboy73]

Cody... Thanks for the input...

I'm basically looking for the most effective all-round longrange hunting bullet/load out to 1000 yards (basically the holy grail) of velocity and accuracy for my rifle... while I know not every bullet/load combination will shoot the same from rifle to rifle, and as one said, "study what works best in your rifle"... I'm planning to test some heavier bullets as you describe... I left 8 rounds untested, I was hoping to find the kind of accuracy that this (130gr) load shot in the heavier 140 Accubond or 143 ELD-X I left on the table, but I stopped after this group... end the day on a good note...

So I've been thinking maybe I should test these (140 and (143), as well as, the 142 Nolser Accubond Long Range... and I'll look into the other bullets you mentioned.

Thanks!

 

[codyadams]

Cody... Thanks for the input...

I'm basically looking for the most effective all-round longrange hunting bullet/load out to 1000 yards (basically the holy grail) of velocity and accuracy for my rifle... while I know not every bullet/load combination will shoot the same from rifle to rifle, and as one said, "study what works best in your rifle"... I'm planning to test some heavier bullets as you describe... I left 8 rounds untested, I was hoping to find the kind of accuracy that this (130gr) load shot in the heavier 140 Accubond or 143 ELD-X I left on the table, but I stopped after this group... end the day on a good note...

So I've been thinking maybe I should test these (140 and (143), as well as, the 142 Nolser Accubond Long Range... and I'll look into the other bullets you mentioned.

Thanks!

You bet. And that 130 is not a bad bullet, it will kill anything in north america at the velocity you are probably shooting them at, probably 3400-3500 fps...but I personally prefer to get the most performance out of a cartridge that is possible/reasonable. And when comparing the 130 accubond with a G7 bc of .225 going 3450 to a 160 Matrix with a G7 b.c. of .332 going 3200 fps or maybe more...they really don't compare. Especially when you look at the two side by side in a ballistics chart. Here is a 1000 yard comparison of the two using applied ballistics

PRESSURE: 23.3
TEMP: 50
6600 FT ELEVATION
10 MPH WIND

130 NAB @ 3450:
ELEVATION: 18 MOA
WINDAGE: 5.2 MOA
VELOCITY: 1872 FPS
ENERGY: 1011 FT. LBS

And just to compare that to my .260 Ackley (parent case a .308....) under the same atmospheric circumstances....

140 BERGER @ 3115:
ELEVATION: 20 MOA
WINDAGE: 4.7 MOA
VELOCITY: 1958 FPS
ENERGY: 1192 FT. LBS

So for all intents and purposes...your 6.5 300 Weatherby is being outperformed by the little .260 Ackley Improved cartridge. But if you did this....

160 MATRIX VLD @ 3200 fps:
ELEVATION: 18 MOA
WINDAGE: 4.O MOA
VELOCITY: 2120
ENERGY: 1596 FT. LBS

or this....

140 BERGER @ 3395 (FACTORY LOAD):
ELEVATION: 16.2 MOA
WINDAGE: 4.1 MOA
VELOCITY: 2185
ENERGY: 1484 FT. LBS

Then you really would be making that cartridge shine. If your gonna pay the prices (expensive brass, lots of powder, short barrel life) to have a magnum, you might as well get the most out of it and make it worth it!! Hope the ballistics I posted serve as a good visual to put it in perspective. Not trying to make waves!!! Just trying to help out a fellow shooter

Happy shootin!!!

 

[Daggaboy73]

Cody... thanks!

No waves made here... I'm all about gathering data to get the most out of this rifle/caliber. And it's why I was asking whether I have found the prefect combination of velocity and accuracy with this rifle... maybe, maybe not as you've pointed out. But lots of testing still to do, I'm going to send some more test rounds down range using heaver bullets... 140, 142, 143 ... as well as the 130/Retumbo loads. This time I'll have velocity and SD results...

At the end of the day I want others to have more than whats currently out there for this wildcat... even tho Weatherby has it in production, but short of any published data for reloaders - still a wildcat in my humble opinion...