Is there usually a 2nd accuracy node?

bob4

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Naples Fl.
I did as Bergers describes for accuracy loading. 175G Match hunter, 71.5G H-4831( Bergers starting load) 1:10 twist, 26 inch barrel and a 300 WM @ 100yds. I settled on .090 off the lands, nothing came closer out of 4 groups total and FPS were all over the place except here. As I now want to increase the charge can I expect a second accuracy node?
FPS
1 2833
2 2843
3 2835
SD-5.2

 

FearNoWind

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North Central Valley California
I usually find accuracy nodes about 2 - 4 grains apart, depending on the rifle. If you work up about .3 - .5 grains at a time you may find another one but what you have looks promising. The groups looks good, but with only three rounds of data you don't really have enough reliable information to make a firm determination with this example.
I'd suggest you work up to the MV you believe you need (if you can get there safely) and then let seating depth smooth out the groups.
 

MagnumManiac

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I have ALWAYS found at least 2 nodes, one at the bottom of the velocity range and another nearer to the top velocity.
The 300WM is often at it's best right near the top of max pressure and velocity, normally within a grain or two of max loads/velocity.
If you try a ladder test, it should show 2 distinct groups, this is where you find your 2 or more nodes in a powder string.
H1000 is a far better powder choice than 4831, and Retumbo or RE25 are excellent choices, too.

Cheers.
gun)
 

SabreCross

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I've always found at least two. When doing so, I pay close attention to the standard deviation and the extreme spread. These factors will help me decide on my charge.
 

BountyHunter

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I have ALWAYS found at least 2 nodes, one at the bottom of the velocity range and another nearer to the top velocity.
The 300WM is often at it's best right near the top of max pressure and velocity, normally within a grain or two of max loads/velocity.
If you try a ladder test, it should show 2 distinct groups, this is where you find your 2 or more nodes in a powder string.
H1000 is a far better powder choice than 4831, and Retumbo or RE25 are excellent choices, too.

Cheers.
gun)
+1 on what he said
 

bob4

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Naples Fl.
I admit to having to get more shooting in on that load. Time constraints.:cool:. I thought if I approached 3000FPS I'de be doing well as long as the groups came back in. What more can I expect from Retumbo or H-1000? Better velocities? What type of velocities are other getting in their 300 WM ?
 

MagnumManiac

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I admit to having to get more shooting in on that load. Time constraints.:cool:. I thought if I approached 3000FPS I'de be doing well as long as the groups came back in. What more can I expect from Retumbo or H-1000? Better velocities? What type of velocities are other getting in their 300 WM ?
In my Kimber, with 26" barrel, 180's are running at 3160fps, 200's at 3060fps and 215's were just under 2900fps.
In my F-Class rifle, with 30" barrel, add another 200fps, roughly, for all bullet weights.
I know there will be dejectors as to my velocities, but my loads ARE pressure tested with a Pressure Trace II device.
RE25 gave the highest velocities, then Retumbo, then H1000 and RE22, which were very close to each other.

Cheers.
gun)
 

barefooter56

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Nov 10, 2014
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913
I did as Bergers describes for accuracy loading. 175G Match hunter, 71.5G H-4831( Bergers starting load) 1:10 twist, 26 inch barrel and a 300 WM @ 100yds. I settled on .090 off the lands, nothing came closer out of 4 groups total and FPS were all over the place except here. As I now want to increase the charge can I expect a second accuracy node?
FPS
1 2833
2 2843
3 2835
SD-5.2

bob4,
Likes has already been stated. You will usually find more than one velocity accuracy node. But the seating depth accuracy node is usually a one time find. At least that has been my experience.
 

jsthntn247

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Jan 14, 2009
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708
Accuracy nodes come 3% apart on powder charge. Some are more accurate than others with a lower ES
 

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