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mike in co
Guest
i see the short range guys talking about 3 or 4 nodes in 6ppc. are thier similar nodes in 300 win mag ? 210 gr bullet...
thanks
mike in co
thanks
mike in co
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N
nhkuehl
Guest
Nodes
The short answer is yes. I'll leave it at that and let the experts explain what that is and how it affects accuracy. - nhk
The short answer is yes. I'll leave it at that and let the experts explain what that is and how it affects accuracy. - nhk
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mike in co
Guest
i was actually looking for numbers....velocity windows...if known...
thanks
mike
thanks
mike
Sorry, you'll have to do your own work. Bullets are ignorant of the speed they're moving at; they really have no preferences--or any emotions, for that matter.
"Nodes" is shorthand for "no vertical." And that is a time-in-bore/vibration phenomena, which in turn depends on barrel length, contour and powder (determines terminal velocity & rate of acceleration). In short range benchrest, just about everybody uses VV N-133, with barrel lengths around 21-22 inches. In 1K benchrest, with the .300 Win Mag,you seen barrels from 27 to 34 inches, in different tapers, and powder choices from 4350 to H-1000. If you want to borrow numbers, you'll have to get more specific.
"Nodes" is shorthand for "no vertical." And that is a time-in-bore/vibration phenomena, which in turn depends on barrel length, contour and powder (determines terminal velocity & rate of acceleration). In short range benchrest, just about everybody uses VV N-133, with barrel lengths around 21-22 inches. In 1K benchrest, with the .300 Win Mag,you seen barrels from 27 to 34 inches, in different tapers, and powder choices from 4350 to H-1000. If you want to borrow numbers, you'll have to get more specific.
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mike in co
Guest
thanks charles...i knew the short range guyes were in a very narrow band of variables. so in my case, 300 win mag, 210 bullets, h1000 powder( with 4831 and ramshot magnum available) 28" heavy contour bbl gun will weigh in at 17 lbs.
or as you said , i'll have to go shoot it and see. was just hoping for some known data...oh well
thanks
mike in co
or as you said , i'll have to go shoot it and see. was just hoping for some known data...oh well
thanks
mike in co
N
nhkuehl
Guest
Finding the node
Like it was stated it's barrel harmonics and burn rate characteristics of powder and has to be 'tweaked' for each barrel or with a tuner. There are basically two methods I'm aware of to find the node; 1) the ladder test, shooting 20 or more rounds of increasing powder charge within the min-max range at 300 yds or more, keeping track of each shot, and look for clusters in the vertical dispersion. 2) shoot groups of uniform charge increments (which I do and increase powder ~1% of min) at 100-200 yds and plot group size and and look at vertical and horizontal. You should see a wave pattern of group sizes increasing and decreasing over a range of loads. Compare that to velocity and standard deviation and watch for plateaus in velocity and pressure signs. I can only address how I have done it and I'm sure others may not agree with me and will offer their methods. - nhk
thanks charles...i knew the short range guyes were in a very narrow band of variables. so in my case, 300 win mag, 210 bullets, h1000 powder( with 4831 and ramshot magnum available) 28" heavy contour bbl gun will weigh in at 17 lbs.
or as you said , i'll have to go shoot it and see. was just hoping for some known data...oh well
Like it was stated it's barrel harmonics and burn rate characteristics of powder and has to be 'tweaked' for each barrel or with a tuner. There are basically two methods I'm aware of to find the node; 1) the ladder test, shooting 20 or more rounds of increasing powder charge within the min-max range at 300 yds or more, keeping track of each shot, and look for clusters in the vertical dispersion. 2) shoot groups of uniform charge increments (which I do and increase powder ~1% of min) at 100-200 yds and plot group size and and look at vertical and horizontal. You should see a wave pattern of group sizes increasing and decreasing over a range of loads. Compare that to velocity and standard deviation and watch for plateaus in velocity and pressure signs. I can only address how I have done it and I'm sure others may not agree with me and will offer their methods. - nhk
Nah. I have a good BAT action & use RWS brass. I load until I see too much pressure, usually the beginnings of an ejector mark on he case head. Now we can only go one way -- down. Depending on the powder, I usually go down a grain at a time, until the vertical goes away. Now is the time to fiddle with 1/2 grain increments if you feel it necessary.
I DON'T recommend this, obviously, the old ejector-mark-on-the-case-head method involves too much pressure. If you think it is safe in your rifle, that's your business.
May all change if you test at 75F and shoot 90F.
Danny Brooks is the master of the .300 Win Mag. Believe he likes 4831, but I'd ask him.
I DON'T recommend this, obviously, the old ejector-mark-on-the-case-head method involves too much pressure. If you think it is safe in your rifle, that's your business.
May all change if you test at 75F and shoot 90F.
Danny Brooks is the master of the .300 Win Mag. Believe he likes 4831, but I'd ask him.
Mike in Co
The old standby load for the 300 Win mag used to be a 190 Sierra at 2950 fps but like was posted earlier the velocity node goes up or down with the barrels length.
My 300 likes the 200 grain Sierra's and 74 grains of H1000 is a very good starting point.I go up in 0.7 grain increments.
Lynn aka Waterboy
The old standby load for the 300 Win mag used to be a 190 Sierra at 2950 fps but like was posted earlier the velocity node goes up or down with the barrels length.
My 300 likes the 200 grain Sierra's and 74 grains of H1000 is a very good starting point.I go up in 0.7 grain increments.
Lynn aka Waterboy