Question about accuracy nodes..

If I find a node with a certain bullet type and speed, does this mean I should find a similar node with a similar grain weight bullet, type, and speed? I'm thinking the weight and charge develop a certain "barrel whip", and the node is the point where the bullet leaves the barrel as it crosses the zero point, or harmonic.

I'm also thinking that if, for instance, if i'm using 168 grain smk's, I should look for a similar node if I load to a similar velocity with 168 gr Gamekings...

Anyone try this??~~

In my experience, if we change "anything ", the node can and often does change. Different brand of bullit of the same weight, same bullet/different lot, different lot of same powder, different primer, different cases/and or lot, etc., etc.

In fact, in my experience, I would have to say, if something changes, and" doesn't " change the node, it would have to be a matter of luck?

JMHO...:-)

Will it be similar? Of course it will, BUT......

You need to be talking the same animal, so here is an example.
A 150gr super magical Booger bullet and a 150gr pro-hunter. Both have the same jacket material and weight. But the bearing surface is much different. So the results will differ. How much they differ may or may not matter, but the old story about: when things are different, they are different.

Yogie said that, right?

Just kidding, just kidding...;-))

I think it would be fairly close. The powder charge may have to change to get that same speed with a different projectile due to case capacity, bearing surface and other differences but I totally agree with your thought process.

Seating depth and powder charge.

Depends on how similar the two bullets.are. I would still back off.the charge a little and start.from there

I think you have to match exact type, and a match bullet type and a game bullet type are different.

Those are more styles of bullets.

Point of balance is not likely the same, internal material are different as is build.

Sierra makes two different match bullet types with different profiles (both in 168).

I don't think any two bullet mfgs profiles are the same either.

This could be a cool experiment.. unfortunately, It will have to wait till spring for me... I think you might be eventually find the resonant frequency for that barrel, and be able to predict the node speeds for most bullets.

I can't wait to hear the results!

Similar yes, the same, who knows. What you are looking for is dwell time or time bullet stays in the barrel. Similar time should put barrel near the same position in it's vibration pattern but odds are good that you will have to play with it some.

"when things are different, they are different" :-))

Simple answer is YES and NO

Yes a similar bullet will have a node around the same speed, most of the time.

I shoot 105vld 107smk around the same speed, around the same charge weight of the same powder and they have the same zero.

Are they both equally accurate though?

Quote:

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Originally Posted by RC20

Are they both equally accurate though?

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Yep. 107smk and 105vld's are the bullets and both average a lil under 1/2moa 5shots but the 107smk's seem to average a hair smaller groups than the 105vld's. It's what the barrel likes.

It's a 26" 243win Shilen bull.
42.9 - 43.1 gr of H-4831
Win Brass
210M primers

Most interesting thing is that about the same load was the most accurate in a 22" mod11 243win. 43gr H-4831/4831sc, Win brass, 210M and 105amax.