load to the node?

[Martin52]

Load testing at say 300 yards then, if the load causes the bullets trajectories to cross at about 200 yards, we should see the reverse - with faster bullets printing higher than slower ones. If I am interpreting Varmintal's work correctly, this pattern is positive compensation.

 

[Nick Caprinolo]

I think I understand what you are trying to say, but it is an oversimplification. Two paths (fast, high BC, low angle - aka fast ball vs. not so fast, okay BC, high angle - aka slow pitch) can hit the same point of impact. The consistency with which each of those paths can be repeated is what I believe you were talking about.

The slo pitch will take a longer time arriving at that point. If he throws the same pitch to the same height and speed, all his pitches should arrive at point of aim. If he varies the speed, the pitch will change the point at which it reaches the same level. Faster and it will be long slower and it will be short. Confusing I know but I believe you understand what I am implying.

 

[Bart B.]

Load testing at say 300 yards then, if the load causes the bullets trajectories to cross at about 200 yards, we should see the reverse - with faster bullets printing higher than slower ones. If I am interpreting Varmintal's work correctly, this pattern is positive compensation.

Yes indeed. Grade school reasoning. Not complicated.

 

[kthomas]

I believe so.

For example, I've found with the 6.5 Creedmoor on 24" heavy contour barrels (MTU) they seem to really like to shoot the 140 grain bullets around 2830 fps. This has been repeatable with a couple of barrels.

I've only had one 6 BRA barrel so far, but it seems to be happy around ~2970 fps, 28" heavy varmint. It seems like others are around that same velocity with 105's.

 

[lh leggtowner]

Remember that all free floating barrels for a given cartridge with the same steel, weight, length and profile will have the same resonant vibration low frequency and several harmonic vibrations higher frequencies.

The amount and vertical direction the barrel bore axis vibration at the muzzle whips and wiggles at is determined by the load and bore/recoil axis above the rifle's center of mass and how the rifle's held.

Best accuracy happens when all bullets leave on the muzzle axis up swing so faster ones with less barrel times leave at slightly lower angles to the LOS than slower ones with more barrel times that'll leave at higher angles.

Therefore, the same load will shoot equally accuracy across several rifles with the same build specs. This was common with military teams shooting the same spec'd rifles

THis is what I was trying to convey in my statement. I just didnt have enough sense to say it like that. I appreciate you explaining it. I just knew after reading SEVERAL post almost everyone had the same velocities with the same cartridge.... in a sense. Not exact but close. And also, everyone was pretty much shooting the same type rifle.

Thanks Bart for explaining for me what I could not.

 

[lh leggtowner]

My answer to your original question is yes! I see it time and time again with 6ppc, 6BRA and 6BR.

Bart

love the simple answer.

 

[garandman]

What will work for your gun = What actually ends up working in your gun.

After you Chase all the Internet opinions and listen to what every body else will tell you Will work in your gun and then you buy all the equipment and implement and test their theory... You could have just run your own ladder and OCW tests and have your load.

There is no substitute for doing your own homework. That's because universals are rare as dinosaur eggs in precision shooting. There are just too many variables.

 

[Tempest]

What will work for your gun = What actually ends up working in your gun.

After you Chase all the Internet opinions and listen to what every body else will tell you Will work in your gun and then you buy all the equipment and implement and test their theory... You could have just run your own ladder and OCW tests and have your load.

There is no substitute for doing your own homework. That's because universals are rare as dinosaur eggs in precision shooting. There are just too many variables.

^^^ This.

Only thing I have to add, as mentioned I also shoot the lower node for various reasons.

 

[F Class John]

What will work for your gun = What actually ends up working in your gun.

After you Chase all the Internet opinions and listen to what every body else will tell you Will work in your gun and then you buy all the equipment and implement and test their theory... You could have just run your own ladder and OCW tests and have your load.

There is no substitute for doing your own homework. That's because universals are rare as dinosaur eggs in precision shooting. There are just too many variables.

Bingo dingo ^ I totally agree.

I am a firm believer that the gun will tell you what it likes but it takes NOT being lazy to figure that out. To the OPs point, could anyone use the ‘average load’ on the internet for any given cartridge and shoot GOOD scores, of course. But all other things being equal, GREAT scores come from tuning a load to you barrel. Every new barrel I spin up, and all my barrels are exactly the same (and that was 5 this year) gets its own load development. I use the same process every time and while my loads are usually close each time they are often just a little different each time. And to the OP, the powder/speed node is just one part of the loading equation towards great accuracy. Five guys could all load for the same barrel using the same powder charge but all the other steps involved will yield five different groups or water lines. There’s no one perfect answer for how to load for everyone, but there will always be one perfect way that works for you and that’s ok and the way it should be.

 

[Shinbone]

Attached are 7 graphs of "group size vs velocity" for 7 different loads in a single rifle. The first 5 graphs are for a 117gn bullet, the last 2 graphs are for a 120gn bullet. Rifle is a Winchester M70 in .264WM. For most (but not all) of the loads, there is a consistent accuracy node at 3350-3370 fps from powder-to-powder and bullet-to-bullet. Not saying that others shooting a .264WM will find an accuracy node at 3360fps, but clearly this gun likes that muzzle velocity regardless of what powder got it there.

 

[lh leggtowner]

Attached are 7 graphs of "group size vs velocity" for 7 different loads in a single rifle. The first 5 graphs are for a 117gn bullet, the last 2 graphs are for a 120gn bullet. Rifle is a Winchester M70 in .264WM. For most (but not all) of the loads, there is a consistent accuracy node at 3350-3370 fps from powder-to-powder and bullet-to-bullet. Not saying that others shooting a .264WM will find an accuracy node at 3360fps, but clearly this gun likes that muzzle velocity regardless of what powder got it there.

Wow that is pretty cool.

 

[Nightraider]

Attached are 7 graphs of "group size vs velocity" for 7 different loads in a single rifle. The first 5 graphs are for a 117gn bullet, the last 2 graphs are for a 120gn bullet. Rifle is a Winchester M70 in .264WM. For most (but not all) of the loads, there is a consistent accuracy node at 3350-3370 fps from powder-to-powder and bullet-to-bullet. Not saying that others shooting a .264WM will find an accuracy node at 3360fps, but clearly this gun likes that muzzle velocity regardless of what powder got it there.

You're only looking at 1/2 of the equation. Once you have the foundation built, you have to build the house. You've only started the foundation here, seating depth builds the house.

 

[swd]

3 different rifles, 3 different cartridges, 6BRA, 6BRX and a Dasher all shooting 110SMK’s. All 3 rifles shoot within 20FPS for their best load. Some, if not many bullets definitely like a certain speed.