Council with the node

[100FUEGOS]

 

[100FUEGOS]

At the top node the bolt was sticky...

 

[CharlieNC]

What node? A linear trend with random noise is what you are seeing, what did the target show?

 

[6bra1k]

where is the target, bullet holes logged my shot number, all else is pretty much a waste of time and ammo

 

[tthomp302]

I would explore between 52.8 and 53.3.

 

[Orr89rocz]

I was gonna say 51.8-52.3

 

[100FUEGOS]

The doubt is there. In the middle of 52 and 53. The barrel only has 40 shots and when it releases, it will go to the upper node... I expect 100 feet of rise... And overpressure. That's why being conservative and waiting at 52 for him to release or 53 and whatever God wants... I plan for him to release in the middle of the competition.

 

[100FUEGOS]

kelbly por barril 32" 1:9 (scenar 180 latón Peterson)

 

[jelenko]

What do the numbers on the target represent? For instance, does 50.0 - 54.5 mean that all rounds with loads between and including 50.0 to 54.5 grains of powder went through the same hole?

 

[Ned Ludd]

As near as I can figure from the limited information provided, in terms of the velocity the 52.8 to 53.3 "flat spot" in the velocity curve is already much higher than most are getting with tuned loads using 180s (i.e. around 2850 fps). When you combine that with a barrel that hasn't "sped up" yet, and sticky bolt lift, the 52.8-53.3 gr region is probably not where you want to be. On the other hand, the 51.8-52.3 gr charge weight segment of the curve is well within the velocity region where you'd expect a load with 180s and a 32" barrel to tune in. Your expectation of a 100 fps velocity increase as the barrel laps in seems a bit excessive to me. My suggestion would be to proceed with the lower 51.8 gr charge weight and monitor velocity carefully as you put more rounds down the barrel. Once you have at least a couple hundred rounds through it, you'd likely be re-doing, or at least tweaking, the load anyhow.

 

[ebb]

When a barrel vibrates as it is fired it tends to go up and down mostly. So if the charge weight of the powder is altered the bullet will exit at different points in the barrel vibration cycle. I you will load a single casing with 52.5 grains of powder and shoot it at the target, then load another at 52.6 then 52.7 and shoot them at the same POI they should be getting higher or lower on the target. If you keep loading .1 grain higher soon you will stop going higher or lower and start going the other way. If you will continue doing this till you find the bottom and the top, those are the nodes. The barrel vibrates up and down like a pendulum on a clock. When the barrel gets close to the top or bottom is slows down and if you time the shots with the powder charge to be at the top or bottom, your group will get smaller than if they exited the barrel in the middle of its motion. The node is when the vibration cycle is at the top or bottom of the cycle.

 

[100FUEGOS]

 

[100FUEGOS]

Play freebore...

 

[100FUEGOS]

 

[100FUEGOS]

More information. Sampling the burn range... and looking for the best freebore.

 

[100FUEGOS]

 

[100FUEGOS]

More information. Sampling the burn range... and looking for the best freebore.

 

[100FUEGOS]

As near as I can figure from the limited information provided, in terms of the velocity the 52.8 to 53.3 "flat spot" in the velocity curve is already much higher than most are getting with tuned loads using 180s (i.e. around 2850 fps). When you combine that with a barrel that hasn't "sped up" yet, and sticky bolt lift, the 52.8-53.3 gr region is probably not where you want to be. On the other hand, the 51.8-52.3 gr charge weight segment of the curve is well within the velocity region where you'd expect a load with 180s and a 32" barrel to tune in. Your expectation of a 100 fps velocity increase as the barrel laps in seems a bit excessive to me. My suggestion would be to proceed with the lower 51.8 gr charge weight and monitor velocity carefully as you put more rounds down the barrel. Once you have at least a couple hundred rounds through it, you'd likely be re-doing, or at least tweaking, the load anyhow.

It's my general idea, but I needed to hear it.

 

[100FUEGOS]

When a barrel vibrates as it is fired it tends to go up and down mostly. So if the charge weight of the powder is altered the bullet will exit at different points in the barrel vibration cycle. I you will load a single casing with 52.5 grains of powder and shoot it at the target, then load another at 52.6 then 52.7 and shoot them at the same POI they should be getting higher or lower on the target. If you keep loading .1 grain higher soon you will stop going higher or lower and start going the other way. If you will continue doing this till you find the bottom and the top, those are the nodes. The barrel vibrates up and down like a pendulum on a clock. When the barrel gets close to the top or bottom is slows down and if you time the shots with the powder charge to be at the top or bottom, your group will get smaller than if they exited the barrel in the middle of its motion. The node is when the vibration cycle is at the top or bottom of the cycle.

When I referred to the node, I wanted to talk about the burning rate of the gunpowder according to its charge and the change in behavior or way of burning that it has...

 

[100FUEGOS]

Thank you all for your wisdom...
I speak out loud, to generate a point of discussion, where we can learn more... and those who are looking for can read us: why, when, where, who and what... the five W's of the reloading.