Upper node???
- Thread starter Bro.D
- Start date
jackie schmidt
New member
Bro D
I do not know anything about that 120 fps node thing, I would think every bullet-barrel-powder combo would be different.
As for what is considered the upper node, I would say that with a typical 66-68 grn match bullet, 3380+ out of a 21 1/2 inch barrel would be in the upper node.......jackie
I do not know anything about that 120 fps node thing, I would think every bullet-barrel-powder combo would be different.
As for what is considered the upper node, I would say that with a typical 66-68 grn match bullet, 3380+ out of a 21 1/2 inch barrel would be in the upper node.......jackie
Yep....
This is why I ask. Last weekend I was shooting at Raton. Things were looking good. I felt like my gun was very close to tune, I was not seeing anything that would cause concern. For the fun of it I brought my Chrony. I realize it is a lower end unit but it has worked for me in the past. I set it up and shot my first round through it. I was amazed...it read 3500 fps. I though, that can't be. The gun shot fine, bolt lift was ok, I had shot this brass at least ten times and it was working fine.... I shot a few more and they fell right in that range. (3500 fps). If I remember right I shot about twenty rounds over the unit and they averaged 3494 fps. I concluded that my unit was reading fast and that there was no way I was reaching that vel. Another shooter came out and set up next to me. Just for the information I asked if I could put my Chrony in front of him and see what my unit read from his gun. His gun was shooting very well and his load read, if I remember right, 3300. That was about what he though he was shooting at which caused me to think, "Maybe my unit is reading ok." Ater that I started working on a lower node. Is 3500 fps possible out of a stock 6ppc? If it is, what kind of pressures would that take to reach that vel. Maybe I don't want to know. Michael, next time I wold like to shoot over a good chrony, just to know for sure.
This is why I ask. Last weekend I was shooting at Raton. Things were looking good. I felt like my gun was very close to tune, I was not seeing anything that would cause concern. For the fun of it I brought my Chrony. I realize it is a lower end unit but it has worked for me in the past. I set it up and shot my first round through it. I was amazed...it read 3500 fps. I though, that can't be. The gun shot fine, bolt lift was ok, I had shot this brass at least ten times and it was working fine.... I shot a few more and they fell right in that range. (3500 fps). If I remember right I shot about twenty rounds over the unit and they averaged 3494 fps. I concluded that my unit was reading fast and that there was no way I was reaching that vel. Another shooter came out and set up next to me. Just for the information I asked if I could put my Chrony in front of him and see what my unit read from his gun. His gun was shooting very well and his load read, if I remember right, 3300. That was about what he though he was shooting at which caused me to think, "Maybe my unit is reading ok." Ater that I started working on a lower node. Is 3500 fps possible out of a stock 6ppc? If it is, what kind of pressures would that take to reach that vel. Maybe I don't want to know. Michael, next time I wold like to shoot over a good chrony, just to know for sure.
Bro. D
You probably were at 3500. With Lapua brass this velocity isn't impossible. If 120 fps does seperate one node to another, then 3380 like Jackie said is spot on. But i also believe he is right about the nodes being different for different loads and barrels lengths. Some say this doesn't change. I'm no expert, but I just can't see it that way. If your chrony is off, then it would be by a percentage. If it is compared to a known good one. Then from now on, you can calculate the true speed. Anybody else seen these kind of velocities? Please let us know about an "upper" upper node. How was the case life?
Michael
You probably were at 3500. With Lapua brass this velocity isn't impossible. If 120 fps does seperate one node to another, then 3380 like Jackie said is spot on. But i also believe he is right about the nodes being different for different loads and barrels lengths. Some say this doesn't change. I'm no expert, but I just can't see it that way. If your chrony is off, then it would be by a percentage. If it is compared to a known good one. Then from now on, you can calculate the true speed. Anybody else seen these kind of velocities? Please let us know about an "upper" upper node. How was the case life?
Michael
Case life...
The case life seemed to be within reason. Before I set up the Chrony I had shot the brass probably ten times. They sized in my FL die fine. Extraction after firing was fine. After about 12 firings there was the bolt click at the top of the bolt throw but this too seemed within reason. Primer pockets still hold the primers and seating the primers goes just like always. The only sign of real pressure I have seen was when I examined the spent primers. They do have some cratering. Never a pierced primer, though. If nothing else this is a testimony to the quality actions out there today. Bro.D
The case life seemed to be within reason. Before I set up the Chrony I had shot the brass probably ten times. They sized in my FL die fine. Extraction after firing was fine. After about 12 firings there was the bolt click at the top of the bolt throw but this too seemed within reason. Primer pockets still hold the primers and seating the primers goes just like always. The only sign of real pressure I have seen was when I examined the spent primers. They do have some cratering. Never a pierced primer, though. If nothing else this is a testimony to the quality actions out there today. Bro.D
bryan
Bryan Armatys
That suckers' fast!
BroD: I wish I had my Oehler out there on Friday, but the last time I used it I got continual error messages. I'll try to figure it out and bring it to the match. My velocities seemed to be about right, maybe even a bit low, so yours were definately hot. Glad to see the lower velocity you throttled down to shot great as well.
Wanna sell some bullets?
Bryan
BroD: I wish I had my Oehler out there on Friday, but the last time I used it I got continual error messages. I'll try to figure it out and bring it to the match. My velocities seemed to be about right, maybe even a bit low, so yours were definately hot. Glad to see the lower velocity you throttled down to shot great as well.
Wanna sell some bullets?
Bryan