Pressure Traces…..Week Five
Jan 13, 2011 11:07:27 GMT -5
Post by Richard on Jan 13, 2011 11:07:27 GMT -5
DISCUSSION THREAD CAN BE FOUND BY FOLLOWING THIS LINK
Pressure Traces…..Week Five
.45 cal.
Well, today the range was again, completely covered with fresh snow and the temperatures started at 23* and never got above 32*. The propane, kerosene and electric heaters, however, keep Bill and I at around the mid-50* mark. Herman got sick at our Saturday 600 yard match and sat the day out L. Most of what I tested today were comparisons. This way conclusions could be drawn under identical or very similar conditions. It was a bit windy today (left to right) so accuracy might not be right on, but close!
#1 Last week I shot 55 gr. Of N-110 behind a 200 XTP. This week I put 55 gr. Of 5744 behind the same bullet. Buzz in the past has always been that both powders produce about the same velocity. Maybe in the past this might have been the case but not today. Velocity was almost 200 fps slower and pressure about 2,000 psi lower.
#2 was just to show a comparison between 55 gr. And 70 gr. See below.
#3 & #4 were two single powder charges of 70 gr. These powders I typically use in conjunction with duplex loads although some have used them as singles. H-322 is about 200 fps faster than AA2015. Surprisingly, 2015 produced more pressure than 322 but less velocity?
#5 was another triplex changing the amounts of powder to 20 gr. across the board. Definitely a felt difference in recoil as compared to single powder loads of that velocity. Again, Bill commented at my first shot how much difference the shot sounded. And no, the accuracy was nothing to write home about but not awful? Considering the wind. Again, these powders and amounts need to vary as do the types. I should have also shot 70 gr. Of N-130 to add to #3&4 above.
Here is the logic I use when putting these loads together: I know, for example, that I can easily shoot 55 gr. Of N-110 with no adverse effects. I also know N-120 at that amount is very safe and N-130 is really slow, much like H-322 and 2015. There for, ANY mixing of these three powders totaling 60 gr. has to be less pressure/velocity than say 60 gr. of straight N-110. So when I put loads together I use this information to keep things safe……at least in my mind. Your mileage may varyJ
#’s 6, 7 & 8 are all 10/60 duplexes. The “10” being ten gr. Of N-110.………The other three are 60 gr. Of N-130, H-322 and AA2015. Totaling 70 gr………..Re: # 3 & # 4. N-130 and H-322 were more or less in the same ball park but AA2015 was slower. N-130 still being the fastest.
# 9 was a comparison of another 70 gr. Load using N-110 and H-322 but in different amounts. This is the load that has shot well for me from the beginning. It is also the load Herman’s friend shot a few weeks ago and posted a three shot ¾” 300 yard group with.
Until such time as this computer, ignorant, person can figure out how to convert these trace files to JPG’s ( and yes, Edge sent me a description but it does not seem to work or I’m not getting it?) I have to photograph the screen. Some times they come clearer than others and sometimes not! They look better at a higher resolution and then when I reduce them to fit our format, the lines from the flat screen show up? But I think they are readable.
Note: As opposed to the other traces in the past, I have set the screen at 3 miliseconds for a broader view.
Richard
Pressure Traces…..Week Five
.45 cal.
Well, today the range was again, completely covered with fresh snow and the temperatures started at 23* and never got above 32*. The propane, kerosene and electric heaters, however, keep Bill and I at around the mid-50* mark. Herman got sick at our Saturday 600 yard match and sat the day out L. Most of what I tested today were comparisons. This way conclusions could be drawn under identical or very similar conditions. It was a bit windy today (left to right) so accuracy might not be right on, but close!
#1 Last week I shot 55 gr. Of N-110 behind a 200 XTP. This week I put 55 gr. Of 5744 behind the same bullet. Buzz in the past has always been that both powders produce about the same velocity. Maybe in the past this might have been the case but not today. Velocity was almost 200 fps slower and pressure about 2,000 psi lower.
#2 was just to show a comparison between 55 gr. And 70 gr. See below.
#3 & #4 were two single powder charges of 70 gr. These powders I typically use in conjunction with duplex loads although some have used them as singles. H-322 is about 200 fps faster than AA2015. Surprisingly, 2015 produced more pressure than 322 but less velocity?
#5 was another triplex changing the amounts of powder to 20 gr. across the board. Definitely a felt difference in recoil as compared to single powder loads of that velocity. Again, Bill commented at my first shot how much difference the shot sounded. And no, the accuracy was nothing to write home about but not awful? Considering the wind. Again, these powders and amounts need to vary as do the types. I should have also shot 70 gr. Of N-130 to add to #3&4 above.
Here is the logic I use when putting these loads together: I know, for example, that I can easily shoot 55 gr. Of N-110 with no adverse effects. I also know N-120 at that amount is very safe and N-130 is really slow, much like H-322 and 2015. There for, ANY mixing of these three powders totaling 60 gr. has to be less pressure/velocity than say 60 gr. of straight N-110. So when I put loads together I use this information to keep things safe……at least in my mind. Your mileage may varyJ
#’s 6, 7 & 8 are all 10/60 duplexes. The “10” being ten gr. Of N-110.………The other three are 60 gr. Of N-130, H-322 and AA2015. Totaling 70 gr………..Re: # 3 & # 4. N-130 and H-322 were more or less in the same ball park but AA2015 was slower. N-130 still being the fastest.
# 9 was a comparison of another 70 gr. Load using N-110 and H-322 but in different amounts. This is the load that has shot well for me from the beginning. It is also the load Herman’s friend shot a few weeks ago and posted a three shot ¾” 300 yard group with.
Until such time as this computer, ignorant, person can figure out how to convert these trace files to JPG’s ( and yes, Edge sent me a description but it does not seem to work or I’m not getting it?) I have to photograph the screen. Some times they come clearer than others and sometimes not! They look better at a higher resolution and then when I reduce them to fit our format, the lines from the flat screen show up? But I think they are readable.
Note: As opposed to the other traces in the past, I have set the screen at 3 miliseconds for a broader view.
Richard