Pressure Traces from Jan. 19, 2011
Jan 20, 2011 16:21:33 GMT -5
Post by Richard on Jan 20, 2011 16:21:33 GMT -5
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Weather turned out sunny with little wind and temperatures went from 40* in the early morning to the mid 50's.
.45 cal.
The first two targets/Traces were as/per Edge's request: Shoot five shots on N-110 with no cleaning in between shots. From the work sheet you can see I went with 50 gr. of N-110, (always use the) smooth blue Harvester sabot along with the most inexpensive .40 jacketed bullet readily available...the 200 gr. XTP. This bullet was used for all six Traces today.
So, I load and fire the first shot from a cold barrel.........I am aiming at the upper left hand bull (now designated #2). The shot is no where to be found on the target board?? The chronograph gives me a good reading and the pressure trace looks good (especially after the next four shots). I scratch my head and just chalk if off to "whatever?". So now I reload and aim at the yellow piece of tape which I had put a black dot on (in the event I needed more targets ). Low and behold, the next four shot all form an average group??? Still can't figure out shot #1. NO cleaning for all shots following the first one. Bullet seating actually felt pretty much the same as when I clean between shots
Now for target #2 with the same load. I run my two patch light cleaning before loading. Since my original bull I was aiming at was "clean" I go the the upper left target. Fire the first shot..........Hmmm, way off the paper but still on the board??? Fire shot #2 and the same thing? Now I am dead certain I did not screw up..........Hmmmm. So, I check the lock nuts on the Burris tactical scope mounts and they are tight. The Farrel mount feels tight. I set the gun back in the rest and run the elevation and windage adjustments up and back about four clicks and everything seems to be moving and tracking?? Also, the velocities and pressures seem to be right in line. So I fire shots 3,4 & 5 and get a three shot 1.2" group similar to target #1??? I'm still confused but decide to move on. Of interest in these first two targets is this: The pressures and velocities stayed about the same for all ten shots...?
The next four targets were shot to compare four different primers with the same load........Head to head on the same day, with the same conditions. Not shooting one day and getting X results and then a month later shoot a different primer under different conditions and maybe getting a better group and saying: This primer is better, shoots tighter groups or whatever? Considering the conditions might have been better and your aim was better.
So here is the real deal: Federal 209's, CCI 209M's, Remington 209's and the primer I use ALL the time........Winchester 209's. The load is a duplex that has given me excellent results in the past: The same ole's 200 gr. XTP with 13 gr. of N-110 under 55 gr. of H-322. If you look closely at the results, you will see that Average five shot velocities had an extreme spread of only 6 fps The pressure varied only 873 psi which is nothing if you look at the past five weeks worth of traces. And, there was no big differences in the group sizes. Since these are not being fired from a "machine rest" with an electronic controlled trigger, human error exists.
While this might not be big sampling, I think it is safe for ME to say that whatever primer I use? It AIN'T gonna' make a difference. That is my opinion based on first hand shooting.
I have heard the same old story too many times that one primer is better than another. In a highly tuned accurate benchrest rifle with a shooter that can shoot? There might be a slight advantage with one vs. the other. In a ML...............? You will have to prove it to me because I saw no difference. When I got done with the shooting and showed the results to Herman..........He said: "There ain't no difference!" He shoots both Federal, CCI and Winchesters and never could tell the difference.
Richard
Weather turned out sunny with little wind and temperatures went from 40* in the early morning to the mid 50's.
.45 cal.
The first two targets/Traces were as/per Edge's request: Shoot five shots on N-110 with no cleaning in between shots. From the work sheet you can see I went with 50 gr. of N-110, (always use the) smooth blue Harvester sabot along with the most inexpensive .40 jacketed bullet readily available...the 200 gr. XTP. This bullet was used for all six Traces today.
So, I load and fire the first shot from a cold barrel.........I am aiming at the upper left hand bull (now designated #2). The shot is no where to be found on the target board?? The chronograph gives me a good reading and the pressure trace looks good (especially after the next four shots). I scratch my head and just chalk if off to "whatever?". So now I reload and aim at the yellow piece of tape which I had put a black dot on (in the event I needed more targets ). Low and behold, the next four shot all form an average group??? Still can't figure out shot #1. NO cleaning for all shots following the first one. Bullet seating actually felt pretty much the same as when I clean between shots
Now for target #2 with the same load. I run my two patch light cleaning before loading. Since my original bull I was aiming at was "clean" I go the the upper left target. Fire the first shot..........Hmmm, way off the paper but still on the board??? Fire shot #2 and the same thing? Now I am dead certain I did not screw up..........Hmmmm. So, I check the lock nuts on the Burris tactical scope mounts and they are tight. The Farrel mount feels tight. I set the gun back in the rest and run the elevation and windage adjustments up and back about four clicks and everything seems to be moving and tracking?? Also, the velocities and pressures seem to be right in line. So I fire shots 3,4 & 5 and get a three shot 1.2" group similar to target #1??? I'm still confused but decide to move on. Of interest in these first two targets is this: The pressures and velocities stayed about the same for all ten shots...?
The next four targets were shot to compare four different primers with the same load........Head to head on the same day, with the same conditions. Not shooting one day and getting X results and then a month later shoot a different primer under different conditions and maybe getting a better group and saying: This primer is better, shoots tighter groups or whatever? Considering the conditions might have been better and your aim was better.
So here is the real deal: Federal 209's, CCI 209M's, Remington 209's and the primer I use ALL the time........Winchester 209's. The load is a duplex that has given me excellent results in the past: The same ole's 200 gr. XTP with 13 gr. of N-110 under 55 gr. of H-322. If you look closely at the results, you will see that Average five shot velocities had an extreme spread of only 6 fps The pressure varied only 873 psi which is nothing if you look at the past five weeks worth of traces. And, there was no big differences in the group sizes. Since these are not being fired from a "machine rest" with an electronic controlled trigger, human error exists.
While this might not be big sampling, I think it is safe for ME to say that whatever primer I use? It AIN'T gonna' make a difference. That is my opinion based on first hand shooting.
I have heard the same old story too many times that one primer is better than another. In a highly tuned accurate benchrest rifle with a shooter that can shoot? There might be a slight advantage with one vs. the other. In a ML...............? You will have to prove it to me because I saw no difference. When I got done with the shooting and showed the results to Herman..........He said: "There ain't no difference!" He shoots both Federal, CCI and Winchesters and never could tell the difference.
Richard