In follow up to a couple of my posts that I've done testing the BC's for several pellets for my gun (RAW HM1000x) in .25 and .30 caliber, and more recently for testing the BC's in my son's FX Wildcat Mk II I was given the opportunity to test the Rat Sniper slugs thanks to a generous gift from fellow forum member crgabel. Tonight I was able to get out and collect some BC data on the slugs vs. JSB Mk II Heavy pellets (all in .25 cal), and the results are simply jawdropping!
Method:
All pellets (and slugs) were not measured and were taken straight out of the tin without sorting for weight. No sorting for head sizes was complete either-so accuracy and variability are what you will typically experience shooting straight out of the tin.
Muzzle velocity, near was taken with the rear window of the chrony at 1 yard (3') from the tip of the moderator. Distance to far measurement, was taken with the rear window of the chrony at 50 yard from the tip of the moderator Delta (distance) between locations: 49 yards (measured with a Nikon laser rangefinder with angle compensation)
The pictures below are for illustration purposes and are from earlier in the year.
Setup @ 1 yard: (Note: Photos show the Shooting Chrony, Beta unit-but I now use the Caldwell unit up close to automatically record data.
Setup at the target (@ 50 yards, a 49 yard delta):
The weather today was beautiful: average temp today was 85-87F, with nearly calm winds (2 mph out of the N), 56% Humidity, pressure at 29.90 in Hg.
Tested gun: RAW HM1000x in .25 caliber with LW polygon barrel and stock RAW moderator (see photo above). Gun was bench rested and aimed at the same spot on the target to maximize consistency of results.
After recording the data (using the App for the Caldwell, reading/writing the shot results from the Shooting Chrony @ 50 yards) I opened up Chairgun (Mac version) and adjusted the environmental conditions, altitude, etc. I then went to the BC calculator app, plugged in the data, and calculated the following results (below).
Test notes: Two different Chronographs were used (they have been carefully compared to find the offset in velocity readings between the two): the 1 yard chrony used is the 'Caldwell Ballistic Precision' Chronograph with the data link to the iPhone app to automatically record the shot data. The 50 yard chrony used is the 'Shooting Chrony, Beta' Chronograph and the data was recorded manually after each shot (entered into a spreasheet, shot by shot) for the shot data from that chrony. The offset between my two chrony's has been determined through painstaking testing to be 'Caldwell Velocity = Shooting Chrony Beta Velocity + 8.4 fps' (in other words: you have to add 8.4 fps to the Beta to equal the velocity measured by the Caldwell). These two distances have become my standard for recording BC data for airguns as the 1 yard 'muzzle' distance allows most of the exit dynamics to settle down and the 50 yard gives a good indication of typical target distances at longer range for which the guns will be used.
Velocity data is shown below.
Shooter: me.
I initially set off to shoot enough shots to obtain 10 rounds of data, but was quickly losing daylight, and the lighter Slug (31.5 grain) seemed to be to widespread of a pattern for consistently recording at 50 yards. In this instance I had to gather whatever data I could, and I had a very limited number of slugs available to test so I apologize for the low sample size on the RatSniper 31.5 grain pellets. What I can say, however, is that the two RatSnipers shot very tight spreads (across the 1 yard Chrony) and the results from the 36 grain slugs at 50 yards showed consistent spreads as well.
I did map the velocities, shot to shot, in groupings, but then averaged the bunch from both locations to use as inputs to calculate the BC's using Chairgun. For those inclined to ask: yes, I have done it the other way in the past mapping the BC-shot by shot-since I have the data for a single pellet across both chronies. What I end up getting is a chart that shows some variability in the BC results and, when averaged, end up matching the results of simply averaging the data from the near chrony, averaging the data from the far chrony, and then using those two velocities with the delta distance to calculate the BC. The BC's end up being the same either way...
Phase II of this comparison will be to shoot 5 shot groups at 50 yards. Once I obtain more slugs, I can extend that out to 100 yards, or further, if that makes sense.
First up: JSB Heavies, Mk I (33.95 grn): [Note: previous results with similar environmental conditions showed a BC of 0.0566, for reference]
[Note: Form factor for BC calculations most closely matches the GA form for a Diabolo pellet shap, so that is what is used for the JSB Pellets.]
Shot group:
(Picture may be added later)
Next up: RatSniper Lite Slugs (31.5 grn):
[Note: Form factor for BC calculations most closely matches the G1 form, so that is what is used for the slugs.]
Shot group:
(Picture may be added later)
Next up: RatSniper Heavy Slugs (36.0 grn):
[Note: Form factor for BC calculations most closely matches the G1 form, so that is what is used for the slugs.]
Shot group:
(Picture may be added later)
Yes, you read those correctly!!! I knew the instance I was seeing the 50 yard velocities that these BC's were through the roof compared to even the best pellets I've shot to date!
Note: In the past I've included photos of the shot groups, measured for group size, etc. I plan to do that as a seperate activity when I can focus solely on shooting groups without fear of hitting my 50 yard chrony (not that it has EVER happened before, LOL...).
And the raw data, summarized in chart form :
Please ask if you have any questions (or point out any typos). I hope you find this info helpful? Is so, please consider taking a second and simply leaving a '+' with a nice comment for me-it let's me know my time and effort is appreciated and keeps me going with this kind of work for the community.
Sean
Method:
All pellets (and slugs) were not measured and were taken straight out of the tin without sorting for weight. No sorting for head sizes was complete either-so accuracy and variability are what you will typically experience shooting straight out of the tin.
Muzzle velocity, near was taken with the rear window of the chrony at 1 yard (3') from the tip of the moderator. Distance to far measurement, was taken with the rear window of the chrony at 50 yard from the tip of the moderator Delta (distance) between locations: 49 yards (measured with a Nikon laser rangefinder with angle compensation)
The pictures below are for illustration purposes and are from earlier in the year.
Setup @ 1 yard: (Note: Photos show the Shooting Chrony, Beta unit-but I now use the Caldwell unit up close to automatically record data.
Setup at the target (@ 50 yards, a 49 yard delta):
The weather today was beautiful: average temp today was 85-87F, with nearly calm winds (2 mph out of the N), 56% Humidity, pressure at 29.90 in Hg.
Tested gun: RAW HM1000x in .25 caliber with LW polygon barrel and stock RAW moderator (see photo above). Gun was bench rested and aimed at the same spot on the target to maximize consistency of results.
After recording the data (using the App for the Caldwell, reading/writing the shot results from the Shooting Chrony @ 50 yards) I opened up Chairgun (Mac version) and adjusted the environmental conditions, altitude, etc. I then went to the BC calculator app, plugged in the data, and calculated the following results (below).
Test notes: Two different Chronographs were used (they have been carefully compared to find the offset in velocity readings between the two): the 1 yard chrony used is the 'Caldwell Ballistic Precision' Chronograph with the data link to the iPhone app to automatically record the shot data. The 50 yard chrony used is the 'Shooting Chrony, Beta' Chronograph and the data was recorded manually after each shot (entered into a spreasheet, shot by shot) for the shot data from that chrony. The offset between my two chrony's has been determined through painstaking testing to be 'Caldwell Velocity = Shooting Chrony Beta Velocity + 8.4 fps' (in other words: you have to add 8.4 fps to the Beta to equal the velocity measured by the Caldwell). These two distances have become my standard for recording BC data for airguns as the 1 yard 'muzzle' distance allows most of the exit dynamics to settle down and the 50 yard gives a good indication of typical target distances at longer range for which the guns will be used.
Velocity data is shown below.
Shooter: me.
I initially set off to shoot enough shots to obtain 10 rounds of data, but was quickly losing daylight, and the lighter Slug (31.5 grain) seemed to be to widespread of a pattern for consistently recording at 50 yards. In this instance I had to gather whatever data I could, and I had a very limited number of slugs available to test so I apologize for the low sample size on the RatSniper 31.5 grain pellets. What I can say, however, is that the two RatSnipers shot very tight spreads (across the 1 yard Chrony) and the results from the 36 grain slugs at 50 yards showed consistent spreads as well.
I did map the velocities, shot to shot, in groupings, but then averaged the bunch from both locations to use as inputs to calculate the BC's using Chairgun. For those inclined to ask: yes, I have done it the other way in the past mapping the BC-shot by shot-since I have the data for a single pellet across both chronies. What I end up getting is a chart that shows some variability in the BC results and, when averaged, end up matching the results of simply averaging the data from the near chrony, averaging the data from the far chrony, and then using those two velocities with the delta distance to calculate the BC. The BC's end up being the same either way...
Phase II of this comparison will be to shoot 5 shot groups at 50 yards. Once I obtain more slugs, I can extend that out to 100 yards, or further, if that makes sense.
First up: JSB Heavies, Mk I (33.95 grn): [Note: previous results with similar environmental conditions showed a BC of 0.0566, for reference]
[Note: Form factor for BC calculations most closely matches the GA form for a Diabolo pellet shap, so that is what is used for the JSB Pellets.]
Shot group:
(Picture may be added later)
Next up: RatSniper Lite Slugs (31.5 grn):
[Note: Form factor for BC calculations most closely matches the G1 form, so that is what is used for the slugs.]
Shot group:
(Picture may be added later)
Next up: RatSniper Heavy Slugs (36.0 grn):
[Note: Form factor for BC calculations most closely matches the G1 form, so that is what is used for the slugs.]
Shot group:
(Picture may be added later)
Yes, you read those correctly!!! I knew the instance I was seeing the 50 yard velocities that these BC's were through the roof compared to even the best pellets I've shot to date!
Note: In the past I've included photos of the shot groups, measured for group size, etc. I plan to do that as a seperate activity when I can focus solely on shooting groups without fear of hitting my 50 yard chrony (not that it has EVER happened before, LOL...).
And the raw data, summarized in chart form :
Please ask if you have any questions (or point out any typos). I hope you find this info helpful? Is so, please consider taking a second and simply leaving a '+' with a nice comment for me-it let's me know my time and effort is appreciated and keeps me going with this kind of work for the community.
Sean
