CCI subsonic40gr hp ES
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On RFC there is an ongoing and extensive thread that was begun in mid-2018 that compares many different ammos. Fifty rounds (a whole box) is tested at a time. While it includes a considerable number of CCI s varieties, 17 of them in all, some of them tested more than once, unfortunately it does not include the same CCI Subsonic HP ammo rated on the box at 1050 fps MV in question here. The thread from which the following information is taken, and which includes information for many varieties of match ammo as well as others, can be found here h t t p s://www.rimfirecentral.com/forums/showthread.php?t=1129343
CCI SV, MV rated at 1070 fps, was chronographed twice. The ES figures were 73 fps (high of 1092, low 1019) and 85 fps (high 1103, low 1018). Its one of the manufacturer's "Target and Plinking" varieties,
CCI Green Tag, which is one of the manufacturer's "Competition" varieties, has an MV rated at 1070 fps. Its ES was 104 fps (high 1152, low 1048).
CCI Pistol Match, another of the "Competition" varieties, also has an MV rated at 1070 fps. Its ES was 73 fps (high 1103, low 1030).
The best CCI product tested on the RFC thread appears to be CCI SGB, a 1235 fps box rated MV round with a flat point lead bullet. Its ES was 37 fps (high 1268, low 1231).
To add some perspective, some of the best ES figures achieved were with expensive match ammo. These included the likes of Eley Tenex, for example, which was tested three times in all. ES figures were 18 fps in one test, 45 fps in another, and 35 fps in a third. Eley Match was tested twice, with an ES of 17 fps in one test and 32 fps in another.
Of course Tenex and Match are expensive. Many shooters use Lapua Center X ammo, which is a little more affordable. Its ES results over two tests were 38 fps and 44 fps.
It is important to remember that these figures were obtained with the particular lots of ammo that were chronographed. Different lots will produce different results. This is true for all rimfire ammo. Some will have a lower ES than others, some will be higher. No one can know until what it will be until ammo from a lot in question is tested, and in statistically significant numbers. What that means is that any five or ten randomly selected rounds may have a very low ES or it might not. When 50 rounds are tested, a fuller picture of what's possible over a whole box becomes a little more clear.
CCI SV, MV rated at 1070 fps, was chronographed twice. The ES figures were 73 fps (high of 1092, low 1019) and 85 fps (high 1103, low 1018). Its one of the manufacturer's "Target and Plinking" varieties,
CCI Green Tag, which is one of the manufacturer's "Competition" varieties, has an MV rated at 1070 fps. Its ES was 104 fps (high 1152, low 1048).
CCI Pistol Match, another of the "Competition" varieties, also has an MV rated at 1070 fps. Its ES was 73 fps (high 1103, low 1030).
The best CCI product tested on the RFC thread appears to be CCI SGB, a 1235 fps box rated MV round with a flat point lead bullet. Its ES was 37 fps (high 1268, low 1231).
To add some perspective, some of the best ES figures achieved were with expensive match ammo. These included the likes of Eley Tenex, for example, which was tested three times in all. ES figures were 18 fps in one test, 45 fps in another, and 35 fps in a third. Eley Match was tested twice, with an ES of 17 fps in one test and 32 fps in another.
Of course Tenex and Match are expensive. Many shooters use Lapua Center X ammo, which is a little more affordable. Its ES results over two tests were 38 fps and 44 fps.
It is important to remember that these figures were obtained with the particular lots of ammo that were chronographed. Different lots will produce different results. This is true for all rimfire ammo. Some will have a lower ES than others, some will be higher. No one can know until what it will be until ammo from a lot in question is tested, and in statistically significant numbers. What that means is that any five or ten randomly selected rounds may have a very low ES or it might not. When 50 rounds are tested, a fuller picture of what's possible over a whole box becomes a little more clear.
It must be a fairly consistent ammo to shoot well however only one of my .22 really likes the stuff. I dont own a crono i just enjoy getting out and shooting. my tikka shoots it particularly well. i posted some ten shot groups at 50 yards do to all the skepticism, have a look and it doesn't hurt to buy a pack and try it out its 10.00 - 13.00 per 100rds most places.
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Varmint Hunter
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- Southern, Ont
I know that this isn't CCI SV but I wish to make a point on different rifles. I have a ruger precision rimfire. Federal match shoots the best in it. ES was mid 75 to 80 fps averaging 10 shot samples. Now the gun didn't shoot as good as I was looking for so I chucked it into the lathe shortened the chamber till I was engaged the bullets into the rifling and set the head space very tight. (Note I can hardly close the bolt on bulk ammo only target fits well because of the inconsistent rim thickness.....) I shot 3 boxes of 50 at 6 degrees yesterday ES was 35, 55, 52 SD was 7.5, 10.3, 11.3. 10-15 shot batches were 22 to 28 ES so dont forget there is definitely a difference in batch size as to what numbers you get. Also SD is a better way to compare consistency ES includes the flukes and can make good ammo look bad. Now what I'm driving at is yes some ammo is generally more consistent then others but what it did in my rifle doesn't say that in yours will be even similar results. This was the same barrel only chamber dimensions changed a match chamber should be more consistent all things being equal. Cheers
A good point by Varmint Hunter. The chronograph performance of any ammo will vary by lot and by rifle. That is to say, not all lots of a certain variety of ammo will be the same out of a given rifle; and not all rifles -- even those of the same make and model -- will produce the same chrono results with the same batch of ammo. The latter is because bores will differ between rifles, even of the same make and model, the former because lots differ from one another, despite having the same name on the box.
Further, in order to get the most reliable data when testing with a chrony, it is necessary to use as large a sample size as possible. Ten shots will reveal what those ten shots are like, not necessarily what a full box of 50 rounds will be like. Not everyone, of course, would want to shoot entire boxes of a particular ammo over a chronograph to get an idea of its performance. Complicating things further, no matter how many rounds are tested -- whether its ten, thirty, or more -- it is possible that the chrony results of any boxful of random rounds of ammo may not reflect the results that exist over an even larger sample of the same lot of ammo. In the end, several tests of a meaningful sample size should give a reasonable picture of the performance of a particular lot of ammo in a particular rifle.
Further, in order to get the most reliable data when testing with a chrony, it is necessary to use as large a sample size as possible. Ten shots will reveal what those ten shots are like, not necessarily what a full box of 50 rounds will be like. Not everyone, of course, would want to shoot entire boxes of a particular ammo over a chronograph to get an idea of its performance. Complicating things further, no matter how many rounds are tested -- whether its ten, thirty, or more -- it is possible that the chrony results of any boxful of random rounds of ammo may not reflect the results that exist over an even larger sample of the same lot of ammo. In the end, several tests of a meaningful sample size should give a reasonable picture of the performance of a particular lot of ammo in a particular rifle.
For my purposes ES and SD are irrelevant... all I care about is what "actually" shoots best on paper in "real world" shooting. You might have a batch of ammo with a relatively high ES that shoots better than a batch of ammo with a relatively low ES, out of any given rifle on any given day... rimfire is a strange and mystical beast... there are many, many factors that effect the ultimately achievable accuracy for a given rifle. Five decades of shooting rimfire has me convinced that crunching numbers is just not where it is at, squeezing triggers is where it is at. Just my two cents.
For what it is worth, as it turns out, the most accurate ammo I tested in my current hunting rifle is CCI Subsonic HP.
For what it is worth, as it turns out, the most accurate ammo I tested in my current hunting rifle is CCI Subsonic HP.
While knowing what MV results are with a certain rifle and ammo doesn't change a thing down range on the target, it can be useful to understand why some ammo behaves as it does. It may be true that to a small extent some barrels seem less responsive to ammo with a higher ES than other barrels. Why? The reasons relate to barrel harmonics (how a particular barrel vibrates), which in turn are linked to barrel dimensions. Nevertheless, without involving a tuner, and in the same barrel, slower ammo tends to have a lower POI than ammo that has a higher MV. Of course not all barrels are alike and no barrel can overcome what is demanded by physics. In the end, despite what is often difficult or seemingly impossible to understand, rimfire shooting behaviour is never so capricious as to defy physical laws utterly and completely. Nothing but miracles can do that.
Without a chronograph it is impossible to know the average MV or muzzle velocity of a box of ammo. The information printed on a box of ammo is the average the ammo is designed to achieve when tested by the manufacturer in its particular barrels. It's equally impossible to know the ES or extreme spread -- the difference between the fastest and slowest ammo in the sample -- without a chronograph. And without chronograph data it's impossible to know what the SD -- standard deviation -- of the ammo is.
While MV and ES are not unimportant, the SD is probably the most useful information a shooter can have about his ammo. Standard deviation indicates how close to the average MV the majority of the ammo in question actually is. An ES of 40 fps is not bad in itself, but if the majority of individual rounds have an actual MV closer to both the high end and the low end of the ES then that ammo is less desirable than a batch of ammo that has most of the individual rounds much closer to the average MV but with a few outliers producing the ES figure.
In short, the lower the SD the better. Unfortunately, shooters can't know the SD until it has been calculated after chronographing the ammo. An exceptionally low SD for .22LR ammo would be around 5 but figures between 10 and 15 can still be useful for target ammo. Higher SD's are not uncommon with many makes of ammo, even with match ammos.
To illustrate standard deviation, an SD of 10 means that two-thirds (roughly 68%) of the ammo in that particular batch will shoot within 10 fps (plus or minus) of the average muzzle velocity. That means an ES for that ammo of 20 fps for that two-thirds of the ammo. The remaining third, that is every one out of three rounds, will have an even higher or lower MV.
Nevertheless all of this remains irrelevant to many rimfire shooters. Most of them don't chronograph the ammo they use and that's understandable. It's an extra cost and can be very tedious. If a shooter is interested simply in seeing what happens, then MV, ES, and SD is all hooey. Knowing that stuff doesn't change a thing down range on the target. For those interested in achieving the best accuracy possible, however, it does matter. While most of these shooters also don't use a chronograph, at least not regularly, it is very useful to understand something about why the ammo they use behaves as it does.
Without a chronograph it is impossible to know the average MV or muzzle velocity of a box of ammo. The information printed on a box of ammo is the average the ammo is designed to achieve when tested by the manufacturer in its particular barrels. It's equally impossible to know the ES or extreme spread -- the difference between the fastest and slowest ammo in the sample -- without a chronograph. And without chronograph data it's impossible to know what the SD -- standard deviation -- of the ammo is.
While MV and ES are not unimportant, the SD is probably the most useful information a shooter can have about his ammo. Standard deviation indicates how close to the average MV the majority of the ammo in question actually is. An ES of 40 fps is not bad in itself, but if the majority of individual rounds have an actual MV closer to both the high end and the low end of the ES then that ammo is less desirable than a batch of ammo that has most of the individual rounds much closer to the average MV but with a few outliers producing the ES figure.
In short, the lower the SD the better. Unfortunately, shooters can't know the SD until it has been calculated after chronographing the ammo. An exceptionally low SD for .22LR ammo would be around 5 but figures between 10 and 15 can still be useful for target ammo. Higher SD's are not uncommon with many makes of ammo, even with match ammos.
To illustrate standard deviation, an SD of 10 means that two-thirds (roughly 68%) of the ammo in that particular batch will shoot within 10 fps (plus or minus) of the average muzzle velocity. That means an ES for that ammo of 20 fps for that two-thirds of the ammo. The remaining third, that is every one out of three rounds, will have an even higher or lower MV.
Nevertheless all of this remains irrelevant to many rimfire shooters. Most of them don't chronograph the ammo they use and that's understandable. It's an extra cost and can be very tedious. If a shooter is interested simply in seeing what happens, then MV, ES, and SD is all hooey. Knowing that stuff doesn't change a thing down range on the target. For those interested in achieving the best accuracy possible, however, it does matter. While most of these shooters also don't use a chronograph, at least not regularly, it is very useful to understand something about why the ammo they use behaves as it does.
A test of a box of CCI MiniMags RN had a spread of 4 fps for five rounds and the group was 3/4" at 100 yards.
The next 5-shot was 1.75 and the first three were like the previous(about .5") then there was a drop in both velocity and impact for #4 and even more for #5.
While it looked promising a check of my stock showed this was all that remained . . . 35 rounds.
Some Chrony testing of my go to ammo, Remington Eley Match 1062 velocity and Federal match 922A is planned.
The next 5-shot was 1.75 and the first three were like the previous(about .5") then there was a drop in both velocity and impact for #4 and even more for #5.
While it looked promising a check of my stock showed this was all that remained . . . 35 rounds.
Some Chrony testing of my go to ammo, Remington Eley Match 1062 velocity and Federal match 922A is planned.
