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Why is target ammunition subsonic?
- Thread starter Atticum
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Re: Why is target ammunition subsonic?
Breaking the sound barrier screws w/ bullet flight.
To do it twice before it gets to the target is generaly construed to be a bad thing.
Cheers,
Doc
Breaking the sound barrier screws w/ bullet flight.
To do it twice before it gets to the target is generaly construed to be a bad thing.
Cheers,
Doc
Re: Why is target ammunition subsonic?
a light bulb went off in my head the other day. if you drive a truck or car on the highway at 65-70 mph your vehicle blows all around. when you slow down, there is less drifting on the road. i guess the same princple holds true for the ammo.
plus there's the transsonic thing with the bullet hitting and dropping out of the sound barrier which destabilizes it and makes it wobble.
a light bulb went off in my head the other day. if you drive a truck or car on the highway at 65-70 mph your vehicle blows all around. when you slow down, there is less drifting on the road. i guess the same princple holds true for the ammo.
plus there's the transsonic thing with the bullet hitting and dropping out of the sound barrier which destabilizes it and makes it wobble.
Re: Why is target ammunition subsonic?
plus there's the transsonic thing with the bullet hitting and dropping out of the sound barrier which destabilizes it and makes it wobble.
Yeah, what he said
plus there's the transsonic thing with the bullet hitting and dropping out of the sound barrier which destabilizes it and makes it wobble.
Yeah, what he said
Re: Why is target ammunition subsonic?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cinosbus</div><div class="ubbcode-body">Wind drift is less with a subsonic .22lr too. </div></div>
More speed = less time to target = less time for wind to effect the path of the round.
Unless you are telling me that .22LR's somehow circumvent physics.
Match ammo is subsonic to avoid the instability caused by going trans-sonic.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: cinosbus</div><div class="ubbcode-body">Wind drift is less with a subsonic .22lr too. </div></div>
More speed = less time to target = less time for wind to effect the path of the round.
Unless you are telling me that .22LR's somehow circumvent physics.
Match ammo is subsonic to avoid the instability caused by going trans-sonic.
Re: Why is target ammunition subsonic?
Bullet does not transect the sonic barrier twice in flight, it goes supersonic inside the berrel.
Greg
Bullet does not transect the sonic barrier twice in flight, it goes supersonic inside the berrel.
Greg
Re: Why is target ammunition subsonic?
Does not circumvent physics , Believe it or not ? Subsonic just does it ' Way More Efficiently '.
It was explained to me a few years back and I was shown the #'s to back it up . ( ok this is Basically and roughly roundabout ). for example , ( 2 bullets of the same weight ) One is traveling 1070 fps. The other bullet of the same weight has to travel more than 1-k fps.more in Vel. to equal and start to surpass Windhold. of the projectile that is traveling Subsonic down range .
This is a rough explanation and I don't have the #'s to post. Maybe someone who is more booksmart than I, can post them up ?
.
Does not circumvent physics , Believe it or not ? Subsonic just does it ' Way More Efficiently '.
It was explained to me a few years back and I was shown the #'s to back it up . ( ok this is Basically and roughly roundabout ). for example , ( 2 bullets of the same weight ) One is traveling 1070 fps. The other bullet of the same weight has to travel more than 1-k fps.more in Vel. to equal and start to surpass Windhold. of the projectile that is traveling Subsonic down range .
This is a rough explanation and I don't have the #'s to post. Maybe someone who is more booksmart than I, can post them up ?
.
Re: Why is target ammunition subsonic?
Sub Sonic
With sub sonic ammo it is not the time of flight that comes into the equasion with regards to drift it is actualy the diference in loss of velocity between the two loads. The high velocity 22 ammo looses a higher percentage of velocity than the sub sonic or target loads. Also when projectiles go transonic things can happen. This is also why if you shoot a whisper you will actualy have less drift with heavy round nose projectiles than VLD projectiles one is designed for above the speed of sound the other works better below the speed of sound.
Just look at it like this it just is.
Sub Sonic
With sub sonic ammo it is not the time of flight that comes into the equasion with regards to drift it is actualy the diference in loss of velocity between the two loads. The high velocity 22 ammo looses a higher percentage of velocity than the sub sonic or target loads. Also when projectiles go transonic things can happen. This is also why if you shoot a whisper you will actualy have less drift with heavy round nose projectiles than VLD projectiles one is designed for above the speed of sound the other works better below the speed of sound.
Just look at it like this it just is.
Re: Why is target ammunition subsonic?
-The powder charge required to push higher velocities is not as linear in regards to MV and SD. I agree if super-sonic, it leaves that at the bore, it has to.
-22RF pills are short and lossy. It's box ammo. It is still rimfire with inherent variance in flash and power burn propagation. Less powder, longer pill & deeper seat = more consistant MV.
-It is intended for short range where this is advantagious. There are no concerns for transonic with either (LR or sub).
TOF is way less of a concern vs. the other variables at intended range. It prints better in mass production at close range.
Perhaps pill behavior/distortion in the bore with less push for a non-jacketed pill; especially with tapered bore at the muzzle. Not sure on that.
-The powder charge required to push higher velocities is not as linear in regards to MV and SD. I agree if super-sonic, it leaves that at the bore, it has to.
-22RF pills are short and lossy. It's box ammo. It is still rimfire with inherent variance in flash and power burn propagation. Less powder, longer pill & deeper seat = more consistant MV.
-It is intended for short range where this is advantagious. There are no concerns for transonic with either (LR or sub).
TOF is way less of a concern vs. the other variables at intended range. It prints better in mass production at close range.
Perhaps pill behavior/distortion in the bore with less push for a non-jacketed pill; especially with tapered bore at the muzzle. Not sure on that.
Re: Why is target ammunition subsonic?
Transonic range is technically between mach .75 and 1.20, so whether it's subsonic or supersonic, pretty much all .22lr exits the muzzle transonic.
In the upper transonic region, drag increases disproportionately higher than the velocity increases. This means a lower effective BC and increased wind drift in that velocity range.
The algorithms in ballistics programs do take this into account, so just punch in the numbers and see for yourself.
Transonic range is technically between mach .75 and 1.20, so whether it's subsonic or supersonic, pretty much all .22lr exits the muzzle transonic.
In the upper transonic region, drag increases disproportionately higher than the velocity increases. This means a lower effective BC and increased wind drift in that velocity range.
The algorithms in ballistics programs do take this into account, so just punch in the numbers and see for yourself.
Re: Why is target ammunition subsonic?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kombar</div><div class="ubbcode-body">Transonic range is technically between mach .75 and 1.20, so whether it's subsonic or supersonic, pretty much all .22lr exits the muzzle transonic.
In the upper transonic region, drag increases disproportionately higher than the velocity increases. This means a lower effective BC and increased wind drift in that velocity range.
The algorithms in ballistics programs do take this into account, so just punch in the numbers and see for yourself. </div></div>
The sonic envelope varies with condition. The bullet is not going to gain velocity after the crown. After the pill escapes the bore the following gases change condition even more for some computer judgement. Simple audible crack makes for conclusion.
Ignore sonic transition, TOF, BC; it's a 50m pill with best consistant MV and more forgiving in any animal.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Kombar</div><div class="ubbcode-body">Transonic range is technically between mach .75 and 1.20, so whether it's subsonic or supersonic, pretty much all .22lr exits the muzzle transonic.
In the upper transonic region, drag increases disproportionately higher than the velocity increases. This means a lower effective BC and increased wind drift in that velocity range.
The algorithms in ballistics programs do take this into account, so just punch in the numbers and see for yourself. </div></div>
The sonic envelope varies with condition. The bullet is not going to gain velocity after the crown. After the pill escapes the bore the following gases change condition even more for some computer judgement. Simple audible crack makes for conclusion.
Ignore sonic transition, TOF, BC; it's a 50m pill with best consistant MV and more forgiving in any animal.
Re: Why is target ammunition subsonic?
The issues are not cut and dried. How well a bullet retains its heading following transonic deceleration is a product of several factors, but the key here is that some shapes and C/G's manage the transition better. Unfortunately the .22LR design is not one of the best.
This is something that folks need to simply note and move on. Nothing can be done to change it, so discussion and conjecture will not improve the situation. It is what it is, and will remain so as long as rimfire bullet technology continues to stagnate the way it has for well over a century.
Me, I'll choose other windmills to tilt at, and simply enjoy the fact that the ammo does as well as it does.
In the end, we need to stop talking the problem and simply shoot through it. For what we have, we could be doing a lot worse, they could have loaded the cases with round balls.
Greg
The issues are not cut and dried. How well a bullet retains its heading following transonic deceleration is a product of several factors, but the key here is that some shapes and C/G's manage the transition better. Unfortunately the .22LR design is not one of the best.
This is something that folks need to simply note and move on. Nothing can be done to change it, so discussion and conjecture will not improve the situation. It is what it is, and will remain so as long as rimfire bullet technology continues to stagnate the way it has for well over a century.
Me, I'll choose other windmills to tilt at, and simply enjoy the fact that the ammo does as well as it does.
In the end, we need to stop talking the problem and simply shoot through it. For what we have, we could be doing a lot worse, they could have loaded the cases with round balls.
Greg
Re: Why is target ammunition subsonic?
a whole bunch of info for ya there. if any doubt shoot the HV and decent match stuff back to back on a calm day at 100 yards, then go out and do it again on a windy day at 100 yards. you'll see that whether all the answers you got make sense to you or not, or if it's some kind of "voodoo", the good target / match subsonic stuff just seems to work.
a whole bunch of info for ya there. if any doubt shoot the HV and decent match stuff back to back on a calm day at 100 yards, then go out and do it again on a windy day at 100 yards. you'll see that whether all the answers you got make sense to you or not, or if it's some kind of "voodoo", the good target / match subsonic stuff just seems to work.
Re: Why is target ammunition subsonic?
Anybody ever see a supersonic jet with a round nose? There is a reason that high speed bullets have a spitzer shape to them. The 22 was never designed for stability at supersonic speeds. The bullet shape prevents it. It's not the fact of being supersonic alone. Unless someone decided to redesign the 22 LR completely, the cheapest way to solve the problem is to keep match ammo subsonic. There is no reason to take more expensive remedies since the match ranges are so short.
teryx
Anybody ever see a supersonic jet with a round nose? There is a reason that high speed bullets have a spitzer shape to them. The 22 was never designed for stability at supersonic speeds. The bullet shape prevents it. It's not the fact of being supersonic alone. Unless someone decided to redesign the 22 LR completely, the cheapest way to solve the problem is to keep match ammo subsonic. There is no reason to take more expensive remedies since the match ranges are so short.
teryx
Re: Why is target ammunition subsonic?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Teryx</div><div class="ubbcode-body">Anybody ever see a supersonic jet with a round nose? There is a reason that high speed bullets have a spitzer shape to them. The 22 was never designed for stability at supersonic speeds. The bullet shape prevents it. It's not the fact of being supersonic alone. Unless someone decided to redesign the 22 LR completely, the cheapest way to solve the problem is to keep match ammo subsonic. There is no reason to take more expensive remedies since the match ranges are so short.
teryx </div></div>
This post really sums it up the best. It's the same reason that target pistols shoot wad cutter bullets. At the short ranges they are fired from, there is no gain in going to a higher velocity. Instead keeping a sub-sonic projectile at high uniformity it more impoertant.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Teryx</div><div class="ubbcode-body">Anybody ever see a supersonic jet with a round nose? There is a reason that high speed bullets have a spitzer shape to them. The 22 was never designed for stability at supersonic speeds. The bullet shape prevents it. It's not the fact of being supersonic alone. Unless someone decided to redesign the 22 LR completely, the cheapest way to solve the problem is to keep match ammo subsonic. There is no reason to take more expensive remedies since the match ranges are so short.
teryx </div></div>
This post really sums it up the best. It's the same reason that target pistols shoot wad cutter bullets. At the short ranges they are fired from, there is no gain in going to a higher velocity. Instead keeping a sub-sonic projectile at high uniformity it more impoertant.
Re: Why is target ammunition subsonic?
A HV 22LR starts out supersonic (from a rifle), and by 50 or so yards goes subsonic. Every notice how even on windless days, group sizes at 100 yards are more than twice the size of that at 50 yards? Some of that is the buffet as it drops below the Mach. Crappy BC's probably also have something to do with it as well.
If you want supersonic, go CCI Velocitor or 22WMR. Velocitor is supersonic at 100 yards.
A HV 22LR starts out supersonic (from a rifle), and by 50 or so yards goes subsonic. Every notice how even on windless days, group sizes at 100 yards are more than twice the size of that at 50 yards? Some of that is the buffet as it drops below the Mach. Crappy BC's probably also have something to do with it as well.
If you want supersonic, go CCI Velocitor or 22WMR. Velocitor is supersonic at 100 yards.
Re: Why is target ammunition subsonic?
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Unless you are telling me that .22LR's somehow circumvent physics.</div></div>
No, they don't.
All bullets just know more laws of physics than you do. It's a transition state thing. Non-linear things happen when liquids change to gases, and when objects decellerate from supersonic to subsonic, and a lot more types of changes.
<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">Unless you are telling me that .22LR's somehow circumvent physics.</div></div>
No, they don't.
All bullets just know more laws of physics than you do. It's a transition state thing. Non-linear things happen when liquids change to gases, and when objects decellerate from supersonic to subsonic, and a lot more types of changes.
Re: Why is target ammunition subsonic?
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hatidua</div><div class="ubbcode-body">The first reply covered it just fine. Then we get all the armchair physicists to weigh in on it....with essentially the same answer but more verbose. Nicely done guys
</div></div>
I don't think it did. What about precision well within the sonic transition? The original question did'nt include ranges where sonic transition would be a factor. You don't have to be physicist to contemplate and debate vs. simple dismissal.
I except Teryx's post. Yes, the bullets are more inefficient. However, are they also inherently less precise at retained supersonic speeds? Yes, they are. I'm not a physicist or expert on the bullet itself due to deformation and its exsistance in the supersonic pocket. The latter should be forgiving as proven in other animals.
The 22lr supersonic load or cartidge as a whole is generally less precise. I don't think it is a exit bore condition with velocity as previously indicated. I've spent enough time with a decent 22lr at various short ranges that I know it's not TOF or transonic issues in the difference in performance.
I put more doubt in the ass-end end of the loaded cartidge than anything in front of it.
<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: hatidua</div><div class="ubbcode-body">The first reply covered it just fine. Then we get all the armchair physicists to weigh in on it....with essentially the same answer but more verbose. Nicely done guys
I don't think it did. What about precision well within the sonic transition? The original question did'nt include ranges where sonic transition would be a factor. You don't have to be physicist to contemplate and debate vs. simple dismissal.
I except Teryx's post. Yes, the bullets are more inefficient. However, are they also inherently less precise at retained supersonic speeds? Yes, they are. I'm not a physicist or expert on the bullet itself due to deformation and its exsistance in the supersonic pocket. The latter should be forgiving as proven in other animals.
The 22lr supersonic load or cartidge as a whole is generally less precise. I don't think it is a exit bore condition with velocity as previously indicated. I've spent enough time with a decent 22lr at various short ranges that I know it's not TOF or transonic issues in the difference in performance.
I put more doubt in the ass-end end of the loaded cartidge than anything in front of it.
