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Discussion Starter · #1 ·
It seems terribly popular that a lot of target ammo is sub-sonic. Aguila, Federal, CCI, etc. all have such an ammo in their line-up. Why? Does the lower velocity make for better accuracy? Stupid question, maybe I should know better. Thanks.

steve
 

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Almost all target .22 rimfire ammo is subsonic. There are a couple of reasons for this. First, subsonic ammo is less wind sensitive. Without getting too technical, wind effects on bullets are strongly correlated to the loss in velocity (as a proportion of total velocity) between the muzzle and the target. Subsonic .22 rimfire bullets shed velocity more slowly than supersonic bullets. Secondly, bullets that pass through the trans-sonic zone (go from supersonic to subsonic) can become unstable. At typical rimfire ranges, most supersonic .22 ammo will pass through this zone, harming accuracy. Hope this helps.
 

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Discussion Starter · #3 ·
[smoke rolling out of ears due to over-load] Thanks! The part about making the transition from super to sub-sonic is new to me. Its all real interesting. Gotta digest all that. [smoke *still* rolling out of ears]

steve
 

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The old NASA test pilots found out exactly how turbulent that sub to super sonic transition can be. Bout rattled them old planes apart. Bullets are the same.

If it's easier to picture, think of it this way..The supersonic shock wave does not go away all at once. The down wind side will collapse first, leaving a shock wave pressure wall that the bullet "bounces" off of. This throws the shot even farther to the downwind side.

As a rule target shooters want to stay out of the trans sonic speed range. Centerfire shooters try to stay above it. And since that's not an option for rimfires, we try to stay below it.

The transonic speed range extends from around 1000fps all the way up to around 12-1400fps.

http://www.guns.connect.fi/rs/bulnoise.html
 

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Discussion Starter · #7 ·
The accuracy issue and noise levels are all great points, thanks for the input.

But dies it still retain enough energy at 100 yards to flatten a groundhog? This is my prime concern. Tack driving is cool, but can it do the job?

Please excuse the ignorance, I was brought up under the "need for speed" thinking, especially in rimfires.

Keep the replies coming... this very educational. steve
 

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I do a lot of shooting at 100 yards.

The difference in accuracy at that range between subsonic and HV ammo is not enough to cause anyone to miss any type of small game much less something the size of a groundhog.

For varmits the HV ammo is still the best bet. The subsonic does not hit very hard at 100 yards.

The subsonic is thought to be better in the wind than HV by a lot of people that know much more about those things than I do.

That has not been my experience on the 100 yard line of the dewar.

They are most likely right but you can't prove it by me.
 

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Steve, I love shooting rimfires, but I'm the first to admit that a .22lr is a pip-squeek round. I don't think the difference in hitting power between a subsonic and HV round would make much difference on a groundhog at 100 yards, or any other range for that matter. What will make a difference is shot placement, so go with the most accurate round for your equipment, and make head shots. Result will be a dead whistle pig.
 

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I ran my own bullet test on sub and supersonic .22 ammo, and there was a definite difference. The hot rounds were all over the place, while the low end subsonic (Aguila, CCI Std Vel) was definitely better. I was getting 3/4" patterns at 50 yards with subsonic, while CCI Stinger was more like 1.5" to 2" at the same range.

Surprised me when I got a brick of Federal UM1 and found that it was supersonic. Some of the best stuff I've ever fired, too.
 

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JohnO,
It is not surprising that you found the UM1 to be good stuff. It was initially designed for the US shooters for the '92 Olympics. Unfortunately, it and all of it's brothers (UM1B, 900, and 900B) are no longer being made, so enjoy what you have.

Al
 

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hogs

steve, i think hogs are a bit tough to be after at 100 yards with a .22 lr. If i were going to do it though, i would find the most accurate HYPER velocity round that will shoot in your gun, and use that. I know under hunting conditions i dont use the equipment to guarantee a shot through the eye to use a subsonic round (no bench rest, no target scope), and i dont think they have enough juice to do the job on a 15 lb hog. I would start with stingers, velocitors, aguila hv hp, then quick shok. If they wont group decent at all then maybe minimags or eley hv hp. For that range a magnum or a .17 is preferred. Magnums dont even "poof" a hog even though they do work adequately.
 

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steve-in-kville,
But does it still retain enough energy at 100 yards to flatten a groundhog? This is my prime concern. Tack driving is cool, but can it do the job?
Take a look at some typical ballistics: (Remington)

.22LR 40 Gr. Standard Velocity 'Target'
MV = 1150, ME = 117 / 50 Y V = 1048, 50 Y E. = 98 / 100 Y V = 976, 100 Y E = 85

.22LR 40 Gr. High Velocity
MV = 1255, ME = 140 / 50 Y V = 1113, 50 Y E. = 110 / 100 Y V = 1017, 100 Y E = 92

.22LR 33 Gr. HP Hyper Velocity
MV = 1500, ME = 165 / 50 Y V = 1247, 50 Y E. = 114 / 100 Y V = 1075, 100 Y E = 85

As you can readily see, all have pretty much 'pooped-out' at 100 yards, energy wise...! ! :(

As others have already indicated, the .22LR is not a 100 yard chuck cartridge...! ! :eek:

You should be considering the .22 WMR or the .17 HMR...! ! ;)
 
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