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12/15/2013 5:06:54 AM EDT
I was recently shooting my 10-22 suppressed with my ss sparrow and it was in the high 40's. I was using Remington subs and CCI standard velocity. Some shots seemed ,much louder than others, and some eve sounded like they went supersonic. Does the cold increase velocity?
12/15/2013 5:57:28 AM EDT
[#1]
Cold=lower velocity
Hot=higher velocity

ETA: I think it relates more to the temp of the ammo than the ambient air temp. Example: On a cold day ammo that has been kept warm in your pocket will chrono higher than ammo that is at ambient air temp.
12/15/2013 9:31:12 AM EDT
[#2]
The threshold for sound to go from sub to supersonic depends on atmospheric conditions, I believe. Such as air temp and humidity.

I think that would have more of effect on what you're hearing than the temperature of the actual ammunition being used.
12/15/2013 11:49:53 AM EDT
[#3]
You're right. Actually we are both right. What I was talking about is some powder being temp. sensitive and the bullet going slower when cold or faster when hot.  But both ammo temp(somewhat) & air temp(mostly) play in to it.
What I meant was if you took warm ammo to the cold outside it may be more likely to go supersonic, because the threshold is lower and the ammo is going a little faster. I just may not be explaining it correctly.

From now on I should drink my morning coffee before posting. LOL
12/15/2013 12:01:17 PM EDT
[#4]


Quoted:



I was recently shooting my 10-22 suppressed with my ss sparrow and it was in the high 40's. I was using Remington subs and CCI standard velocity. Some shots seemed ,much louder than others, and some eve sounded like they went supersonic. Does the cold increase velocity?
View Quote
The cold doesn't increase the bullets velocity.

 

It does lower the speed of sound.







Thus you can go supersonic if you were very close in standard conditions.






You're right though, some powders are more temperature sensitive than others.





As I understand it, anyway.

 
12/15/2013 12:17:39 PM EDT
[#5]
I never said the cold increased the bullets velocity.
What I meant was if you took warm ammo to the cold outside it would be going a little faster than cold ammo that had been outside for a while.
What I was getting at was there could be 2 factors causing his shots to go super.
12/15/2013 12:25:43 PM EDT
[#6]
Another thing to consider is noise carries better in cold, dense air.
12/15/2013 1:00:29 PM EDT
[#7]
Quoted:
it was in the high 40's.
View Quote


Is that really considered cold in TX? Yesterday it hit 6 degrees, and that was only what I saw in the car while driving. I heard it almost reached zero.
12/15/2013 6:19:37 PM EDT
[#8]
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Quoted:


Is that really considered cold in TX? Yesterday it hit 6 degrees, and that was only what I saw in the car while driving. I heard it almost reached zero.
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Quoted:
Quoted:
it was in the high 40's.


Is that really considered cold in TX? Yesterday it hit 6 degrees, and that was only what I saw in the car while driving. I heard it almost reached zero.


I have seen negative temperatures pheasant hunting in the Texas Panhandle with a windchill of 30 below.  That's cold period.  Just remember Texas gave up land all the way into Wyoming when it became a state.  

I was shooting a .300 BLK that would not cycle subs at 50 degrees. At 60 they cycled fine.  Ambient temperature can and will cause havoc with powders, pressure and bullet velocity at cold or hot temperatures.  The colder the lower and slower or the hotter the higher the faster on pressure and velocity.
12/15/2013 8:42:57 PM EDT
[#9]
Quote History
Quoted:
You're right. Actually we are both right. What I was talking about is some powder being temp. sensitive and the bullet going slower when cold or faster when hot.  But both ammo temp(somewhat) & air temp(mostly) play in to it.
What I meant was if you took warm ammo to the cold outside it may be more likely to go supersonic, because the threshold is lower and the ammo is going a little faster. I just may not be explaining it correctly.

From now on I should drink my morning coffee before posting. LOL
View Quote


your both right.  But 6gunsal was more right.  

846 is said to be one of the powders that's sensitive to high temp.  100+

I always think altitude has more of an affect on bullet FPS.  with out knowing what the OP was shooting Some sub .22 is just faster than others is all.
12/15/2013 9:07:31 PM EDT
[#10]
Forty degrees is cold.
12/15/2013 9:10:01 PM EDT
[#11]
Quoted:
I was recently shooting my 10-22 suppressed with my ss sparrow and it was in the high 40's. I was using Remington subs and CCI standard velocity. Some shots seemed ,much louder than others, and some eve sounded like they went supersonic. Does the cold increase velocity?
View Quote


Cold temps reduces the speed of sound.  Rem Subsonics are pretty marginal on velocity.  In a bolt gun they will often go transonic.
12/16/2013 2:46:57 PM EDT
[#12]
Quote History
Quoted:
Forty degrees is cold.
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to be fair this is Texas and it was in the mid 20's at sunrise, it was also rather windy with 30 mph gusts that day. So yes, 40 is cold.
12/16/2013 2:48:13 PM EDT
[#13]
Quote History
Quoted:


your both right.  But 6gunsal was more right.  

846 is said to be one of the powders that's sensitive to high temp.  100+

I always think altitude has more of an affect on bullet FPS.  with out knowing what the OP was shooting Some sub .22 is just faster than others is all.
View Quote View All Quotes
View All Quotes
Quote History
Quoted:
Quoted:
You're right. Actually we are both right. What I was talking about is some powder being temp. sensitive and the bullet going slower when cold or faster when hot.  But both ammo temp(somewhat) & air temp(mostly) play in to it.
What I meant was if you took warm ammo to the cold outside it may be more likely to go supersonic, because the threshold is lower and the ammo is going a little faster. I just may not be explaining it correctly.

From now on I should drink my morning coffee before posting. LOL


your both right.  But 6gunsal was more right.  

846 is said to be one of the powders that's sensitive to high temp.  100+

I always think altitude has more of an affect on bullet FPS.  with out knowing what the OP was shooting Some sub .22 is just faster than others is all.
I was shooting remington subsonic, CCI standard velocity and Eley subs.
12/16/2013 6:35:58 PM EDT
[#14]
I can't call any off of the top of my head, but there are some powders that are inverse temperature sensitivity.  Meaning the colder they are the more energetic they burn.
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