Ballistics/bullet performance in cold weather

204 Ruger

Well-Known Member
Question for the more educated. Ive noticed that my rifle appears to be very quiet when the weather is below freezing(may just be imagining it). I went out a few nights back, weather was at -4C with 10mph wind and bit of snow in the air. When I fired, not only did the initial firing sound very quiet but the ballistic crack off the round was also very quiet. I was in a very open space so no surroundings to get the rapport bouncing back off but even so it seemed very very quiet.

Rifle is a 22.250 and I do have a very good sound moderator fitted, but normally its louder than on this occasion.

Is this normal/what you have experienced. I checked the empty shell, all looked ok and all powder had burned fine. Im using Hodgdon Benchmark which I believe should operate fine under much lower temps.

Could this be due to how dense the air is at these temps?

Cheers Steve
 
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Short simple answer -YES.

Now just wait for the debate to open up and the science to be explained, before long someone will raise the questions of reduced velocities (negligible at normal stalking ranges) possible sight adjustments and should I change my powder for arctic conditions. I prefer to keep all things simple myself. KISS.
 
Short simple answer -YES.

Now just wait for the debate to open up and the science to be explained, before long someone will raise the questions of reduced velocities (negligible at normal stalking ranges) possible sight adjustments and should I change my powder for arctic conditions. I prefer to keep all things simple myself. KISS.

Thanks for the reply, happy to hear the science too if thats how the thread goes. Just glad that its not just me!!I started to wonder if I had made some duff reloads. The extra padding I was also wearing seemed to take the kick out of the gun too so I was slightly bemused!!
 
I too am a strong advocate of KISS. However, not at the expense of reality.

Cold-weather-reduced velocities aren't a myth, and aren't insignificant either. In rifles of mine that normally produce muzzle velocities in the range of 2800 to 3000 f/s, the reduction I have measured is often more than 200 f/s when the temperature at firing goes from 10C down to 0C or farther. There's more, much more, to the issue than simply the "chemsitry" of powder burning. Bullets, chambers and bores all change dimensions sufficiently to reduce friction (bullet and bore), and reduce pressure (chamber) and therefore burning rate, etc.

If you REALLY want to know the truth of the matter, shoot over a chronograph, or HONESTLY shoot at paper and note the differences. I have no reason to try to get you to "believe" me, so if you shoot over a chronograph or shoot at paper and get no measurable changes - HOORAY! You have nothing to worry about. However, I live and hunt in Alaska, and I commonly hunt in temperatures that vary season-to-season from 12C to -20C, and I can assure you that in my rifles, temperature MATTERS. I have "summer" loads, and I have "winter" loads, and that's as KISS as I can keep it and still expect to 1) hit what I aim at at ranges over 100 yd, and 2) deliver the energy I expect so that the bullet will have the terminal performance I expect at all ranges.

Sometimes you can ask ballistics related questions on the internet and get answers that will keep you from wasting time and/or energy. Other times - and this is probably one of them - you just hafta 'bite the bullet' and find out for yourself. That's not a 'bad thing'...

Regards,
Paul
 
STEVIE, can more or less guarantee that what you heard was the normal reduced moderated sound/report of shot at muzzle, what you didn't hear so loud was the sonic crack because it was muffled by the snow...callie
 
Callie I forgot about the effect that snow may have on absorbing the sound simply because we haven't had any to talk of.
You're quite correct Paul you should be aware of changes in point of aim and reductions in velocity and these are best checked on the range. However at the ranges that most of us shoot and with a relatively narrow temperature variation in this country normally, it's not usual to need different summer and winter ammo. Now Alaska is an entirely different situation.
 
Hmmm with the temps here in the UK as low as they are now I wonder if there will be a much greater difference than we are used to. Have just checked outside and here it's -10 degrees C and we are milder here out on the east than most it seems. Now bear in mind that Roe Buck stalking will often be done with the temps reaching 16-20 dgrees C and that is quite a range and enough to effect velocity without factoring in the effect of the denser cold air.
 
I too am a strong advocate of KISS. However, not at the expense of reality.

Cold-weather-reduced velocities aren't a myth, and aren't insignificant either. In rifles of mine that normally produce muzzle velocities in the range of 2800 to 3000 f/s, the reduction I have measured is often more than 200 f/s when the temperature at firing goes from 10C down to 0C or farther. There's more, much more, to the issue than simply the "chemsitry" of powder burning. Bullets, chambers and bores all change dimensions sufficiently to reduce friction (bullet and bore), and reduce pressure (chamber) and therefore burning rate, etc.

If you REALLY want to know the truth of the matter, shoot over a chronograph, or HONESTLY shoot at paper and note the differences. I have no reason to try to get you to "believe" me, so if you shoot over a chronograph or shoot at paper and get no measurable changes - HOORAY! You have nothing to worry about. However, I live and hunt in Alaska, and I commonly hunt in temperatures that vary season-to-season from 12C to -20C, and I can assure you that in my rifles, temperature MATTERS. I have "summer" loads, and I have "winter" loads, and that's as KISS as I can keep it and still expect to 1) hit what I aim at at ranges over 100 yd, and 2) deliver the energy I expect so that the bullet will have the terminal performance I expect at all ranges.

Sometimes you can ask ballistics related questions on the internet and get answers that will keep you from wasting time and/or energy. Other times - and this is probably one of them - you just hafta 'bite the bullet' and find out for yourself. That's not a 'bad thing'...

Regards,
Paul


Thanks Paul, I agree with everything you have said(and who better to comment on the impact of cold weather than you!!!) and as soon as I get chance Ill be out shooting paper in the lowest temp I can just to be sure about the POI. It makes sense that velocity will be impacted I just want to be confident about how much difference it will make to my shots within 150 yards(Which is typically the range where most of my shots on fox are).
 
STEVIE, can more or less guarantee that what you heard was the normal reduced moderated sound/report of shot at muzzle, what you didn't hear so loud was the sonic crack because it was muffled by the snow...callie


When I first put the mod on the rifle back in April I couldn’t believe the difference it made and was surprised that I could even hear the click of the bolt. This just seemed weird because your right its the crack of the bullet that i didn’t hear, it even seemed like the round had jammed in the barrel :). I just need to shoot some paper and be sure about what is actually happening. I think this weather is around for a while and I would want to miss a fox at longer ranges due to this.
 
Some powders are temperature sensitive and behave differently at different temperatures.

Hodgsons extreme powders are a lot less temperature sensitive.

Varget is supposed to be one of the least temperature sensitive which is one of the reasons I have switched from H414 to Varget.

See the quote from their website below.

The first of Hodgdon's revolutionary Extreme Extruded Powders, VARGET features small extruded grains for uniform metering, insensitivity to hot/cold temperatures and higher energy for improved velocities over other powders in its burning speed class. Easy ignition and clean burning characterize other features that translate into superb accuracy, higher scores and more clean, one shot kills. The perfect powder for competitive Match shooting 223 Remington and Heavy bullets. Outstanding performance and velocity can be obtained in such popular cartridges as the 223 Remington, 22-250 Remington, 308 Winchester, 30-06, 375 H&H and many more. Available in 1 lb. & 8 lb. containers.
 
Some powders are temperature sensitive and behave differently at different temperatures.

Hodgsons extreme powders are a lot less temperature sensitive.

Varget is supposed to be one of the least temperature sensitive which is one of the reasons I have switched from H414 to Varget.

See the quote from their website below.

The first of Hodgdon's revolutionary Extreme Extruded Powders, VARGET features small extruded grains for uniform metering, insensitivity to hot/cold temperatures and higher energy for improved velocities over other powders in its burning speed class. Easy ignition and clean burning characterize other features that translate into superb accuracy, higher scores and more clean, one shot kills. The perfect powder for competitive Match shooting 223 Remington and Heavy bullets. Outstanding performance and velocity can be obtained in such popular cartridges as the 223 Remington, 22-250 Remington, 308 Winchester, 30-06, 375 H&H and many more. Available in 1 lb. & 8 lb. containers.

Thats what i read, Im using Benchmark so should be fine at -4c....However, I still felt the need to see if it had burned ok!!! Seriously it seemed as quiet as a 22LR with sub sonic rounds!!
 
STEVIE:- It's not a bad idea to check on paper if nothing else it puts your mind to rest and takes "That what if factor?" out of the equation, as robbobsam says with the hodgdons extreme powders there shouldn't be any real difference, maybe 1/10" out to 200 yds with your 22-250, but as you say "checking" is better than "thinking", my own powder preference for the 223 is H 322. ATB....callie
 
You all are correct about the 'normal' differences between season-to-season variations in the UK and in AK. The matter of sound absorption by snow both falling and on the ground is also very real, and I suspect maybe even more noticeable when using a moderator (I wish I could find out about that first-hand :().

I also read about the "insensitivity" of Hodgdon's "extreme" powders. However, when I actually tested a couple of them, I found no measurable difference between the "new" powders and the "old" ones in terms of temperature "sensitivity" as the temperatures fall. I'm not averse to calling 'a spade a spade' but I hesitate to do that until I know the truth for a fact, and know that someone knowingly lied. I'm not sure Hodgdon lied about the lack of temperature sensitivity of their new powders for two reasons:

1) Most of the temperature issues in the US and Africa are "hot" ones, not cold ones. (More about that in a moment.)
2) The powder ALONE may be relatively "insensitive" to temperature (More about that too.)

With regard to "1" the complaints of most shooters/reloaders/hunters in the US are related to shooting Prairie Dogs in the summer, and going to Africa and experiencing really hot temperatures relative to where they came from in the States. I suspect (but don't know) that Hodgdon focused on changes in their powders that dealt more with increases in ambient temperature than decreases in it. One might expect the chemistry of powder burning to be uniform with temperature as the temperature goes up or down. However, not knowing what method(s) Hodgdon's used for achieving their reported insensitivity we can't know if it is some process that may mitigate variation as temperature rises from "normal" temperate zone values as opposed to having a linear response across temperature. (Meaning it responds the same regardless of the direction of change.)

With regard to "2", I'm not sure that the effect of a 20C change in temperature is the same on the system that a rifle is as temperature goes up and down. For example, let's suppose that there is some point at which a movement in metal results in some 'threshold' or 'cascade' effect. Up to that threshold, the effect is unmeasurable. Beyond that point the effect is significant. I can imagine that as long as the bullet is sealing the bore, the effect is marginal, but once the barrel and bullet differ sufficiently to allow gas to blow by the bullet, the effect is substantial. I'm not saying this IS what is happening, I'm simply offering an easy-to-explain example for why going one direction in temperature change might be different than going the other.

I don't KNOW what the reason is that the new, supposedly temperature insensitive Hodgdon powders I have tested haven't been "insensitive" to falling temperatures, but I know that they haven't. When I shoot all the various powders I have at temperatures below 0C, "things change" at the target butts and across the chronograph. In fact, the only "dud" I have actually experienced in over 42 years of reloading was at the range on a 0C day using the very large case of the .50 Alaskan and "only" a large rifle primer. The 'cure' was simply to go to a "magnum" primer. Now THAT is PURELY a "chemistry" matter, but it was also PURELY a function of temperature as well.

I'll close by repeating that the BEST way to get THE answer is to 'pull the trigger' and measure the changes if any. AND, that is a "good thing". It means finding out something about your rifle FIRST HAND, and not having to wonder if your particular rifle isn't "just a little different" than someone else's rifle that told you to expect "this" response.

Paul
 
Question for the more educated. Ive noticed that my rifle appears to be very quiet when the weather is below freezing(may just be imagining it). I went out a few nights back, weather was at -4C with 10mph wind and bit of snow in the air. When I fired, not only did the initial firing sound very quiet but the ballistic crack off the round was also very quiet. I was in a very open space so no surroundings to get the rapport bouncing back off but even so it seemed very very quiet.

Rifle is a 22.250 and I do have a very good sound moderator fitted, but normally its louder than on this occasion.

Is this normal/what you have experienced. I checked the empty shell, all looked ok and all powder had burned fine. Im using Hodgdon Benchmark which I believe should operate fine under much lower temps.

Could this be due to how dense the air is at these temps?

Cheers Steve

Crickey - I thought I needed my ears cleaning our on Saturday morning. I shoot a .270 (quel surprise) and I could barely hear a crack when I fired off a couple of rounds. Very strange indeed.

Interested to know the reason for why!

DC
 
Crickey - I thought I needed my ears cleaning our on Saturday morning. I shoot a .270 (quel surprise) and I could barely hear a crack when I fired off a couple of rounds. Very strange indeed.

Interested to know the reason for why!

DC

I too thought I was going mad. The funny thing is I was showing a mate how much quieter the rifle is with the mod on. he has a 243 and is thinking of having one fitted but had never heard one without 'he was like *&^&%&^$%^$% I cant believe how quiet it is'.....:) So glad its not just me, I thought Id made some bum loads at first.
 
why cant you use a moderator on your rifles?
It's crazy stupid in the US, but basically if you want a moderator, you're assumed to be a poacher or an assassin. Technically it is possible to own a moderator in the US, but it requires the same hoops to be jumped through as it would if you wanted to own a fully automatic machine gun, or a license to make explosives. First you have to pay for the "Stamp" from the Bureau of Alcohol, Tobacco, Firearms and Explosives. Last I heard it was $300. (I heard it was $600 now, but can't confirm that.) THEN you have to go ask permission to have one from the local Chief of Police. (That's where the "What do you want that for? Are you planning on assassinating someone?" questions start.) Then you have to get an FBI back-ground check. Then, because they are such a "controlled substance" here, the cost of a truly mediocre one starts at ~$800 and goes up fast. Also, because they are considered "destructive devices" under the National Firearms Act (NFA), they HAVE to have a serial number. The "Stamp" you buy is for ONE serial number. If that moderator is damaged, or you want to get another one, you have to get a new stamp AND you have to prove the first one was destroyed or returned to the manufacturer.

Considering the hoops you guys have to jump through to get your licenses - and you have my genuine and deepest sympathies - I assume you are not taken aback by the above. But for most of us that haven't grown up with such draconian government control, it's a pretty big pill to swallow. I want a moderator so bad that I have been tempted to take that pill, but so far not. I have found a way 'around' the interrogation by the local Chief of Police and the FBI background check (my company would get the Stamp and license, not me personally), but still, I REALLY, REALLY, don't like the government knowing any more about me that I absolutely have to.

I have a Type 03 Federal Firearms License (FFL) that allows me to collect "Curios and Relics" as long as I do no conduct a business of buying and selling firearms. I had to get the local cop's "permission", and I had to agree to let them review my records if given 'reasonable' notice. The reason I don't get a Type 01 FFL which would allow me to buy and sell essentially any firearms that weren't fully automatic, is that to do so I would have to agree that they could come to the address of the FFL at ANY time of day, WITHOUT NOTICE, and search WITHOUT WARRANT, not only the premises but also ANY BUILDING ATTACHED to the premises. I simply can't bring myself to allow federal agents free reign to search my property in the middle of the night without cause or warrant. Of course they do this only rarely, but nonetheless, they DO IT. And they DO IT when you **** them off, and I seem to have a knack for ****ing off authorities.

Sorry to be off-topic, but I wanted to give a thorough answer.

Regards,
Paul
 
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It's crazy stupid in the US, but basically if you want a moderator, you're assumed to be a poacher or an assassin. Technically it is possible to own a moderator in the US, but it requires the same hoops to be jumped through as it would if you wanted to own a fully automatic machine gun, or a license to make explosives. First you have to pay for the "Stamp" from the Bureau of Alcohol, Tobacco, Firearms and Explosives. Last I heard it was $300. (I heard it was $600 now, but can't confirm that.) THEN you have to go ask permission to have one from the local Chief of Police. (That's where the "What do you want that for? Are you planning on assassinating someone?" questions start.) Then you have to get an FBI back-ground check. Then, because they are such a "controlled substance" here, the cost of a truly mediocre one starts at ~$800 and goes up fast. Also, because they are considered "destructive devices" under the National Firearms Act (NFA), they HAVE to have a serial number. The "Stamp" you buy is for ONE serial number. If that moderator is damaged, or you want to get another one, you have to get a new stamp AND you have to prove the first one was destroyed or returned to the manufacturer.

Considering the hoops you guys have to jump through to get your licenses - and you have my genuine and deepest sympathies - I assume you are not taken aback by the above. But for most of us that haven't grown up with such draconian government control, it's a pretty big pill to swallow. I want a moderator so bad that I have been tempted to take that pill, but so far not. I have found a way 'around' the interrogation by the local Chief of Police and the FBI background check (my company would get the Stamp and license, not me personally), but still, I REALLY, REALLY, don't like the government knowing any more about me that I absolutely have to.

I have a Type 03 Federal Firearms License (FFL) that allows me to collect "Curios and Relics" as long as I do no conduct a business of buying and selling firearms. I had to get the local cop's "permission", and I had to agree to let them review my records if given 'reasonable' notice. The reason I don't get a Type 01 FFL which would allow me to buy and sell essentially any firearms that weren't fully automatic, is that to do so I would have to agree that they could come to the address of the FFL at ANY time of day, WITHOUT NOTICE, and search WITHOUT WARRANT, not only the premises but also ANY BUILDING ATTACHED to the premises. I simply can't bring myself to allow federal agents free reign to search my property in the middle of the night without cause or warrant. Of course they do this only rarely, but nonetheless, they DO IT. And they DO IT when you **** them off, and I seem to have a knack for ****ing off authorities.

Sorry to be off-topic, but I wanted to give a thorough answer.

Regards,
Paul

WOW, and I thought getting an FAC over in the UK was a challenge sometimes!!!
 
Another thing to remember folks regardless of powders even "extreme" powders info given is between 0---150F, 32F is freezing point 0c so in Centigrade we're talking -18 --0-- +65C,

Now as we all know most metals shrink the colder it gets and, the more brittle it becomes, and no your rifle's not going to shatter in your face, before that happens, depending on the steel alloy your rifle's made of and other components it would sieze up and the first thing to break would most likely be the firing pin spring so you're safe to below -40 C and if you're out hunting in those sort of temps you want shooting, I doubt even Hodgdons powders would ignite at those low temps.

So it's -10 -15C outside and the diameter of the barrel's shrunk x amount of tens of 1 thousand of an inch/microns, no big deal, the lead being softer than steel (and a very thin coat of copper). The lead, because it's so much denser than steel shrinks less so therefore the bullet creates greater friction and you have a greater drop of Muzzle Energy, less fps, less distance and greater bullet drop in VERY cold weather...simples ....callie.
 
I like the theory Callie, but surely if the bullet were to shrink less than the barrel the fit would then be tighter resulting in higher internal pressure which normally relates to higher velocities?
 
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