Cold weather ammo testing.

[Gleedus]

We often hear that cold weather and 22lr ammo dont mix. Ive been testing a variety of ammo this winter. I'm using a RimX with a IbI barrel at 26" 1-16 twist.
I used SK Long Range, Rifle Match (3 lots), Pistol Match, Center X, Eley Force, Contact (2 lots), Match, Tenex Biathlon, Federal Target, CCI sv. And several others.

Testing is 50 yards 10 shot groups 210 yards 20 shot groups. At 200 I only measure the vertical. Most ammo I have multiple groups

The first 1000 rounds I could track improvement in accuracy. I'm now at 26-2700

We typical have 950 hpa to 978 hpa. I got this rifle over Christmas 2020 so I have no warm weather data yet.

I can see no difference in average accuracy from 0⁰c/2⁰f to -10⁰c/14⁰ f at -15⁰c / 5⁰f I see some degraded accuracy across all ammo. The Tenex Biathlon in my rifle was alway one of the worst regardless of temp.

The SD of velocity is progressively worse with colder temps but doesnt show on target at long range.

Lapua/ SK ammo is the most temp sensitive in my tests. But seems to maintain accuracy the coldest. Also the SD stay very consistent.

Eley is surprisingly temp stable and hold accuracy very well to -10⁰c/14⁰f at the colder temps the groups were slightly less consistent. Eley Force and contact are my best two ammo for accuracy.

Federal below -8⁰c/19⁰f starts to loose stability by -15⁰c/5⁰f its key holes at 50 and wont stay on a 8x11 paper. I shot some Target high velocity (same bullet) and it improved slightly to 3-4" groups plus odd fliers.

CCI sv is very temp stable under most conditions. The accuracy remained the same till -10⁰c/14⁰f but at -15⁰c/5⁰f the groups grew considerably and I have very slight key holing on the occasional round.

My limited testing shows accuracy holding up better then I expected with cold weather and if you are accurately tracking velocity change I see no reason to keep ammo warm until shooting your stage. 22lr ammo cools very fast so if you start with warm ammo your velocities will change well shooting the stage.

What results have you guys gotten with cold weather?

 

[straightshooter1]

We often hear that cold weather and 22lr ammo dont mix. Ive been testing a variety of ammo this winter. I'm using a RimX with a IbI barrel at 26" 1-16 twist.
I used SK Long Range, Rifle Match (3 lots), Pistol Match, Center X, Eley Force, Contact (2 lots), Match, Tenex Biathlon, Federal Target, CCI sv. And several others.

Testing is 50 yards 10 shot groups 210 yards 20 shot groups. At 200 I only measure the vertical. Most ammo I have multiple groups

The first 1000 rounds I could track improvement in accuracy. I'm now at 26-2700

We typical have 950 hpa to 978 hpa. I got this rifle over Christmas 2020 so I have no warm weather data yet.

I can see no difference in average accuracy from 0⁰c/2⁰f to -10⁰c/14⁰ f at -15⁰c / 5⁰f I see some degraded accuracy across all ammo. The Tenex Biathlon in my rifle was alway one of the worst regardless of temp.

The SD of velocity is progressively worse with colder temps but doesnt show on target at long range.

Lapua/ SK ammo is the most temp sensitive in my tests. But seems to maintain accuracy the coldest. Also the SD stay very consistent.

Eley is surprisingly temp stable and hold accuracy very well to -10⁰c/14⁰f at the colder temps the groups were slightly less consistent. Eley Force and contact are my best two ammo for accuracy.

Federal below -8⁰c/19⁰f starts to loose stability by -15⁰c/5⁰f its key holes at 50 and wont stay on a 8x11 paper. I shot some Target high velocity (same bullet) and it improved slightly to 3-4" groups plus odd fliers.

CCI sv is very temp stable under most conditions. The accuracy remained the same till -10⁰c/14⁰f but at -15⁰c/5⁰f the groups grew considerably and I have very slight key holing on the occasional round.

My limited testing shows accuracy holding up better then I expected with cold weather and if you are accurately tracking velocity change I see no reason to keep ammo warm until shooting your stage. 22lr ammo cools very fast so if you start with warm ammo your velocities will change well shooting the stage.

What results have you guys gotten with cold weather?

I ran a small "cold weather" test, but not in extreme cold's, to see what kind of difference I might see. I tested CCI SV's, Center-X and Federal Ultra Match. The SV's performance and chono results improved with the cooler temperature. There was no changes with the Center-X and the Federal Ultra Match did worse at the cooler temperature.

The understanding that I took away from this little test was simply that various cartridge design (mainly the powder and lubricants used) is affected differently by temperature one way or another. So, the only way to know how a particular ammo performs in a particular barrel, one needs to test and take notes so that one is able to calculate firing solutions in the environment one is going to be shooting in.

 

[Kisssofdeath]

I haven't shot yet in weather that cold. My lowest IIRC is around 40° and I saw no significant difference in group size from when the temps were in the high 90's here in SC.

I would also note that I haven't shot a good box/Lot of Tenex in 2-3 years. Shot regular and Pistol type.

 

[Gleedus]

At 5⁰f I was grouping 0.75 ave for 10 shots st 50 with everything except CCI sv and the federal. Tenex biathlon was 1". Somewhere below 12-14⁰f i find my personal accuracy starts to suffer if I'm out long. Especially with wind and I always have wind...
I find that with lapua- Sk you need to have detailed velocity curves charted. The linear 1 fps per degree doesnt work. I dont know were the curves all change but i'm seeing 4 fps per ⁰c below freezing. Last summer it was 1 fps with my other rifle.

I have not had colder then -15⁰c/5⁰f on a weekend this winter yet to test in.

I find Eley Tenex and Match to shoot very consistent at 200. No fliers but larger groups then contact.
My rifle doesnt like center x anybetter. Some RM lots are good.

Below half the field you mean half of possible points? Thats rough...

 

[JimTN]

Did anyone notice whether the lube on your ammo "glazed over" to look similar to donut glaze?? I shot some various ammo a year or two ago in high 30's to low 40's, and noticed the lube solidified to some extent to resemble the donut glaze. Haven't shot RF in temps that cold since. LOL

 

[Gleedus]

Depending on ammo. Sk still is oily even at 5⁰f it is just getting tacky. You also get more lube smear on the target then when warm.
Other wax type ammo can look glassy depending on the bullet color/ finish.
Biathlon has less lube and drier then standard ammo. I wonder if its more to do with reliability then accuracy? (I only have had eley biathlon lapua might be different.)

 

[barronian]

I started blaming my ammo for my poor cold weather groups, and my initial testing appeared to support blaming the ammo...

However i later found out that the temperature of my gun had more to say than the temp of the ammo (yea i know they are usually related but i was curious ...)

so i shot 50 to 250 rounds (Eley Match) at various temperatures between -10C and 24C. at each temp i collected four sets of data
- one with cold gun and frozen ammo (under 5C the ammo temp matched the gun temp)
- one with cold gun and 22C ammo
- one with warm gun (c. 22C ) and frozen ammo
- one with warm gun (c. 22C ) and 22C ammo.

the conclusions so far with my setup are that
- a 35C change in ammo temp produces about a 2ft/sec velocity change.
- a 35C change in gun temp produces about a 18ft/sec velocity change.
- the ES /SD doesnt change very much with drop in temp (less than i expected) but there is a considerable rise in ES/SD around 5C to -3C.

still a work in progress.

 

[Gleedus]

I just seen now you had a cold weather post this year! I thought I kept up in the rimfire section!

The cold rifle thing I have seen in centerfire as well. I no longer just heat or cool ammo for testing as it is not accurate. Rifle and ammo same temp. This is one of the reasons I do not want to have ammo in my pocket and a cold rifle as I have no idea what velocity I will have for sure.

Eley your results are simular to mine. With the cold gun included. I found a drop off around freezing or slightly above with most ammo. (The other rifle)
SD very slight change below freezing for Eley could be debated.
SK no proven change down to -15⁰c

I dont completely subscribe to the cold barrel = colder lube "theory". It has relevance for sure but with long continued strings of fire I can not get the velocity to change. Perhaps what little heat is created is gone to fast? But I do get mirage off the barrel after a few mags so there is some heat there.

They why is of less interest to me then the results.
At what point does ammo degrade to the point I need a winter ammo for matches. If I do ammo testing now will it be totally different in the summer? This is for PRS not BR so different criteria to a point.

Accurate velocity tracking and I can get the results I need.

Do I have different / worse results then guys with shorter barrels?

 

[ma smith]

maybe test some lapua polar whatever
since your rifle hates eley version

 

[Gleedus]

test some lapua polar whatever since your rifle hates eley version

Considered it but my rifle doesnt like the Cx. long lots of sk rifle match are ok but my center x is short and doesnt shoot. Eley tenex is short and doesnt shoot. The tenex biathlon is worse then standard tenex.

I'll have to try the polar and cx in a rifle that likes lapua.

From what I see I need -15⁰c to be worth considering polar.

 

[Bloody_Tailgate]

After hearing the results of the NRL22 match in Marshall last weekend I had to figure out what happened. There were several very good shooters who performed uncharacteristically bad. Last night a tried my own temperature test and here's what I found.

Lapua Center X
Bergara B14R
Magnetospeed

Rifle and ammo were the same temperature for all tests.

Temp (F) MV Avg (fps)
72 1082
31 1052
-5 1032

I also looked up the speed of sound based on temperature and found the following:

Temp (F) Speed of Sound (fps)
+20 1073
+10 1062
0 1050
-5 1045
-10 1040
-20 1027

As you can see, at -5 degrees my average was borderline supersonic, probably in the transonic zone. The highest velocity for the -5 shot string was 1047 which appears as though it would have left the muzzle supersonic, and immediately started the turbulent transition. As the temp drops and the speed of sound drops, there is a good chance many of the shooters were seeing the effects of transitioning from supersonic to subsonic which could explain at least a portion of the issues. Keep in mind, the wind chill during the match was approximately -25.

 

[Gleedus]

After hearing the results of the NRL22X match in Marshall last weekend I had to figure out what happened. There were several very good shooters who performed uncharacteristically bad. Last night a tried my own temperature test and here's what I found.

Lapua Center X
Bergara B14R
Magnetospeed

Rifle and ammo were the same temperature for all tests.

Temp (F) MV Avg (fps)
72 1082
31 1052
-5 1032

I also looked up the speed of sound based on temperature and found the following:

Temp (F) Speed of Sound (fps)
+20 1073
+10 1062
0 1050
-5 1045
-10 1040
-20 1027

As you can see, at -5 degrees I was borderline supersonic, probably in the transonic zone. As the temp drops and the speed of sound drops, there is a good chance many of the shooters were seeing the effects of transitioning from supersonic to subsonic which could explain at least a portion of the issues. Keep in mind, the wind chill during the match was approximately -25.

Interesting.... I dont buy the transonic transition in summer. I have supersonic ammo that is better at 200 yd then the subsonic version. At 50 yds they shoot the same.
BUT!!!
Lets add in.
Colder weather less velocity. = less rpm = less stability.
Cold air more dense = more rpm required for stability = less stability

A naturally unstable bullet that may put over the edge... at -5⁰f your colder then I have tested yet. The wind chill doesn't matter for the math in my understanding.

So would a 1-12 twist be better? Or the 1-9 seems like a lot of spin drift.

The federal target sv wont stay on a 8x11 paper at 50 and the HV version will so that makes me believe faster twist is good.

Oh what barrel do you have? Brand length twist...

 

[Bloody_Tailgate]

Interesting.... I dont buy the transonic transition in summer. I have supersonic ammo that is better at 200 yd then the subsonic version. At 50 yds they shoot the same.
BUT!!!
Lets add in.
Colder weather less velocity. = less rpm = less stability.
Cold air more dense = more rpm required for stability = less stability

A naturally unstable bullet that may put over the edge... at -5⁰f your colder then I have tested yet. The wind chill doesn't matter for the math in my understanding.

So would a 1-12 twist be better? Or the 1-9 seems like a lot of spin drift.

The federal target sv wont stay on a 8x11 paper at 50 and the HV version will so that makes me believe faster twist is good.

Oh what barrel do you have? Brand length twist...

Bergara rifle. 18" barrel 1-16 twist.

I'm not arguing with your results, but it's pretty hard to discredit guys like Bryan Litz because you have ammo that shoots consistent at 200 yards. Plus, I've seen first-hand examples, one where a squad mate was shooting a 308 at a match and doing fairly well. One stage was 1200 and his rifle/load completely fell apart. I was spotting for him and one round would hit 40' in front of the target, then the next would be 5' off to the right. The temp that day was 90 degrees plus.

 

[Gleedus]

Bergara rifle. 18" barrel 1-16 twist.

I'm not arguing with your results, but it's pretty hard to discredit guys like Bryan Litz because you have ammo that shoots consistent at 200 yards. Plus, I've seen first-hand examples, one where a squad mate was shooting a 308 at a match and doing fairly well. One stage was 1200 and his rifle/load completely fell apart. I was spotting for him and one round would hit 40' in front of the target, then the next would be 5' off to the right. The temp that day was 90 degrees plus.

Ya I'm not interested in arguing with Brian lol! Different bullets are better at the transition with centerfire as well. It may also depend on how stable the bullet is in supersonic flight before the transition? I dont know all I have is my test results focused on rimfire. And I like the info and results of others tests. You brought up the speed of sound I never thought of that I like that. It would make sense that it plays a part.

I have a 26" and at 32⁰f I'm 1021 fps with a lot number that starts with 27. So 1073 fps in their test rifles.
From 32⁰f to 5⁰f I'm losing 33 fps. So it looks like I lose velocity faster then you. Interesting...

 

[Bloody_Tailgate]

Ya I'm not interested in arguing with Brian lol! Different bullets are better at the transition with centerfire as well. It may also depend on how stable the bullet is in supersonic flight before the transition? I dont know all I have is my test results focused on rimfire. And I like the info and results of others tests. You brought up the speed of sound I never thought of that I like that. It would make sense that it plays a part.

I have a 26" and at 32⁰f I'm 1021 fps with a lot number that starts with 27. So 1073 fps in their test rifles.
From 32⁰f to 5⁰f I'm losing 33 fps. So it looks like I lose velocity faster then you. Interesting...

You're shooting a considerably longer barrel, I wonder if that has anything to do with it? The guys at Vudoo did velocity testing from 26" down to 16" barrels. I can't remember the exact numbers but they essentially started with a 26" barrel and cut it down, re-crowned and tested over and over. I believe they found that over 22" the velocities were slower, then from 22" to 18" they were consistent. You may actually be slowing down in the barrel, thus causing a higher rate of loss in colder temps? It would stand to reason that if the barrel is slowing the bullet, and the bullet starts off slower, it would slow down at a faster rate.

 

[Gleedus]

You're shooting a considerably longer barrel, I wonder if that has anything to do with it? The guys at Vudoo did velocity testing from 26" down to 16" barrels. I can't remember the exact numbers but they essentially started with a 26" barrel and cut it down, re-crowned and tested over and over. I believe they found that over 22" the velocities were slower, then from 22" to 18" they were consistent. You may actually be slowing down in the barrel, thus causing a higher rate of loss in colder temps? It would stand to reason that if the barrel is slowing the bullet, and the bullet starts off slower, it would slow down at a faster rate.

Yup they did. Lapua doesnt like long barrels as far as velocity is concerned. Eley holds velocity better.
I find it interesting that cold affects me more too.
I dont care about velocity. To fast you get more wind drift. I am hoping for smaller SD. Maybe maybe not...

 

[grauhanen]

CRPS Shooter, in your first post in this thread about cold temperature ammo testing, you say you shoot 10-shot groups at 50 and 20-shot groups at 210 yards. When you evaluate the MV and SD of different ammos, how many shots in the strings? What chronograph are you using?

 

[straightshooter1]

It was ~2 1/2 ago when I did my little test (as I said above, not in extreme cold) to see how much a large temperature variance might make. Here it is:

Tested: ER Shaw Ruger Precision Rimfire Barrel

Just put on a new ER Shaw barrel for the RPR... Night and day difference over factory barrel. Have about 400 rounds through it today both breaking in and group testing. Factory barrel shot okay (.6-1" 5 and 10 shot groups and depending on ammo) this is Ruger Factory Barrel after bedding...

www.snipershide.com

Tested: ER Shaw Ruger Precision Rimfire Barrel

Just put on a new ER Shaw barrel for the RPR... Night and day difference over factory barrel. Have about 400 rounds through it today both breaking in and group testing. Factory barrel shot okay (.6-1" 5 and 10 shot groups and depending on ammo) this is Ruger Factory Barrel after bedding...

www.snipershide.com

 

[Gleedus]

CRPS Shooter, in your first post in this thread about cold temperature ammo testing, you say you shoot 10-shot groups at 50 and 20-shot groups at 210 yards. When you evaluate the MV and SD of different ammos, how many shots in the strings? What chronograph are you using

Magneto

30 minimum I record the 10 at 50 and the 20 at 200. If I really want to check out a ammo I'll do 3 groups at 200 so then I have 60.

I also will/ have done multiple days of same temp to see if I get repeatable results. I do.
All of my temp tests are done rifle and ammo same temp.

my opinion.... 30 rounds I see as a minimum for average speed. SD 50 rounds will have it. ES all of them... lol 50 gives a good idea. Typically batch to batch of 30-50 ES is simular. I dont look at ES much unless I get a a extra large ES in a group at distance.
I've done several hundred of one to see what minimum shows close to average without wasting ammo. Bulk ammo takes more.

More then you asked for I realize. I like details i guess.

 

[Gleedus]

It was ~2 1/2 ago when I did my little test (as I said above, not in extreme cold) to see how much a large temperature variance might make. Here it is:

Tested: ER Shaw Ruger Precision Rimfire Barrel

Just put on a new ER Shaw barrel for the RPR... Night and day difference over factory barrel. Have about 400 rounds through it today both breaking in and group testing. Factory barrel shot okay (.6-1" 5 and 10 shot groups and depending on ammo) this is Ruger Factory Barrel after bedding...

www.snipershide.com

Tested: ER Shaw Ruger Precision Rimfire Barrel

Just put on a new ER Shaw barrel for the RPR... Night and day difference over factory barrel. Have about 400 rounds through it today both breaking in and group testing. Factory barrel shot okay (.6-1" 5 and 10 shot groups and depending on ammo) this is Ruger Factory Barrel after bedding...

www.snipershide.com

Interesting. I have run the same test as well. My conclusion was that 22lr ammo climatizes to fast to get solid results. If I bring a box out of the room in a couple of minutes the velocity is the same as the cold stuff.
The accuracy difference is interesting. Makes a guy wonder about bore vs bullet diameter change with temp. Bullet shrunk bore still big?

 

[straightshooter1]

Interesting. I have run the same test as well. My conclusion was that 22lr ammo climatizes to fast to get solid results. If I bring a box out of the room in a couple of minutes the velocity is the same as the cold stuff.

Of course, that's a good point and one that was of concern to me as well. This is why I handled the ammo as I explained in that second post where I kept it chilled in a small tote and pulled a single round out one at a time (even using a gloved hand to do so that my body heat had minimal effect) and firing it as quickly as possible to keep any change in temperature to a minimum as I fired each one.

Makes a guy wonder about bore vs bullet diameter change with temp. Bullet shrunk bore still big?

I have no doubt about the diameter of bullet changes with temperature, but I highly doubt the change is enough for a 50°f difference to have any measurable effect.

Having worked with various metal alloys on aircraft, I'm simply relying on that experience to have that doubt. That's not science, but . . .???

 

[Travelor]

We use a plastic box to keep our ammo warm on cold days. We put a wash cloth in and a hand warmers. The wash cloth is to keep the ammo from contacting the had warmer. Works for us.

 

[308pirate]

What results have you guys gotten with cold weather?

None, because I refuse to go out when it's this cold.

 

[Gleedus]

None, because I refuse to go out when it's this cold.

Id never get any shooting done. 10 months of winter and 2 of poor snowmobiling...

 

[grauhanen]

Magneto

30 minimum I record the 10 at 50 and the 20 at 200. If I really want to check out a ammo I'll do 3 groups at 200 so then I have 60.

I also will/ have done multiple days of same temp to see if I get repeatable results. I do.
All of my temp tests are done rifle and ammo same temp.

my opinion.... 30 rounds I see as a minimum for average speed. SD 50 rounds will have it. ES all of them... lol 50 gives a good idea. Typically batch to batch of 30-50 ES is simular. I dont look at ES much unless I get a a extra large ES in a group at distance.
I've done several hundred of one to see what minimum shows close to average without wasting ammo. Bulk ammo takes more.

More then you asked for I realize. I like details i guess.

Details can be very important and more is often better than too little.

I agree that 30 rounds is a minimum for getting data that begins to be reliable. All too often people chronograph ten shots and draw untenable conclusions.

The Magneto chronographs are reputed to give relatively accurate data. Is this a model that attaches to the barrel? If it is, like anything else attached to the barrel, it can affect barrel harmonics. Have you compared how accuracy is affected when you shoot with it on the barrel and when you shoot the rifle without it?

 

[Gleedus]

Details can be very important and more is often better than too little.

I agree that 30 rounds is a minimum for getting data that begins to be reliable. All too often people chronograph ten shots and draw untenable conclusions.

The Magneto chronographs are reputed to give relatively accurate data. Is this a model that attaches to the barrel? If it is, like anything else attached to the barrel, it can affect barrel harmonics. Have you compared how accuracy is affected when you shoot with it on the barrel and when you shoot the rifle without it?

I dont attach to the barrel

I did some testing with centerfire on or off with heavy barrels I didnt find a universal conclusion.

 

[straightshooter1]

I dont attach to the barrel

I did some testing with centerfire on or off with heavy barrels I didnt find a universal conclusion.

View attachment 7559451

Likewise, I don't attach mine to these barrels either:

 

[Gleedus]

Likewise, I don't attach mine to these barrels either:
View attachment 7559603

View attachment 7559604

What adapter you get to clamp on pic rail?

 

[straightshooter1]

What adapter you get to clamp on pic rail?

It's the one shown on the MagnetoSpeed's website.

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