rimfire in the cold, what do you know about it?

you really have me wondering now I haven't done much rimfire in the cold I am hitting the range this weekend we have lows of -20 coming so depending on wind I will let you know what I find if its calm I cant shoot inside 300Yards at my girlfriends parents though so its gonna have to be calm to learn anything. I was shooting 3-4" groups in the summer with my 10/22 so we will see what I come up with.
 
Now 20 below is cold! I find that after the temps hit the low teens and below I start having issues with trigger control. Not to mention loading magazines BLOWS!!! Good luck and keep us posted.
 
Got out and did some more shooting since it was 40ish degrees today with a light wind.

Was shooting Wolf Match Extra and minus one group where it was a mishap with six rounds and a pulled shot, all my groups were up .750 from outside edge to outside edge. This was better than the group I shot with Eley Match EPS. Now I've gotta get some Center-X :-D!

.680
.505
1.167
.688
.736
.500


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I finally got a chance to shoot the RWS R-50 and R-100 Friday, temp was 31 or so. Actually felt pretty nice after this winter. This was the first outing for my CZ 455 with the new Lilja barrel. ( will post results of the 5/6 challenge tomorrow). Ran about 30 rounds of RWS Rifle Match to get sighted in and start break in. Then shot about two boxes of R-50 with great results followed by a box and a half of R-100. I had been shooting Eley Match before this with mixed results in the cold, seemed pretty inconsistent, which prompted the RWS experiment. The R-100 was defiantly hotter, shooting a little,higher than the R-50 and did not seem to run as consistent. But that could have been me at the end of the day. Long short short, the R-50 may be my new go to match ammo.
 
Polar shooting

Some additional thoughts on shooting in the cold. With the tiny amounts of powder in a 22, the cold means that the combustion gases reach lower max temp and pressure, thus has lower muzzle velocity. The bullet passing thru the air is governed by fluid dynamics and the heavier, thicker air increases drag, slowing the bullet faster and causing the wind drift and spin drift affects to increase. That is possibly why the slower twist bbl mentioned earlier is slightly more accurate in the cold. It is spinning slower and thus experiencing less spin drift.

I shot a lot this past winter in temps from the high 40's to down in the low 20's. It stayed cold so long that I actually got kind of used to it. I agree that a 5mph wind at 20 deg F has more impact on accuracy than the same wind at 80 deg F. This winter my best groups have been with Eley Black when the temps dipped into the 20's. All the SK/Wolf/Lapua ammo seemed to shoot more erratic and was affected more by wind than the Eley stuff in very cold temps. That was with my rifle (your mileage may vary). The Lapua did shoot faster and when I switched from Lapua to Eley it would take 8-9 clicks up on my scope to correct for the lower POI of the Eley ammo. Once the temps get above 40's I am seeing big improvements in the precision of the Lapua ammo. I believe that most of this is due to the shape of the bullet and the type of lube used on the Eley vs Lapua. Cannot prove it though.

For paper punching, Lapua/Wolf/SK all cut smaller more ragged holes in the targets than the nice round holes cut by the new Eley bullets. If you are scoring best edge this can make a difference, although small. This has nothing to do with cold but was something I have noticed. When shooting for small tight groups, the opposite is true. The smaller holes of the Lapua ammo makes the groups look smaller, when in reality, they are not, if we score them correctly. I think it has fooled me at times into thinking my Lapua ammo shot better.

We are all shooting outside. I shot the best 22lr groups in my life this past winter in 20 deg and 30 deg weather. The best match ammo is still going to have velocity deviation and if we had a perfect gun with perfect aim, the best it will shoot is about 0.160" just from ammo variance alone. Yes, some of us, me included score 5 shot groups at 50yds that are smaller than that, but if we shot that perfect gun for 50rd groups, it cannot get better than about 0.160" c-c groups with the current state of the art ammo. That is a theoretical best. I saw a recent post where a Blieker shot indoors fired a 40rd world record group at 50m that was 12.8mm which is about 0.500". I am pretty sure it was measured edge to edge, not center to center, so that is closer to the reality. It broke a record that had stood for several years by only a tenth of a mm. I think where cold affects us is that it magnifies the velocity variance impacts on accuracy as well as the wind affects, thus making that theoretical best open up to something larger. Unfortunately none of us have a "Perfect Gun", let alone perfect aim, and the wind, well even on a calm day, it is not always insignificant. Hey if it was easy, everybody could do it.

Irish
 
RWS

I finally got a chance to shoot the RWS R-50 and R-100 Friday, temp was 31 or so. Ran about 30 rounds of RWS Rifle Match to get sighted in and start break in. Then shot about two boxes of R-50 with great results followed by a box and a half of R-100. I had been shooting Eley Match before this with mixed results in the cold, seemed pretty inconsistent, which prompted the RWS experiment. The R-100 was defiantly hotter, shooting a little,higher than the R-50 and did not seem to run as consistent. The R-50 may be my new go to match ammo.

Looking forward to seeing your results from the RWS. I had a few boxes of RWS R-50 about a month ago. I found it to be very consistent. Groups were round in shape and almost never had a flyer. I liked it. It failed to group as small as some of the other ammo in my gun but they are all different. The consistency was very good. This rimfire stuff is addictive. It still amazes me how much difference a change in ammo makes with a given gun. If I am zeroed with Eley Black 1045fps and switch to Wolf or SK or CX ammo, the POI goes up 1/2" and left by about 1/8". I suppose this is mostly from the higher velocity of the Lapua ammo.

Here is another thought on cold weather accuracy. The speed of sound is lower at colder temps. Where is is about 1125 fps at 68 deg F, it drops to about 1085 fps at freezing. Most of the std vel ammos are getting muzzle velocities of about 1080 or less but I do know that some of the Lapua ammo (and others) was going across the crono above 1100fps in some guns. Drop the temps into the teens or 20's and there is a high likelyhood that some ammo is exiting the muzzle at just above supersonic speeds and then slowing to subsonic before reaching the tgt. That trans-sonic transition is enough to induce a bit of accuracy variance in the bullets me thinks.

Example: At 24 deg Fahrenheit the speed of sound is 1078.068 fps. Our test ammo exits the Muzzle at 1150fps is going to be just above the supersonic speed and will slow to 1078fps at about the 30yd mark. By the time it hits our tgt at 50yds it will be down to about 1039fps. Since the trip from muzzle to tgt only takes about 0.1 seconds, it does not have much time to re-stabilize after the transition back to subsonic speeds. Now 1150fps is a good bit hotter than most Std vel 22lr ammo. My theory is that for those that do exit the muzzle at speeds in excess of 1080, they may be experiencing the affects of this type of transition. Others that are well below these speeds do not. The affect that this has on the group size of the rifle is likely only noticeable when shooting highly accurate guns from a very stable rest such as tractical/prone or benchrest type shooting with higher power optics since many of the other variables are minimized.

Now I have not chronoed any of the Polar Biathlon ammo, but it does seem to have a higher muzzle velocity based solely on its higher POI. Maybe the manufacturers are intentionally raising the speed of their cold weather ammo seeking to keep the bullet supersonic from muzzle to the tgt at 50 meters? That could be possible if the temps are hovering below zero, but unless they are starting at about 1200fps or better, they will still pass thru the trans-sonic speed before reaching the tgt. The probability of this increases as the temps go up since the speed of sound will also increase with temp. Maybe for biathlon the affect is not sufficient to be significant? Their tgts are bigger than a typical benchrest bull and the issues the biathletes must overcome are less from ammo variance and more related to the ability to aim well while standing all with elevated breathing and heart rate. All while using aperature sights. My hat goes off to them as I cannot do what they do even without the exertion of cross country skiing.

Irish
 
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Here is another thought on cold weather accuracy. The speed of sound is lower at colder temps. Where is is about 1125 fps at 68 deg F, it drops to about 1085 fps at freezing. Most of the std vel ammos are getting muzzle velocities of about 1080 or less but I do know that some of the Lapua ammo (and others) was going across the crono above 1100fps in some guns. Drop the temps into the teens or 20's and there is a high likelyhood that some ammo is exiting the muzzle at just above supersonic speeds and then slowing to subsonic before reaching the tgt. That trans-sonic transition is enough to induce a bit of accuracy variance in the bullets me thinks.

Example: At 24 deg Fahrenheit the speed of sound is 1078.068 fps. Our test ammo exits the Muzzle at 1150fps is going to be just above the supersonic speed and will slow to 1078fps at about the 30yd mark. By the time it hits our tgt at 50yds it will be down to about 1039fps. Since the trip from muzzle to tgt only takes about 0.1 seconds, it does not have much time to re-stabilize after the transition back to subsonic speeds. Now 1150fps is a good bit hotter than most Std vel 22lr ammo. My theory is that for those that do exit the muzzle at speeds in excess of 1080, they may be experiencing the affects of this type of transition. Others that are well below these speeds do not. The affect that this has on the group size of the rifle is likely only noticeable when shooting highly accurate guns from a very stable rest such as tractical/prone or benchrest type shooting with higher power optics since many of the other variables are minimized.


Irish

This actually had slipped my mind entirely! In my most recent cold test I noticed some cracking and those groups were noticeably affected. The best lot that I pictured in here had none supersonic. That could explain it.


On a side note, I knew a smoking hot cheerleader that went to college in Moorehead... She would have kept the entire winter warm!
 
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Just a FYI on Polar Biathlon ammo.

The barrel on my 1827F is 21.65". In the summer temps of 80-85 degrees the velocity was 1090-1095 fps. It slowed down to 1050 - 60 fps or so in temps of 30-40 degrees.

I've learned that when shooting longer distances for a 22 I have to either shoot over the chrono and/or true up the dope again (right then), to successfully hit 2 moa steel at 200-300Y and match come ups. Usually the ammo is in the drag bag out in the truck so it's subject to temperatures. I should use my centerfire trick and keep the loaded mags in my pocket to see how stable the velocity becomes. Still experimenting...I haven't even used the ammo temp function in the SHOOTER program to see how well that works. Fun fun, I'll keep working at it.

Wolf MT gives approx 1050 fps in that rifle during summer. I haven't shot it in my rifle this winter to know what velocity is gives in cooler temps.
 
Interesting posts by both Steve123 and Irish. I do not have a chrono, but I can tell you what has been the most consistent grouping ammo for me. Bear in mind that I live in Duluth, MN so the weather is very schizophrenic at times. For 50 yard groups in the winter months SK Standard Plus delivered the best accuracy, the smallest group measuring .217. For 100 yards I shot a target with Wolf Match Extra where my average was around .713 and smallest was .500; while my groups averaged with Eley Match EPS @ .934 and smallest was .665. This fall in late November I did shoot a 5 shot group with Eley Match EPS that measured .244 @ 100 yards. I think that for me the Eley maybe better in fairer weather, while the SK, Wolf, and I dare say Laupa shoot better in the colder temps. This spring and summer I hope to determine the results for my rifle, I'm still working on form and it is getting better.
 
Some great info guys! I am really digging it!!

Interesting on the speed of sound being slower in the lower air temps, I have not given it any thought. I am shooting a 26" barrel that is running the Center X around 1060fps in 25ish degree air temp, so maybe that is why I am not seeing as much of an effect on my accuracy. I am going to be thinking about this much more now. Thank you Irish and Steve!
 
This actually had slipped my mind entirely! In my most recent cold test I noticed some cracking and those groups were noticeably affected. The best lot that I pictured in here had none supersonic. That could explain it.


On a side note, I knew a smoking hot cheerleader that went to college in Morehead... She would have kept the entire winter warm!

You gotta love a college town with a name like "More Head". I knew some of them cheerleaders too. Wow... :cool: But I was more partial to the majorettes, lol. Kentucky is the home of Pretty Horses, Smooth Bourbon and Fast Women, or was that Fast Horse, Cheap Bourbon and Pretty Women? I forget.

As for the supersonic stuff, unless it is very cold and we are getting muzzle velocities in excess of 1080, it will be hard to blame a flyer on transonic wobble. But, it makes a great excuse to tell your shooting buddies when you muff a shot. Something like, "Damn, did you see that? My bullet went supersonic and then started to wobble bout halfway to the target. Darn trans-sonic shock waves done went and spoiled my shot."

Irish
 
Being that I switched from my 26" to 16" barrel, I can see it leaving the barrel a fair bit faster. I'll have to chrono it for the actual numbers though. A alway shoot with my can on also so I know it was definately making a crack and I've never had that before.

Just checked; speed of sound was about 1067fps on the day I was shooting. Quite possible the Tenex was hanging very close to that speed.
 
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Going Ballistic

Being that I switched from my 26" to 16" barrel, I can see it leaving the barrel a fair bit faster. I'll have to chrono it for the actual numbers though. A alway shoot with my can on also so I know it was definately making a crack and I've never had that before.

Just checked; speed of sound was about 1067fps on the day I was shooting. Quite possible the Tenex was hanging very close to that speed.

This is entirely possible that the 10x is going supersonic when it is that cold. I have seen 10x boxes that were printed with 1079fps as their test velocity. Check your lot to see. That does not prove it went SS, but will be a strong indication. Barrel length, bore size, taper, how well it was lapped all impact the actual velocity as well as ambient and bbl temperature (my gun always shoots a little faster from a cold bore for the first 3-5 shots).

Most lots of 10x are intentionally loaded slower than that. I just checked the current listing of Eley 10x and Eley Black from my ammo supplier, to see what their test vel was listed as. Out of 7 lots of 10x, only one was loaded above 1067fps. Most were at 1045-1049. The Eley Black was slightly faster. Out of 15 lots, eleven were rated above 1067. My current lots of Eley are both rated below 1050fps which may explain why they are still shooting ok in the cold. Like you stated, it is easy to hear the sonic "crack" if it is going ballistic for even part of the trip down range. I am sure my Eley ammo is not. In fact, I was shooting the other day in the cold and two fellows who were at my range and had never seen my rifle remarked about how quiet it is. They said the bullet made more noise when it hit my target backing than it did when I fired the gun. They were right. The plastic backing was cold and brittle and made an audible pop with each hit.

My rifle has a 28" bbl which enabled the peep sights to have a longer radius for accuracy. This is no value when shooting a scoped rifle. 22lr ammo has reached its max velocity by the time it has traveled 16" to 18" down the bbl and has been proven to actually slow down when traveling down longer bbls. The longer barrel only adds weight. I have a shorter 22 that I hunt with and use for sporter matches. Its bbl is 21-3/4" long and often shoots faster muzzle vels than my tgt rifle. Keep in mind that when it is cold enough for the speed of sound to be 1067fps, then your ammo could be right on the edge of going ballistic with some shots going supersonic and some being subsonic. I would expect this to be far worse than if it was all going supersonic. It could also explain my experience this winter where I would shoot 4 shots into one hole and then have the 5th shot go flying off with an unexplained flyer. It was mostly with Lapua ammo but that ammo shoots faster in my gun.

Irish

P.S. Temp is the #1 variable that affects the actual speed of sound but most calcs neglect some of the other smaller variables such as barometric pressure, altitude, humidity, etc. So, even when we know what it is supposed to be, it can vary slightly. Like if the sun is shining but part of the range is shaded, or your range is in Denver, blah, blah.
 
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...Its about over for this year! :)

Been an long cold winter this year and I am looking forward to some warmer weather. Thanks all for contributing to this thread, it kept me out there shooting when I may of pussed out.
 
Crap on a stick (I love quoting Big Bang Theory).
So yesterday was forecast to be the first nice day of the spring with temps forecast for 8c (about 41F I think) and calm winds.
Took the afternoon off. The boys are on spring break so we headed to the range.
Got there about 1PM.
Yes, it was about 8c...but instead of calm there was a north wind that measured 20mph gusts from the north that made it feel damn cold, plus made good groups impossible.
Man, this winter just doesn't want to give up.
 
Cold

Who is the butthead that dredged up this thread?? It just reminds me that winter is coming. I am with Yote. Need more anti-freeze. It will be a cold wave in KY this weekend with highs in the 70's, lol. Well it feels cold after a summer of 90's and rain everyday. More like southeast asia than the bluegrass.

Irish
 
Who is the butthead that dredged up this thread??
I-participated-in-the-afforementioned-action-to-accomplish-the-lulz.jpg
 
I know hot and humid too, I grew up in North Georgia. I have spent plenty of days shooting sweating so bad I could hardly hold on to my rifle and ammo. I think I can deal with the cold better. Maine is a good place to shoot, highs in the 90's with plenty of humidity and lows well below zero so we see it all.

Off the rimfire subject but here long range shooting is interesting. We shoot slightly above sea level and have density altitudes from 2500 above sea level to 2500 below sea level. It really shows you what air can do to your shot.

None the less, it's almost time to get the shovels out so we can did a firing position out of the snow.
 
On the opposite side of the temp spectrum I found out Lapua Polar Biathlon doesn't shoot the best in July and August. Last months match I was only 1.7 mils to 100Y so speed must have been 1100 fps. I might as well buy a case of Wolf or SK for summer time.
 
Hard to say, however the 22 Mags are typically not as accurate as high end 22lr. So what gains you may get the accuracy probably will not be as good as "impaired" quality 22lr. But that is only a gut feeling, I could be completely wrong.