Distance ?

 

50yds

 

Did you store your ammo in the vehicle the day before you shot it? I would try leaving it in the house, keep it warm.

My .o2

 

It was in my pickup in my heated shop. Then 20 minutes to the range. I’m not too worried about it, just learning what’s what. Weather matters, I was kinda thinking I might see some fluctuations when I got heading out. Fun morning still. I know what all those lots can do in warmer weather. All good.

 

Most of those groups look pretty impressive to me.

 

ammo next to your body, chest or pants pocket, or in a outer pocket with a warmer packet?

 

If I’m gonna try to replicate warm weather performance I’ll probably have to try this or something, yeah.

 

You’re not going to miss with this combo seems to me like groups are just fine

 

Interesting! I wouldn’t have thought temperatures in the 30’s would have caused the misfires especially with quality ammunition.
Now I know why they make Biathlon ammo.

 

Apparently my ammo is less fond of 34 degree weather?

I predominantly shoot SK ammo through my 457 Varmint. It likes Pistol Match best at sub 75 yards and Rifle Match best at greater than 75 yards. I do most of my practice with Standard Plus.

All of my SK ammo shoots worse when its cold. Biathlon is designed to shoot when its close to freezing, but even it shoots better when it's above 35-40 degrees. I notice a drop off in group sizes with Rifle, Pistol, and Standard starting at about 45 degrees and getting worse as the temp drops. 45 vs 60+ degrees is subtle, and may be all in my head or that I don't shoot as well as I start to get cold. But by the time you hit 40 degrees, the opening up of the groups is more noticeable and measurable, and I cannot attribute it to me shooting worse versus the ammo not shooting as well.

I noticed the same when I used to practice with CCI SV. It's opening up of groups and loss of accuracy was worse than SK's in my experience. My rifle isn't a fan of Eley, so I don't know if it also opens up at lower temps.

Your groups look great! Especially considering the temperature. Rimfire isn't centerfire, and averaging what looks to be between .6 and .7 inches edge to edge at 34 degrees is solid!

 

Cooler temperatures cause the average MV of rounds to be slower (warmer temps increase MVs).

While shooter performance can be affected by cooler temps, the ammo performance on target need not be affected.

Below is a target shot last November when the temperatures were in the mid-20s F. Ten-shot groups at 100 yards (40 rounds). The ammo was Midas. I keep my ammo at the ambient temperature.



Biathlon ammo isn't necessary. It's main difference is that it's faster than standard rifle ammo.

SK Biathlon Sport is the same as other SK ammo nominally rated at 1106 fps, which are SK Long Range Match and SK Pistol Match Special. Biathlon Sport is produced at the same time on the same production run on the same loading machines and is only a different grade of 1106 fps-rated SK ammo. (Long Range Match is top, Pistol Match Special is bottom.)

 

@jaia and @Drpietrzak

I know you guys collect a lot of data when you shoot.

Do you have any observations you could share regarding the effects of temperature on accuracy?

 

When I am shivering I tend to miss more!

jaja and others would be the ones I would trust the data more from me. My collection, on temperature, is currently more anecdotal than data based. My perception, which is as flawed as everyone else's, is that the ammo I use seems to function across rifles more consistently in 50*F to 80*F. As temperatures get outside that the changes in velocity seem noticeable to me (perception). I recently acquired a chronograph that is truly portable so I am beginning to outline the protocol to start a more data based examination. It is also the time of the year here where I can perhaps get a baseline as it moves into winter. I think, I do no know, that there are some changes with velocity and as such ES and SD. I will know more in a year I would guess.

I would suspect it will be as hard as every other thing in this area to really parse rifle changes and other elements from ammo changes. For example, shooting a rapid 25 round card on a rifle barrel that is at 95*F seems different than that same barrel at 0*F. The effect of mirage seems different to me as well.

 

I’ve found that cold temperatures can cause a combination of things to happen.

Frozen primer compound might cause inconsistent ignition…

Fast burning rimfire powder seems to be temperature sensitive = velocity decreases...

Bullet lube, the wax, is no longer as fluid and possibly even frozen could cause more or less friction in the bore shot to shot…

Contraction of the metal in the rifle, tightened tolerances…

Higher air density that would impart more external forces on the bullet both with wind deflection and slowing the bullet more.

 

I can't shoot good regardless of temperature. If it's hot, I'm dripping sweat and messing up. If it's cold, I'm shivering and messing up. If the weather is perfect, I'm probably at work.

 

Change in temperature affects burn rate.
At lower temperatures expect slower burn rate,
lower peak pressure resulting in lower muzzle velocities.
High temperatures increase burn rate, increase peak pressure
and bumps up the muzzle velocities.

I show worse accuracy at lower temperatures
with larger velocity spreads. Some of that loss
of accuracy is me reacting to the cold with increased
body movement. I do better with temps above 65
degrees F.

I show more strays on cold days, even with calm winds.
My best scores are when temps are in the low 70's F, no wind.

 

Agreed. Seems everything is magnified with rimfire. My centerfires might drop 30 fps when it’s 10 degrees, but the accuracy is less affected. Percentage wise though when you drop from 1075 to 1040 I suppose it’s quite a bit more important vs 3080 to 3050.

 

34 degrees as in Fahrenheit? It’s barely October, where do you live that it’s already 34 during the day?

 

I thought the same

 

Did a test two years ago, put some SK LRM & Eley Match in the freezer... then took it out to the range in a cooler with ice packs... but it was August and according to the cheap IR thermometer it was above freezing when finally fired. The 115* stuff sat on the dash in Florida sun for an hour+
Heat index was 99* here yesterday 🔥

 

So weather causes a velocity variation?

 

If I shot groups like the OP did when it was cold I would place my daily shooting ammo in the freezer overnight before going shooting.

 

Your groups look great. We have found lower temperatures definitely will affect ultimate accuracy potential. When it to get cold, we leave our boxed 22 ammo on the dashboard with the windshield facing the sun-works great!

 

You said you had some failure to fire on first try but had ignition on the second. Do you use lube on your bolt or oil in the barrel then vertical in the safe? If so it may be thicker when cold which can cause failure to fire and light primer strikes that can also give inconsistent velocities. When I had my shop open I saw a few each year. Shot fine when sighted in then hunting in November saw a deer and click. Clean the oil from the bolt and problem solved.
Good luck.

 

Yeah when I’m done cleaning I put a patch of kroil in it then a dry patch. I clean the bolt, oil with Lucas. Store vertically. Good point though, more for me to keep an eye on. Thx.

 

It has been a while since I shot small bore competition but as I recall, my match ammo started failing at 67 degrees F from our normal 90 or so ambient temp in NW FL. So I kept my ammo in a small cooler on the line to maintain a constant temp. If in the desert at 110-130 degrees , I put a layer of ice in the bottom, with a couple layers of towels above the ice so the ammo in the cooler stays at about 80-90, then I only took five rounds out at a time. The Russians had several 22 LR match ammo names made for different harsh conditions but when we stopped imports, the Russian ammo disappeared. The Russian small bore shooters are well equipped with guns and ammo.

 

Could try and get an ice fishing tent with a propane heater in it. Done this with centerfire.

We also see -40 up here in northern Alberta. Celsius and farenheight are about the same.

 

That’s a good idea. I have an insulated igloo ice fishing hut with a heater.

 

Nothing to do with rifle but I shoot action matches every month that include bowling pins and steel plates. Our range isn't heated. When the temperature drops alot of semi auto 22 pistols seem to really struggle with reliability. I keep my loaded mags in my pocket until I shoot.

 

It was very cool overnight and when I began to shoot this morning it was - 3.0 degrees Celsius (26.6 deg F). A lttle over an hour later it was -0.7 degrees Celsius (31.5 deg F). More important, it was very calm (a key reason I went out today). I shot ten ten-shot groups at 100 yards with Midas. The ammo was kept at the ambient temperature.

The ten group average was just under 0.900". This is about as good as can be expected when it's warmer. Cooler temperatures affect shooters more than ammo performance.

 

It was very cool overnight and when I began to shoot this morning it was - 3.0 degrees Celsius (26.6 deg F). A lttle over an hour later it was -0.7 degrees Celsius (31.5 deg F). More important, it was very calm (a key reason I went out today). I shot ten ten-shot groups at 100 yards with Midas. The ammo was kept at the ambient temperature.

The ten group average was just under 0.900". This is about as good as can be expected when it's warmer. Cooler temperatures affect shooters more than ammo performance.

Cooler weather affects me, in a positive way. Glad your ammo held up.

 

It's a fun time shooting in the winter in MN.
I don't shoot my hi-$$ ammo in the winter any more.
Have tried a few times and my accuracy & precision was not the same as summer
shooting USBR Match's here on RFC @ 25 & 50 yards.
Just my experience....but maybe I gave up to soon.
My dad was on the Korean DMZ in the winter of 53-54 in a wall tent.

 

[QUOTE="BobCole, post: 13849878, member: 103931.

I learned from the Sheriff Walt Longmire series of books, of which I have all of them! LOL!
[/QUOTE]

The Longmire series is great