Cold Weather Testing

[RandallJD]

Planning to sight in my new rifle this weekend (Savage MK II FV, heavy barrel). The temperature in my neck of the woods is supposed to be -17 Celsius / 1 Fahrenheit.

Just wondering what I can expect as I'm new to precision RF shooting - anyone have thoughts on how cold/extreme cold will affect things? Will my grouping change radically from cold barrel to warm?

Any and all thoughts welcome. Suggestions for buying a new rifle will need to be filed with my wife -_-

 

[TOP PREDATOR]

i don't think your barrel "heat" will do all that much unless it's a semi and it's rapid fire, or it's the first "coldbore" cold shooter shot.

i'd be more concerned on hands shivering, and the amount of clothing you'll have on (affecting LOP, eye alignment and cheek weld) vs. any other time of the year.

if you experience 50 deg swings up there between now and summer seasons, you'll probably notice a shift in impact and have to make a slight adjustment.

another thing is if you are using std / subsonic / match ammo that is just below 1080fps you may gain enough FPS in the colder / less humid temps / altitude may sending it over and below the supersonic speed causing the bullet to wobble a little.

 

[TimK]

I chrony tested some Eley Target ammo by placing some in our deep freeze overnight. It measured exactly the same MV compared to room temp ammo, at least with my crappy Shooting Chrony. I don't know how cold the freezer actually was, though. You might be colder.

I have nothing to back this up but a hunch, but I wouldn't be surprised to find the lube gets gooey. Here's what Eley says about their Biathlon ammo.

"ELEY ammunition has won more Olympic medals than any other .22 brand. It’s now time for ELEY to enter into the Winter Olympic shooting discipline with Tenex biathlon. Tenex biathlon is the first specially designed ELEY biathlon cartridge in the company’s 185 year history.

ELEY engineers and technicians have studied bullet and chambering characteristics between 0c and -20c to develop the new ELEY Tenex biathlon cartridge. Tenex biathlon benefits from the key features of Tenex, a flat nose bullet profile with superb performance and accuracy. To improve performance at low temperature the diameter of the Tenex biathlon cartridge is 0.0008 of an inch smaller than standard Tenex. This helps the cartridge chamber smoothly from the magazine through the rifle. Tenex biathlon has an increased propellant charge giving the bullet increased terminal energy and a greater knock down force needed for the biathlon target. Typically ELEY biathlon’s terminal energy is 114 joules, nearest competitor just 110 joules. Tenex biathlon also has a specially formulated lubrication for optimization at low temperature."

 

[jbell]

I find that cutting edge accuracy tends to drop off slightly with true match lubed rimfire ammo when temps drop below 60f and even more so when the temps reach freezing and below. I don't usually expect too much in the very cold, but in good weather I expect well under 1/2 MOA at 50 yards out of my rifle FWIW.

 

[RandallJD]

another thing is if you are using std / subsonic / match ammo that is just below 1080fps you may gain enough FPS in the colder / less humid temps / altitude may sending it over and below the supersonic speed causing the bullet to wobble a little.

Thanks for the comments.

I actually hadn't even thought about the "thinner" air but you're absolutely right. The air will be cold and dry. The lube comments by TimK were interesting as well. I'm going to be shooting CCI mini mags, which I believe use a wax lube...?

Jbell - any thoughts on if there is a "terminal velocity", so to speak, for cold weather? Wondering if temperature makes a difference from 0 downward, or does frozen mean frozen.

I'm hoping to do some hunting by snowshoe this winter so fingers crossed this little Savage is a straight winter shooter.

 

[RandallJD]

Just found your post from earlier in the year:

http://www.snipershide.com/shooting/snipers-hide-rimfire-section/169129-22lr-ammo-temp-test.html

Nice work!

 

[jbell]

I don't know about that, I usually punch paper...

 

[TOP PREDATOR]

shouldn't have too much of a problem with mini mags unless you are a bit further out like 100-150Y.

for minute of rabbit, you shouldn't see a big difference, for consistently hitting X's for score is where all this starts to get important, though with the HV not too much difference at 50Y as it's going to stay supersonic.

i did some testing a few year's ago in cold weather and heating the ammo up on a car defroster and have a pot here somewhere on it with pictures, the POI did change a little, but for rabbit purposes not enough worth being concerned.

 

[terrible tim]

If you see ignition problems, clean the bolt thoroughly of any and all oil in the fining pin channel. Some lubes will thicken in this type of cold and cause erratic ignition.

 

[yoteman]

we have used lapua polar, but our temps, not that cold, somewere north of 32deg
how ever what has been said i find to be true, min of rabbit, clean all lube from bolt an fire pin,
a friend had a bad day on a canada deer hunt last year, nice deer walks out an pukked the trigger
yep nothing happen, bolt an firing pin froze stuck,that night clean all lube off, next day he got his deer:

 

[cjd223]

It never gets "really cold" down here. I do put my match grade ammo in a small cooler along with some chemical hand warmers. It stays nice and warm during our Sniper match.

 

[jbell]

I have also ran some test in the cold with warmed ammo and never found any real difference. However I cant seem to get the same level of accuracy in the cold as I can with it warmer. Maybe it is me but I know several other shooters who have the same results.

 

[jbell]

Here is the test I did in January of this year:

http://www.snipershide.com/shooting/snipers-hide-rimfire-section/169129-22lr-ammo-temp-test.html

Like I said this rifle will easily shoot 1/2 MOA in warm air. I plan on doing this again this year as well but with other 22lr rifles as well.