shooting in the cold

[dragman]

I noticed in the extreme cold my shoulder doesn't seem to fire to the same length every time. I check every piece when loading but the last time I shot the fired brass was all a thousands or two shorter than it usually is?? is that common or just an anomoly because of the extreme cold??

 

[Minesweeper3433]

I wonder if it has something to do with the hot brass getting dropped in the snow and ice on ejection? I know brass expands on firing and then contracts after pressure drop maybe it contracts further in cold weather?

 

[dragman]

No ejector so that isn't a problem or a possibility in my case, but it was around -30

 

[Minesweeper3433]

I would guess drastically reduced pressures when it gets that cold unless you are loading up for it. I know hogdon makes all those extreme powders that are supposed to be temp insensitive but -30 I think the powder is telling you no I want to go home.

 

[dragman]

I use my instant indicator and they are always right on the money from 40 degrees up to 90 and the cases always come out really clean. Yesterday was a surprise to be a thousands short and a little dirty. I assumed the brass was just acting up, but I think your probably right since I am not pushing it real hard the load might have had "lighter pressure" due to the temp causing the problem.

 

[Dans40X]

What is your definition of extreme cold?
O degF ambient
Cold air is much denser than 68degF &/or 120degF air.
The load that you worked up in 68degF temps fired at 0degF will produce less pressure & velocity.

Take that same 68degF load & fire it at a balmy -40degF & pressures/velocities decrease drastically, in the neighborhood of 200+ fps in the velocity department.
I work up 65degF/0 degF & -30degF loads for several hunting rigs.
Our match temp cut off is -20degF.

The temperature in-sensitive powders raved about today is all BS when shooting in colder temps.
Shade your ammo from direct sunlight w/ a hat & you're basically good to go.
At -40 ammo will usually require a touch of bullseye to light 70+ grs of powder.

Altitude/Humidity & Dew Point are miniscule compared to dealing w/ extreme temperatures.

Deal w/ 150degF temp swings of the arctic-you don't know what extreme is!!

 

[jelrod1]

Dang, at minus 30 I'd be happy if my cases were the only things coming up short

I agree with the others less pressure being the cause.

 

[queen_stick]

What is your definition of extreme cold?
O degF ambient
Cold air is much denser than 68degF &/or 120degF air.
The load that you worked up in 68degF temps fired at 0degF will produce less pressure & velocity.

Take that same 68degF load & fire it at a balmy -40degF & pressures/velocities decrease drastically, in the neighborhood of 200+ fps in the velocity department.
I work up 65degF/0 degF & -30degF loads for several hunting rigs.
Our match temp cut off is -20degF.

The temperature in-sensitive powders raved about today is all BS when shooting in colder temps.
Shade your ammo from direct sunlight w/ a hat & you're basically good to go.
At -40 ammo will usually require a touch of bullseye to light 70+ grs of powder.

Altitude/Humidity & Dew Point are miniscule compared to dealing w/ extreme temperatures.

Deal w/ 150degF temp swings of the arctic-you don't know what extreme is!!

You're using a bit of pistol powder in your loads to get consistent ignition in extreme cold?

 

[nosualc]

At -40 ammo will usually require a touch of bullseye to light 70+ grs of powder.

Really?

I'm not sure I've got the cojones for that…

-nosualc

 

[Raythemanroe]

It's cold out, your coming up short. Don't worry it happens to everybody some day ;D

 

[CatShooter]

At -40 ammo will usually require a touch of bullseye to light 70+ grs of powder.

You're kidding, right???

 

[dragman]

Dang, at minus 30 I'd be happy if my cases were the only things coming up short

I agree with the others less pressure being the cause.

You aint lying right there!

 

[Syncrowave]

At -40 ammo will usually require a touch of bullseye to light 70+ grs of powder.

FWIW, according to my Speer manual,

"...pressures may increase dangerously under extreme cold (-20°F) conditions with loads of double-base powders [like Bullseye]. Do not fire cartridges that have been exposed to such cold. They will be safe if placed in pockets and warmed with body heat."

 

[Nalgi]

this is why IMR 8208XBR was developed. To lessen the effects of cold on velocity

 

[LHSmith]

this is why IMR 8208XBR was developed. To lessen the effects of cold on velocity

And I always thought it was Hodgdon's failed attempt to replicate the famous "T" powder (Thunderbird T-322) ....the Holy Grail powder used in the 6 PPC for Point Blank BR.