Primer Stability Question

[SwampWolf]

I'm aware that changes in temperature can change the performance of gunpowder. I'm wondering how stable primers (or primer compounds as found in rimfire ammunition is) are when it comes to temperature changes. For instance, will cold temperatures cause ignition problems with .22 rf ammunition? Thanks.

 

[Drail]

Do you mean after exposure to or when firing in cold temps? My experience has never shown any problems with either at temps that a human can survive. Most lubes would disable a semi auto firearm exposed to freezing temps before the primer or powder would. I have talked to numerous Veterans of the Chosin Resevoir campaign that reported weapon stoppages from frozen lube.

 

[rcmodel]

+1
Cold has no effect.
Extreme daily temp swings might due to condensation inside the cases.

Primer compound is much more stable then smokeless powder.
It is manufactured as a wet paste, put in the rims or center fire primers as a wet paste, and then dried and loaded.

It can get wet again, and be fully functional again as soon as it is dried out again.


The worst that can happen with rim-fire ammo is the compound cracks and pieces of it fall out of the rim.
Then, you will have misfires if the missing section is hit by the firing pin.

IMO: Missing rim-fire primer compound is more likely to be caused by poor manufacturing, or very rough handling then normal storage conditions.

If the conditions are comfortable to you, the ammo could last way longer then you will.
That means not on the dashboard of your car in the hot sun, or in the bottom of your fishing boat in standing water.

rc

 

[SwampWolf]

Thanks for the informative replies. You both have pretty much answered my question.

 

[W.E.G.]

I think the often-heard complaint about .22 rimfire misfire issues in cold weather is more a function of the generally filthy condition of most .22 rimfire rifles than any issue with the ammo per se.

Gunky wax/lead buildup in the area of the firing pin can severely slow a firing pin as the gunk hardens in cold weather.

Seems that there are more complaints about "cheap" .22 ammo failing more often than top-shelf ammo. Again, that is probably a reflection of the volume of use of the guns where shooters are blowing through lots of "cheap" ammo.

Don't expect many misfires with your .22 in cold weather if it is clean, and the ammo is good quality.