Extreme Weather Testing of SML components and singles

I wonder if an Arrowhead plug would do that? Or one of Jeff's??

I think the inside of a good deep freezer is -15 degrees or there about a... So I think you were colder than 8 degree...

Scat,

In my experience, and others at our deer camp, single charges of H4198 are completely reliable with standard savage breech plug and Fed209A primers in a stock Savage ML10.  One guys uses IMR4198 and one guys uses CCI Mag primers.  No-one has issues in the cold.  Not once. Been many, many laymans tests done by myself and several friends to have this confidence.
Guns left loaded outside over night in single digits.  Hunting in same temps.  The biggest things I can say matter?

1)  Do not swab with lubes.  If you have to swab, dry swab.  Do not use lubes on your plug...use tephlon tape.
2) Have a relatively clean breech plug orifice
3)  When not hunting, always keep a spent primer on a closed bolt
4)  Always have a barrel condom on.  Never take it off and shoot thru it with confidence.  Won't be an issue on targets or game.  
5)  Have a load that loads very tight and always tamp the load with something.  At the bench, this could be all sorts of things.  A small hammer with the rod protected by a glove.  In the field it could be a small, large diameter branch used as a hammer.  Yes we do strange things in the field under pressure to get the same thing accomplished.
6)  If trying for maximum performance, use enough powder in the single you are using.  If you are using a single, like H4198 to get speeds under 2300 fps, you are not using the right powder.  Go to a Savage recommended powder for those speeds.
   a) with 250 gr bullets, do not use less that 74 gr. H4198
   b) with 300 gr bullets do not use less than 70 gr. H4198
7)  If trying for light loads, straight "booster" powders like 4759 go bang with very light charges.  Heck, that's the type of powder that guys claim make their main charges go off in the cold!

Guys that seem to need duplex, I think,  have other un-quantified reasons why they experience the occasional misfire.  

In your test, I would worry that you took it out of the freezer and waited 20 minutes to shoot it when it was 50 degrees outside.  Could get condensation in places without certain protections.

Either way, I do not worry after a long time of trying to get failures, that the cold temps prevent good ignition with a stout load of H4198 using the criteria's above.  It just works. 

Hope this helps the few of us that still live in the Savage stone age!  LOL