Does cold increase pressure!

[Daveinthebush]

Doesn't sound right, I would think that heat would.  But lately the last two times to the range, using loads that I have used for years in the case of the .35 Whelen, same components, the pressure was a bit high.  Just slightly flattened the primers and flowed a bit around the firing pin indentation on the primer.

Same load I have been using for  18 years.  It was about 15 degrees, not bad for AK.

[Daveinthebush]

Under extreme conditions up on the Bering Coast we would wash the action in gasoline and then througly dry it.  Then we would take it out-of- doors, fire it a few times, and leave it hanging outside.  

I can hear the screams on the site already.  But were talking -20 to -50 below "without" windchill!!!!!! And, traveling sometimes by snow machine 150 miles to get a caribou. :eek:

[BruceP]

Dave You said you were using the same components. Did you mean the exact same, as in from the same can of powder; primers; and brass. If it is the same kind of powder but a different lot or even the same powder lot but different brass, it is possable that is the cause.
BruceP

[Mikey]

Dave:  Cold weather reduces pressure.  Velocites have been known to drop almost 100'/sec in the cold.  I would look to some other cause for your flattened primers.

You mentioned that this is the same load you have been using for a number of years.  Same brass?????  Were you shooting reloads when you noticed the problem?  If so, how many times were those cases reloaded?  Your brass may have 'aged' a bit and possibly the primer pockets became a bit loose but I wouldn't look to the cold as the cause.  

BTW, 15 in AK is pretty good.  We had it to zero here last night and it was pretty nasty.  But, my new snowthrower worked really well.  Now if I could just outfit it with a scabbard I would be real happy.  This is Mikey.

[Dand]

to pick up from Mikey - are the bullets EXACTLY the same diameter?  Production runs can vary a bit and sometimes there can be slight design changes that aren't advertised or obvious.

Is all the lube off your cases and out of the bore?

Finally, I think Winchester/Olin discontinued the ww 630 due to erratic performance in the cold.  You might email your powder manufacturer.  But as you  know 15 ain't even beginning to be cold.

Just some ideas.  It was a bit below 0 in parts of Bristol Bay  this moring. More like normal winter - sure don't miss the -30 to -40 of last year at this time.

[Daveinthebush]

I have probably gotten into some bad habits like assuming that all components are manufactured the same evey time.  I have gotten into the habit of just doing the same thing I did last time and not worrying about in a different lot of powder is the same actual stuff.  Next time in Ancorage I am going to buy bigger containers of powder so I  won't have to worry so much.  A 1 lb. can costs $28 over here.  Should be a lot cheaper by bulk in Anc. As much as I shoot even buying bluk bullets from Midway would be the way to go.

Thanks guys

[KING]

Hey DAVE !!!!!!!  Did ya ever find out what the problem was with that rifle of your a couple weeks ago that was getting lousy groups.  Im kinda courious.  King

[Daveinthebush]

I got the.243 fairly straightened out.  I just need to sit down when it is warm enough to try for some better groups.

The .35 Whelen I guess I need to be more careful with.  I am used to just using the same components without working back up to the loads even though there might be differences in the batches of bullets and powder.  

Another possibility would be to buy a certified weight to check the scale with.  I weigh each load individually.

Some else posted above that the firing pin might not be hitting hard enough in the cold and the primer is pushing back because of that, possibility.  


I think the best solution is to buy a new rifle for Christmas and see if I have the same problems with that. :grin:

Thanks for checking, the .35 is going deer hunting on Prince William Sound next week if I an get the boat out.

[Lead pot]

Hey Dave> youall gota clean it once in a while and git the mud and ice out barrel once a year and if that dont work send it my way I dont wana see you getting hurt :-D Lp.