Failure to ignite powder

[MnMike]

I have been shooting my M95 8x56R with a mild load of Win 748 and all was well. Then it started to get cold here in Mn. Twice out of 6 rounds, the primer would ignite, but the powder would not. I had to whack the bullet out of the barrel with a cleaning rod. The powder (Win 748) was caked together in the front of the case. When lit with a match, it seemed to burn OK.

I found a thread on another forum that said that this is a common problem if the bullet is undersized
or the chamber or the area around the neck is loose. The problem seems to go away if a good factory crimp die is used.

There was also some concern that if the charge would ignite, it would be after it was forced into the neck area and the forward part of the powder would act as an barrel obstruction, raising pressure.

Does anyone have any input?
mike

[Graybeard]

Ya prolly just need a hotter primer. Those ball powders can be a bit difficult to ignite and cold weather makes it worse. Use magnum primers.

[davem270win]

And if the powder density in the case is low, you may need to use filler.

[mangulator]

Graybeard is correct! check your type of primer it is common when using 748 powder to go to a hotter primer.

[Steve P]

You do need a good primer AND nearly a full case of powder.  If your case is not close to being full, dont use the 748. 

Steve