Author Topic: Loose Primers on Reloads (Read 481 times)

miked · « **on:** June 11, 2006, 04:09:56 PM »

I have a 338 mag barrel for an Encore. With reloads about 3 grains below handloading manual maximums I am developing loose primer pockets. By that, I mean that upon taking the cartridge out of the barrel the primer just falls out of the primer pocket. Cases appear to be intact, no cracks or separations. The gun opens without any apparent binding. Accuracy appears to be good; less than one inch MOA. This is a new custom barrel. Barrel to frame gap is about .006. Headspace, with these partially full length sized cartridge cases, is probably .006, also. By that, I mean that the cartridge case head is flush with the barrel base.
1) Would this be considered a case of excessive headspace and could this
be the source of primer pockets expanding at below max charges?
2) Any other speculations are appreciated as are possible resolutions.
Thanks

Grumulkin · « **Reply #1 on:** June 11, 2006, 04:35:31 PM »

Excessive head space would not cause loose primer pockets but things like head separation. The cause is either a batch of soft brass or loads of excessive pressure. I would back off on the load a bit.

CyberSniper · « **Reply #2 on:** June 11, 2006, 05:46:39 PM »

You might also try another brand of brass, then work back
up to the load you are using now. See what that does.

huntswithdogs · « **Reply #3 on:** June 12, 2006, 07:49:14 AM »

I'd try another batch of primers and/or brass. I've had problems with both recently on 2 different rifles. Primers(winchester large rifle) on 1 rifle and bad Remington brass in my 300WM Encore.

HWD

huntswithdogs · « **Reply #4 on:** June 12, 2006, 07:58:42 AM »

Another thing to remember also... Too small a load of powder can cause as much, if not more, problems where pressure is concerned. Smaller charges of powder don't burn from back to front as they need to. You may be experiencing flashover. This is caused by the powder leaving a lot of room in the case and when fired the powder burns outwards first instead of forward. Kind of a double bang effect! High, dangerous pressures.

This happened to me once and it split cases right in front of the belt. The recoil was pretty rough also.

HWD

dave375hh · « **Reply #5 on:** June 13, 2006, 02:49:21 AM »

Miked,

The fact that it's a custom barrel may be the cause of your problems. If the rear of the chamber is oversized it would let the case head expand excessivly which would loosen your primer pockets, without showing any other pressure signs. Measure the belt before and after firing to see if your getting excessive head expansion. The only causes of this are excessive pressure, or a belled or oversized chamber. Anything over .001 expansion at the belt is to much. When the primers fall out the casehead has to be expanding to much, you just need to find the cause. I wouldn't rule out an overload even at 3 grains under the book. There are other factors that can boost pressure quickly, tight bore, short throat, tight neck, short chamber neck are a few. A chamber cast might be of some help to find or eliminate causes.

contender hunter · « **Reply #6 on:** June 13, 2006, 01:09:31 PM »

ALSO BULLET seated out to far and engaging the lands can create a very hi pressure spike, with a otherwise mild load.