Bullets backing out of case...thoughts?

[8x68s]

Not happening to me but I have heard of it happening. Specifically in a very full or powder crushing load. (Not recoil induced.) What is the cause? I'm wondering if powder has "spring back" capability or is it the trapped air in the cartridge case expanding as one goes into higher elevation locales? What got me thinking about this is the expansion and contraction of empty water bottles coming and going to higher elevation hunting areas.

I look forward to your opinions... thanks!

 

[SO I HUNT]

I think neck tension may part of this problem not sure

 

[Dean2]

A compressed powder load does exert pressure on the bullet. If it is compressed enough it will push the bullet out of the case, especially with a little vibration like travelling in an MTM case. You either need enough neck tension or a light crimp if making compressed loads. That or load at the range and shoot them right away.

 

[Mark37082]

I had trouble with compressed loads. Those long monos and RL23 didn't get along for me. Rechecked several after seating and sure enough, they had backed out significantly. I was running .002 neck tension.

 

[std7mag]

I had that happen to me when I was experimenting with compressed loads.
While the manual said "C=compressed" it didn't say how compressed.
QL was telling me 110%.
I tend now to look for charges 85-100%.

 

[MagnumManiac]

Compressed powder easily pushes on a bullet forcing it out of the neck.
I have had this several times, slightly compressed often shoots the best groups, but too much of a good thing can bite you in the butt.
I have to seat my 230g loads just prior to a match for this very reason in my 300WM, the bullets will move out of the case .030" overnight, so this is what I do. It would be pertinent to switch powders, but it works so well, I just can't seem to change it…

Cheers.

 

[Chadp82]

The bullets are excited. I think it's called premature ejection.

 

[FEENIX]

The bullets are excited. I think it's called premature ejection.

L L!

 

[BillLarson]

CRIMP....

 

[Hard H2O]

I had trouble with compressed loads. Those long monos and RL23 didn't get along for me. Rechecked several after seating and sure enough, they had backed out significantly. I was running .002 neck tension.

I had the same issue with .300 WSM and the TTSX bullets.