Dangerous situation and don't know why?

[Milt1]

I'm not sure that I buy into the "bullet jump" theory because 16 grains of 2400 fills up 3/4 or better of the case. In order for the pressure to be "that" reduced the bullet would have to be very loose in the case (imo) and I didn't experience any difficulty in cocking the revolver so I don't think there was sufficient movement of the bullet which would have hindered cocking. Rather I think the primer was insufficent in setting off the whole charge but enough to send the bullet into the throat and make quite a bit of the powder gummy.

 

[243winxb]

neck tension-bullet pull

When the primer fires, the bullet may move to soon.

Too Much Primer
You can have too much primer. When the output gas volume of the primer approaches that of the cartridge case, sometimes special handling is required. I remember when CCI was working with some experimental primers for 9mm Luger, and we started seeing odd time-pressure curves on the computer. Instead of the normal single peak, we saw two.

It was a classic case of high gas volume but too little temperature. The primer’s extra gas unseated the bullet while still trying to light off the main charge, producing one peak. Then the bullet retarded as it engaged the rifling, creating the second peak. Although a shooter would never notice this in a production firearm, that double hump was worrisome, and we abandoned that mix.

http://www.shootingtimes.com/ammo/ammunition_st_mamotaip_200909/ When using slow burn rates of powder, the above also happens in magnum rifles when using light bullets for the cartridge. There is not alway a "second peak". Without pressure, powder stops burning.

 

[Milt1]

I read the primer article and it seems to be a complex issue and interesting reading. Alliant proposed the use of small pistol primers when using their 2400 powder and I was using Winchester small pistol primers. As I've stated earlier, I think the problem is connected to the primer but we'll never know for sure.

 

[Salmoneye]

Low pressure not igniting large amounts of powder is well known with some powders such as H110/W296...This can be caused by not enough crimp, or primer not being hot enough, etc....

The result is a lodged bullet and a glob of fused powder (for lack of a better term)...

This sounds exactly the same...