First Reloading OOps That I didn't catch at the bench

[Cactus]

I brought the case that blew out the primer down to the local gun shop today along with another that had a strange set of lines around the neck for the experts to check out. It seems that the round that blew out the primer had a very tiny crack starting in the web and that was the cause of the problem. Not a charge issue.

The owner of the shop suggested that I should run my fingernail along the webbing or get some better lighting in my work area because the crack was very small and these rounds were the 4th reload.

In the meantime I have pulled apart all of my other .303 reloads from that session (loaded 100 shot 50) and everything was fine.

The other case had 2 indented lines all around the neck just below the case mouth. (=) We were talking about it because no one had seen that before. I mentioned that when I pulled my other rounds the gas check stayed in the neck a couple times when the bullet was pulled. The thought at the table was that if the gas check separated when the round was fired that may mark the neck of the case. When I got home, I compared the width of the gas check to the space between the lines on the neck and it is a perfect match. Has anyone else had a case marked by a gas check separating from the bottom of the cast bullet?

Needless to say these cases are now in my scrap brass bucket.

Cactus

 

[jethunter]

The three loading manuals I have recommend seating a bullet immediately after charging the case. Charging the whole blockfull and seating bullets afterwards is just asking for trouble. This is especially true if your powder/case volume combination allows for a double charge.

Glad you're OK!

I absolutely do not agree. I charge all the cases with powder and then a do a visual check using a flashlight to confirm that each case has approximately the right level of powder, then I put the powder away. So there is almost no way to accidentally do a double charge.

On the other hand if you are filling each case and then immediately seating the bullet, you have an opportunity to double charge each round.

 

[R&R Rancher]

It seems that the round that blew out the primer had a very tiny crack starting in the web and that was the cause of the problem

I'm no expert, but I seem to recall reading here that there was a procedure for using o-rings when shooting the factory .303 rounds so that the initial stretch of the case occurred in the neck. This was because of chamber variations in milsurp rifles. Failure to do this would shorten the life of the brass significantly IIRC. Could someone please chime in on this?

John