204 head seperation

[jacob.elliott]

I don't know exactly where to put this post but here goes..

last weekend a friend and I were shooting he was shooting his new england in 204 ruger. one of his cases seperated and it looked like someone had just taken a tubing cutter and cut the case in two.

It was the third time the case had been loaded and was well under the max load according to the manual. and there were no signs of high pressures (on the Primer)

It was hornady brass. I have brass that has been loaded 5-6 times in my 17-222 and have never experienced head seperatoin only neck splits. do you think it might have just been a weak case because no other rounds seperated?

 

[rcmodel]

I think he is probably resizing his cases too much, pushing the shoulder back too far, and creating artificial excess headspace.

The case stretches to fill the chamber each time he fires it, and by the third firing, it has stretched to the breaking point.

If he took an L-bent wire or paper-clip and reached down inside the case, he could feel the stretch ring where the case is eventually going to break.

Have him back off the sizing die until sized cases will barely close in the action and the problem should go away.

rc

 

[243winxb]

Sizer die setting for minimum headspace

When the shoulder is pushed back to far on FLRS this can happen. The case stretches to fill the chamber. Brass can come apart at the head or in the middle of the body. To correct your Cartridge Headspacing , look here. http://www.brownells.com/aspx/NS/GunTech/NewsletterArchive.aspx?p=0&t=1&i=1305&mc_ID=2019 RCmodel found this link, its a good one. Look for a shiny ring like in this photo, it will go around part or all of the case body below the web or in the middle of the body. This case would have come apart on the next firing.

 

[fguffey]

Again, the case BODY locks onto the chamber, from there if the case stretches, where are the skid marks? Behind the body of the case is the web, if the firing pin drives the case forward and if the case locks onto the the chamber, the only place the case can stretch is between the web and body. Get a machinist feeler gage with instructions, adjust the gap between the bottom of the die and top of the shell holder to compensate for that little bit of stretch that is caused by firing and compression when sizing, reducing all that travel adds to case longevity.



F. Guffey