Expansion Ridge on Casing Head - The Firearms Forum

trutta · 02-27-2011, 03:48 PM

Howdy all,

First post here.

I recently shot (and chrono'd) some factory Hornady 95gr SST Superpreformance loads in my Ruger M77 243. I noticed an expansion ridge ringing the case just above the head. I checked some Rem Core-Lokt casings I'd shot in the past and these too have the ridge, but it is less noticeable. The primers are not "cratered"; casings are not discolored.

Is this normal? At what point might this be a sign of a dangerously hot load? I do not plan to reload these casings.

Here's a pic:

Bindernut · 02-27-2011, 04:54 PM

Once fired brass or has it been loaded before?

From your picture, it looks just like regular expansion from being fired in a slightly loose chamber. Not neccesarily dangerously loose...just on the large end of the acceptable spec range.

I've had lots of brass like that in several rifles and reloading them isn't any more of a problem than any other.

What you want to watch out for is the "shiny" ring in that area that starts to denote an upcoming case head separation. That shiny ring will be a noticeable shade brighter than the rest of the case. When I spot a case like that, I use a dental pick or a paperclip with a hook bent on the end to feel the inside of the case in the area of the shiny spot...if you can feel a little groove starting inside the case, then it's starting to separate.
This page has some good pix of what an imminent separation looks like. http://riflemansjournal.blogspot.com...parations.html

trutta · 02-27-2011, 05:43 PM

Thanks Binder,

The cases are brand new factory loads.

I tried the wire (a paper clip) and the case is smooth inside.

02-27-2011, 03:48 PM	#1
trutta Member Join Date: Feb 2011 Posts: 3	Expansion Ridge on Casing Head Howdy all, First post here. I recently shot (and chrono'd) some factory Hornady 95gr SST Superpreformance loads in my Ruger M77 243. I noticed an expansion ridge ringing the case just above the head. I checked some Rem Core-Lokt casings I'd shot in the past and these too have the ridge, but it is less noticeable. The primers are not "cratered"; casings are not discolored. Is this normal? At what point might this be a sign of a dangerously hot load? I do not plan to reload these casings. Here's a pic: --> Last edited by trutta; 02-27-2011 at 03:50 PM..

02-27-2011, 04:54 PM	#2
Bindernut Advanced Senior Member Join Date: Oct 2007 Location: ND, USA Posts: 2,453	Re: Expansion Ridge on Casing Head Once fired brass or has it been loaded before? From your picture, it looks just like regular expansion from being fired in a slightly loose chamber. Not neccesarily dangerously loose...just on the large end of the acceptable spec range. I've had lots of brass like that in several rifles and reloading them isn't any more of a problem than any other. What you want to watch out for is the "shiny" ring in that area that starts to denote an upcoming case head separation. That shiny ring will be a noticeable shade brighter than the rest of the case. When I spot a case like that, I use a dental pick or a paperclip with a hook bent on the end to feel the inside of the case in the area of the shiny spot...if you can feel a little groove starting inside the case, then it's starting to separate. This page has some good pix of what an imminent separation looks like. http://riflemansjournal.blogspot.com...parations.html Last edited by Bindernut; 02-27-2011 at 04:56 PM..

02-27-2011, 05:43 PM	#3
trutta Member Join Date: Feb 2011 Posts: 3	Re: Expansion Ridge on Casing Head Thanks Binder, The cases are brand new factory loads. I tried the wire (a paper clip) and the case is smooth inside.