Community
Reloading Share techniques for reloading, where to get the hottest in reloading equipment and learn how to reload from fellow hunters.

Case Head Expansion

Thread Tools
 
Old 12-21-2009 | 07:43 AM
  #1  
bigcountry
Guest
 
Posts: n/a
Default Case Head Expansion

Anybody still measure case head expansion as a way of seeing pressures?

I have came to the conclusion that its not worth it. I think the only way it can be done is to measure a "new" case before and after firing and seeing the change.

I use a set of starrett mics.

I did a test this weekend, where I was building up a load for my STW. I took the load up in 0.5increments until I felt heavy bolt lift. The cases were new winchester cases. For the most part, I seen 0.0005" case head expansion with the "heavy bolt lift" cases. With the others, for the most part, I seen only 0.0003" or less. So I feel the theory is sound. But several cases did not coorelate the mic measurements and pressure signs.
 
Reply
Old 12-21-2009 | 08:46 AM
  #2  
driftrider's Avatar
Nontypical Buck
 
Joined: Feb 2003
Posts: 3,802
Likes: 0
From: Coralville, IA. USA
Default

It's probably a legitimate method. I don't use it because I only have a digital caliper that isn't precise enough to measure ten thousandths accurately. I look for the typical early pressure signs, harder than normal bolt lift and flattened primers. If I see either, I'll back down to the most accurate load below that that didn't show pressure signs.

Mike
driftrider is offline  
Reply
Old 12-21-2009 | 10:09 AM
  #3  
bigcountry
Guest
 
Posts: n/a
Default

I have a set of starrett anvil mics. Plus blade mitotoyos calibers. I don't really trust the calibers down to .0001. So only place to measure with the starretts is the rim itself. Or the belt.

Here's my thing. I bet it depends alot on brass brand too. In other words, if you had a pressure strain gauge. And lets say for both pieces of brass, you are reaching 70KPSI. But the webbing of brass A is stiffer. Brass B might show greater than .0005" expansion.

Just thinking outloud.
 
Reply
Old 12-21-2009 | 04:10 PM
  #4  
Nontypical Buck
 
Joined: Jan 2004
Posts: 2,925
Likes: 0
From: Baileysville, WV
Default

Ken Waters sure did like that method BC. What little I have reloaded I have measured it a little too. My calipers really arent good enough to do it seriously.
Doe Dumper is offline  
Reply
Old 12-21-2009 | 04:57 PM
  #5  
bigcountry
Guest
 
Posts: n/a
Default

Thats what I was kinda thinking. Just heading into "shooting" season and was playing around a bit. 58th load? Thats just crazy. Surprised he didn't get a cracked neck at least. But his thoat is probably so tight it probably doesn't work it at all.
 
Reply
Old 12-22-2009 | 04:49 AM
  #6  
Nontypical Buck
 
Joined: Aug 2004
Posts: 3,329
Likes: 0
From: Michigan
Default

Originally Posted by Ridge Runner
Big,

noslers lose the pocket the first firing. RR
That sucks. I bought a bunch of this brass in .308 and .30-06. Oh well. You're not the only one I've heard this from. There are at least two others that have told me Nosler Custom brass isn't all that great.

Tom
statjunk is offline  
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off



Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service -

Copyright © 2026 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.