Case head expansion

1

17remhunter

Active member
Case head expansion is a sign of pressure but does that mean you can still use the case or not. The expansion was .003. Primer pockets were still tight
 
Last edited:
I've never measured case head expansion. I've used other pressure signs from what I've learned , right or wrong. If brass holds a primer , I shoot it. If after a few firings I get a little leakage around the primer , I scrap that batch. I use a few pieces for test before loading a whole batch . I run my 17-204 pretty hard, have enough brass and bullets to ruin the barrel.
If you are worrying about brass life back off the gas a little.
 
Last edited:
If you are seeing .003 or even .002" it's too hot. Unless you're on the Marine team on the 600 yd line at Perry, then it sounds about right. Nobody picks that brass up!
 
My pressure issues were when I was using CFE 223. Im my 17 Remington. Once I was shooting in 75 degree weather and my cartridge got warm. Hodgdon said to switch powder and go to H4895 CFE 223 was very Temperature sensitive. My other issues with pressure was in using Nosler brass. The jury is still out on the Nosler brass from me experience with it I question Noslers integrity
 
Measuring case head expansion is extremely difficult, for multiple reasons. Tool accuracy/repeatability. Just remeasuring the exact same location/axis is hard. Even the chamber may not be perfectly round(likely isn't). And an individual case(s) may have manufacturing issues with uniformity in materials(brass material lots) as a result of mixing on production lines. Use multiple data sources for load development, know that at any time either low or high charge weights may cause safety issues and that powder lots vary in burn rates/energetics.
 
spotstalkshoot said:
Measuring case head expansion is extremely difficult, for multiple reasons. Tool accuracy/repeatability. Just remeasuring the exact same location/axis is hard. Even the chamber may not be perfectly round(likely isn't). And an individual case(s) may have manufacturing issues with uniformity in materials(brass material lots) as a result of mixing on production lines. Use multiple data sources for load development, know that at any time either low or high charge weights may cause safety issues and that powder lots vary in burn rates/energetics.
Click to expand...
Some of the same thoughts I have had , but didn't post. Figured someone would chime in with more time at the bench ,than I.
Pretty much why I don't measure case head . Based on what I had read in the past, I wasn't going down that rabbit hole.

Good info
 
Last edited:
17remhunter said:
My pressure issues were when I was using CFE 223. Im my 17 Remington. Once I was shooting in 75 degree weather and my cartridge got warm. Hodgdon said to switch powder and go to H4895 CFE 223 was very Temperature sensitive. My other issues with pressure was in using Nosler brass. The jury is still out on the Nosler brass from me experience with it I question Noslers integrity
Click to expand...
I haven't looked at 17 rem data in a long time, so I don't know what's popular or best. Since my 17-204 is a custom chamber , I used powders based on what my smith had tried.

Being I grew up a woodchuck hunter , I always did my load work in the heat of the summer. Do all my rifles this way no matter the use.

Hopefully you find something that works good and you can find it easily and not take out a loan to buy enough. Prices these days make me ill.
 
Last edited:
Back
Top