Headspace

[Hogdaddy]

.308 resized and trimmed military brass.
Will a hot barrel affect headspace?
Are what appears to be powder marks around neck of fired cases normal?
Accuracy is MOA at 25yds. Rifle is Rem 7400.

Thanks

 

[rgilbert]

A hot barrel should not effect head space. The black residue on the case neck are normal.

 

[Hogdaddy]

A hot barrel should not effect head space. The black residue on the case neck are normal.

That's good news. Thought residue might be caused by change in headspace.
Thanks.

 

[scrmblr1982cj8]

I've reloaded a few thousand used NATO cases for hunting. I've not had any issues from them.

 

[rgilbert]

That's good news. Thought residue might be caused by change in headspace.
Thanks.

The main thing is to check your primers for excessive pressure. You can Google it to see examples or pick up some of Lawmans brass. lol

 

[Jhop]

A hot barrel/chamber will if anything decrease your headspace. However you'll have to be firing a belt feed full auto long enough to get the barrel glowing and drooping to make a significant change. You're more likely to have sticking cases in your chamber effecting you first. That's a big reason the military 5.56 chamber is different from a .223. It's made slightly larger to allow soldiers to continue firing when the M16/M4A1 are hot. When you start having extractration problems, it's time to let your weapon cool down.

 

[Jhop]

The black marks are normal. It's just a little burning powder getting around the neck before the brass swells up and seals the chamber. Nothing to worry about.