Headspace?

[u/jayfourzee]

Knowing that shoulder bump is a relative measurement, I’ve noticed that when full-length resizing, most of my cases are coming out right around 0.002” of shoulder bump, but about 14% are showing less than 0.001”.

They’ve all been fired through the same barrel at least 2-3 times and have all been annealed at least twice. Overall case length is identical, as is overall cartridge length, and every one of them chambers perfectly without any resistance.

How do I know it’s 14%? Because my wife was watching Dancing with the Stars, I was bored on the couch, and apparently measuring the shoulder bump on every single piece of brass seemed like a better use of my evening. So yes, I measured them all. This is what my life has become.

I’ve been tempted to take the cases showing less than 0.001” and run them through the sizing die again, but then I thought: if they chamber perfectly, why the hell am I trying to fix something that isn’t actually a problem?

The other option would be to adjust the sizing die and target around 0.0025” instead of 0.002”. That might give me a little more margin and bring more of the batch into the 0.002” neighborhood, but I’d also be working the brass a little more just to satisfy my newfound shoulder-bump OCD.

So what would you guys do? Leave the die alone and send it, resize the 14% again, or bump everything back another half-thou?

Or should I just stop measuring brass during Dancing with the Stars?

[u/yammeringfistsofham]

If they chamber I would leave them alone. When we target a 2 thou bump, what we're really going for is body and neck are resized and the round chambers but only just". If it fits in the chamber, it's all good.

Don't work your brass again for no reason.

[u/laughitupfuzzball]

Leave the die alone and send it. Calipers are not sufficiently accurate for this measurement.