headspace problems

[Dave Schenck]

I suspect that I have headspace problems with my 270. First thought it was the barrel but my gunsmith took a look and said headspace! He has not looked at it in his workshop yet - that will happen tomorrow. What accuracy problems can one expect with headspacing that is starting to go? I am experiencing groups as if I am shooting with a machine gun - all over the place. Is this consistent with headspace problems? What else can I expect?

[AJ Peacock]

How are you resizing your brass? Did you measure the once fired brass before and compared that measurement to the brass you have today?

AJ

[Dave Schenck]

I am full length resizing the brass - i should just be necking it but i am learning. My gunsmith is doing the measurement tomorrow. Is my Very erratic grouping consistent with headspace problems?

[elkaholic]

You should notice stretching of your brass (not many reloads) if you have excessive headspace. Look for a shiney (thinning) area right ahead of the web. It can cause groups to open up,,,,,Rich

[AJ Peacock]

Headspace problems can cause a lot of stuff, but unless you're measuring your fired brass vs. your resized brass, you could be over resizing your brass. Headspace is nothing more than the distance from the boltface to the datum point (about halfway up the shoulder) of the chamber. You can take a once fired brass and measure it, add about .001" and you'll know pretty close what your headspace is. If you are over resizing your brass and pushing their shoulders back several thousandths or even a couple hundredths, you have headspace issues that are not due to your chamber, they would be due to your sizing.

Here is a good article on headspace
Measuring Headspace

I've never had a rifle that changed it's headspace over time, not saying it couldn't happen, but I haven't personally seen it.

AJ

[Dave Schenck]

There is some evidence of this - not too sure what to look for. will post tomorrow again when i get more results.