Brass/ Headspace problem

[ROVERT]

I recently decided to treat my .30-06 to some new brass. For the last couple years all of the brass I used in this rifle was once fired FC brass. I always got good life out of the brass, so I was going to buy Federal Brass. They didn't have any at the shop, so I picked up Win. brass instead.

I loaded up all 50 pieces and have fired about 10 of them. The fired brass all looks like this:

... that's not good. It doesn't show up in the pics too well, but you can actually feel the expansion ahead of the ring. I have little doubt that there would be failures upon another firing.

I did an amateur headspace check with tape on both a load using the new brass and a Fed. factory load. Both showed a fair amount of resistance at 4.5-5 thousandths and a lot of resistance at 10 thous... I'm pretty sure it was compressing the tape at 10 thous. This doesn't really seem like excessive headspace to me. Especially since I've never had problems before.

Velocities over the chrono are the same as with previous loads using FC brass. No flattened primers or sticky bolt.

I pulled the bullets on a half dozen rounds, ran a .338 expander through the brass, and then partial resized to create a very tight fit. I then reloaded the brass. I'm not sure if it will work, but I thought it was worth a try.

If any one has any thoughts on this, I'd love hear what your take is.

 

[cloverleaf]

Rovert,
If you have a problem there then so do I. There are much more knowledgeable reloaders here than myself..... so maybe Im wrong. But Ive got brass that looked like this 3-4 reloads ago. CL

 

[Guest]

What I believe you're seeing is a slightly out of round chamber, and the brass conforming to it. Does the ridge disappear when you resize? If so, I'd be inclined to shoot the brass and inspect it several more times.

 

[DrMike]

Trevor,

Bend the tip of a straightened paper clip. Run it along the inside of the case near the web. If there is incipient separation, you will feel it. I believe dubyam has nailed the diagnosis of what you are seeing.

 

[SJB358]

Trevor,

Bend the tip of a straightened paper clip. Run it along the inside of the case near the web. If there is incipient separation, you will feel it. I believe dubyam has nailed the diagnosis of what you are seeing.

I agree with Mike, check it with a paper clip for separation, but unless you are full length sizing those cases back to minimum specs everytime you fire them, I suspect you have a slightly larger chamber. I really don't see the issue with it at all. I have a few that do the same thing. Again, just bump that shoulder back a few thousandths... If you full length size them a bunch and really push that shoulder back alot, you will get failure much faster. The brass is going to flow forward in order to fill the chamber out again. If you just nudge the shoulders back a little, your brass isn't getting worked or expanded a bunch.

Again, check out the Hornady comparator gauge inserts or the Larry Willis Gauge. They are a very good tool for measuring your headspace and really setting up your sizing die for optimum case life. Once you get that die set up for that rifle, you will see how little you really have to trim and how long your brass will last. I say all that to tell you when the light clicked on for me, it REALLY came on and I saw the effect of not working the brass as hard and really extending brass life. You will be amazed when you see how much a FL size actually pushes the shoulder back compared to just barely bumping them. I don't neck size anything, but partial FL size everytime and I can't see any negatives to it, at all. Scotty

 

[jimbires]

Trevor , to add to Scottys post . usually new brass has not fully expanded on the first fire , or it is elastic enough that it contracts a bunch . I will neck size only,a time or two until I feel the bolt getting stiff while closing the action . then you can measure full expanded brass and push the shoulder back about .002 . sizing this way will definitely add to brass life , and it will chamber just fine . Jim

 

[ROVERT]

Thanks guys, I believe you are correct. I checked the inside of the case and it appears to be fine. When I first saw the cases, I just instantly assumed it was a head space issue.

I've reloaded far more for this rifle than any other and have never seen such noticeable expansion before. Is it possible that a difference in composition of the FC and the Win. brass is the reason?

Scotty and Jim:

I only partial full length resize for all of my bolt rifles. I know well what you are talking about in terms of the elasticity of new cases. I set up my dies for a very slight crush fit (since I haven't invested in any head space measuring equipment yet) and it usually takes two or three firings on new brass to be able to feel the resistance.

Thanks again guys, I'll try reloading some of the brass and let you know how it goes.

 

[Guest]

If you have a mic, check the nominal case diameter at the webbing. I'm betting this batch of brass is just at the small end of spec, or perhaps a tad under spec.

 

[ROVERT]

If you have a mic, check the nominal case diameter at the webbing. I'm betting this batch of brass is just at the small end of spec, or perhaps a tad under spec.

A mic is another tool on my to buy list. My calipers show the new (unfired) brass to be .463". The fired brass is at .472". I know calipers aren't considered accurate enough for these measurements, but that is what I have on hand.

According to what I could find, the brass is probably close to min. spec (.4698", -.008" tol.) and my chamber is probably close to max spec (.4708", +.002" tol.).

 

[Guest]

Sounds like you're on the money with your assessment of brass and chamber specs. By the way, my mentality is safety first, and you (IMO) did the right thing with this by noticing and questioning it. Not that you need me to approve of how you load and shoot.

 

[BK]

Larry Willis Gauge.

Thanks for posting this, buddy. I was going to order the gauge and the belted mag collet die, but I let it slide long enough that I forgot the guy's name. Oops. Bookmarked now!

 

[SJB358]

Kurt, I don't think you would ever need the belted magnum collet deal, but the digital headspace gauge is excellent! Scotty