Brass ejector marks (UPDATED)

[wvchevy3]

While breaking in the barrel on my new .308 tikka I noticed extractor marks on my brass. The Lapua on the left is handloaded with a start load , on the right is factory Remington. Both show extractor marks, both cases measured 3.614 unfired and 3.616 fired using a head and shoulders gauge. Bolt lift was slightly tight upon extraction. Any ideas , I was wondering if its possibly a tight chamber. Lee

 

[gerry]

If it was just one brand of brass I would suspect soft brass but with two it would be very unlikely. I would also be guessing a tight chamber or bore would be the culprit, it will be interesting to see what others think.

 

[DrMike]

As Gerry stated, I would be inclined toward suggesting the chamber is a tad tight. Without other evidence of pressure excess, I wouldn't be overly concerned about the extractor marks on this load.

 

[wvchevy3]

That's my thoughts exactly, I was thinking tight chamber as well. everything else looks good ,I threw in there a factory loaded round with a different headstamp to see if it was the same. I just hate seeing those ejector marks on my brass .Lee

 

[Ridgerunner665]

I sound like a broken record, I know....but...oily chamber?

 

[gerry]

Good point I have seen that after cleaning before too.

 

[wvchevy3]

Now that's possible.. it is a new rifle, I cleaned it well before i started , but I will check it out again.Lee

 

[wvchevy3]

but would an oily chamber give you a slightly hard bolt lift? Lee

 

[gerry]

Absolutely, excess bore cleaner has done that for me. Find a way to make sure it's clean and maybe the problem will go away. Would be an easy thing to fix.

 

[wvchevy3]

I will check it tomorrow.Lee

 

[Ridgerunner665]

Mop out the chamber....and make sure there is no sizing lube on your brass.

I dump my brass into a bowl of acetone after sizing...don't do that with loaded ammo.

 

[wvchevy3]

Brass has not been resized, New Lapua brass. The loaded factory ammo has none either. I will check and mop out chamber tomorrow.Lee

 

[Guy Miner]

I sound like a broken record, I know....but...oily chamber?

That would be my first guess.

 

[Guy Miner]

First guess isn't necessarily right, but you've got to admit it would require but a simple solution! :grin:

 

[Ridgerunner665]

Gotta love a simple solution....just wish they were all that was required more often!

I hope this turns out to be the case here...it was for me a few years back, and took me a good while to figure out what it was.

 

[wvchevy3]

I hope it is too.... Lee

 

[Ridge_Runner]

If your using a slower burn rate powder up your charge to mid level, under pressure gives the same signs as overpressure
RR

 

[wvchevy3]

I wanted to get some of my new lapua cases fired to get an H2o capacity. I was using Tac so it wasn't slow burning. load was 47 gr.gm210 and 125gr bt

 

[wvchevy3]

Nosler #7 has a start load of 46 gr Tac.Lee

 

[wvchevy3]

I sound like a broken record, I know....but...oily chamber?

You hit the nail on the head....... with your advice and the help of some denatured alcohol I mopped out the chamber, Problem solved. Thanks for a simple and quick fix, I can see how this could have made me scratch my head well into next year. Lee