.270 brass potential problem


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tcanthonyii
December 23, 2012, 04:50 PM
I started cleaning about 180 rounds of 270 brass I've saved up. When pulling them out of the tumbler I noticed that a large number of them had an odditie in them. Counting them up most of them didn't have it. This makes sense as I sold 1 270 and bought another right before hunting season. Sure enough upon firing my Marlin XL7 yesterday with 3 rounds they looked like this:
http://i1088.photobucket.com/albums/i321/tcanthonyii/th_IMG_0755.jpg (http://s1088.photobucket.com/albums/i321/tcanthonyii/?action=view&current=IMG_0755.jpg)
Click on the pic to make it bigger. I wanted to leave these as big as possible.

All my other casings not from this firearm look like this:
http://i1088.photobucket.com/albums/i321/tcanthonyii/th_IMG_0756.jpg (http://s1088.photobucket.com/albums/i321/tcanthonyii/?action=view&current=IMG_0756.jpg)

Obviously I have a problem with the gun. This will be addressed with Marlin. However are the casing still usable for reload? My guess is no. What the pictures dont show well is that some of the casing look like it's a crack more than a wall defect but nearly all casing look identical and you can clearly see when one is in hand tooling marks.

If they are unusable I'll save them back, drill a hole in them or drill the primer pocket out and use them for bullet length gauges or tchotchke type projects.

Thanks

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ReloaderFred
December 23, 2012, 05:20 PM
The shoulders were set back too far when the cases were sized, making a headspace problem for this rifle. The brass stretches upon firing and the brass has to come from someplace, so it comes from where the case wall meets the thickening of the base. Those cases are beyond use, but you can use them to set your sizing die properly for this rifle.

Your new rifle has a chamber that is longer than the last one, but probably still within specifications. It can be checked with headspace gauges.

Hope this helps.

Fred

tcanthonyii
December 23, 2012, 05:21 PM
Actually. Forgot to mention those are factory brass. Not reloads. Different lots of ammo as well. Headspacing had crossed my mind as well. At least it's easy to correct on an xl7.

rcmodel
December 23, 2012, 05:27 PM
Definitely incipient case head separation for whatever reason.

If you bend a feeler out of a paper clip or wire with an L on the end, you can reach down inside the case and feel the stretch rings on the inside.

rc

tcanthonyii
December 23, 2012, 05:29 PM
Well then reloading may have saved my hands then. I've got over 80 rounds through this thing and never noticed a problem until I started reloading. Definately going to make me pay more attention.

kingmt
December 23, 2012, 07:52 PM
I can't tell if it is starchEd or just tiling marks in the chamber. Check as RC said.

rcmodel
December 23, 2012, 08:09 PM
I can't tell 100% either.

But it is in exacty the right place for a case head seperation.

rc

murf
December 23, 2012, 09:46 PM
looks like a wire brush bristle imbeded in your brass. suggest you clean your chamber, first.

murf

tcanthonyii
January 1, 2013, 10:14 PM
OK so here's what I did. I didn't know what exactly is head space. I always thought it had something to do with OAL. Looked up the explanation and it's the length from where the shoulder stops to the back of the case. OK. Makes more sense to me now. WAY more sense. OK so I took 3 casings. 1 new never fired Federal. To obtain this I sacrificed a new round using my bullet puller. A casing that had been shot from my old 710 270. And 1 from my Marlin.

I took the Once fired 710 casing and the bolt closed very easily on the Marlin, like an unfired round. I then took a once fired casing from my Marlin and closed the bolt. There was a noticeable difference in pressure closing the bolt. I think I've confirmed the headspacing issue.

I took this a step further and measured the casings. The new casing Measures 2.530. The 710 casing, once fired is 2.535. The Marlin measures 2.541!! That's a 6 thousands difference. Quite a bit. And 11 thousands more than a stock casing. I took a sample of 10 once fired from my old 710 and 10 once fired from my Marlin and they were all similar. To me this would equate excessive headspace.

I'll attempt to call Marlin tomorrow. However since I'm not the original owner and the gun is exactly 5 years old I'm not sure they will do anything. If not I'll just have to attempt to find a smith locally as I’m not equipped to do the work myself.

Thanks for the help!

kelbro
January 2, 2013, 10:13 AM
How/where did you measure the cases? The total length? If so, that will not tell you about headspace.

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