headstamp disturbance

Talk about the AR15 style rifles chambered in 450 Bushmaster.

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Re: headstamp disturbance

Postby tbirdman74 » Fri Feb 03, 2012 4:04 pm

Well, was successful at cleaning up the sharp edge around ejector hole, and less than successful with pictures. Have them, figuring out how to post them is another story. Soon as I got it figgered out they'll be here.
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Re: headstamp disturbance

Postby 9x19MdM » Fri Feb 03, 2012 4:15 pm

tbirdman74 wrote:Well, was successful at cleaning up the sharp edge around ejector hole, and less than successful with pictures. Have them, figuring out how to post them is another story. Soon as I got it figgered out they'll be here.


www.photobucket.com is the easiest way. It's free, you select the pic's you want to upload, and away they go. Then when you want to post one to the forum, just select the link code and copy it to the post.
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Re: headstamp disturbance

Postby tbirdman74 » Fri Feb 03, 2012 5:31 pm

Image
Before
Image
After

Pics ain't that great, still haven't dug out good camera.
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Re: headstamp disturbance

Postby wildcatter » Fri Feb 03, 2012 6:15 pm

tbirdman74 wrote:Yep, one big burr all the way around the ejector hole. Looks like they drilled it with a hatchet. Time to tear it down and clean it up.


Well, there ya go then.

Just make sure you adhere to Hoots admonitions. For you other new guys, clean the factory lube(s) off the weapon (inside/out), re-lube the action properly, absolutely make sure the chamber is bone dry, and that no oils can migrate into the bore (This is all true of any weapon you buy, new or used. To do otherwise, risks, broken parts or worse.)..

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Re: headstamp disturbance

Postby Hoot » Fri Feb 03, 2012 7:25 pm

I gotta say, What happened to the Bushmaster I used to know? No way that bolt got checked before it shipped. Hell, they didn't even check the test round (assumed) case head of they would have seen the swipe. It breaks my heart to see that happen to a company. :cry: My LAR-8 faintly swiped case heads when I got it, but in RRA's defense, you could not see the burr, even under my stereo microscope, until I lapped the face with 600 compound and only then the difference in parkerizing wear gave it away. Certainly not as obvious as Tbird's but it taught me that it doesn't take much to visibly swipe brass.

All these new faces and the pleasure of watching them building their self confidence and competence. Sorry if I sound sappy, but it's rewarding on several levels to be part of this group.

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Re: headstamp disturbance

Postby 9x19MdM » Fri Feb 03, 2012 7:33 pm

I'm not seeing what the issue is. What am I missing?


Image
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Re: headstamp disturbance

Postby tbirdman74 » Fri Feb 03, 2012 7:36 pm

The outside edge of the small countersink around the ejector hole had a burr most of the way around it. Probably 3-5 thou. Made distinct impression and swipe on case head.
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Re: headstamp disturbance

Postby Hoot » Fri Feb 03, 2012 9:48 pm

tbirdman74 wrote:The outside edge of the small countersink around the ejector hole had a burr most of the way around it. Probably 3-5 thou. Made distinct impression and swipe on case head.


The raised area defined by the two red rings should not be there. The perimeter of the hole should be flush with the face.

Image

This is usually caused by the drill bit feeding too fast into the metal and actually displacing metal instead of cutting it off.

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Re: headstamp disturbance

Postby tbirdman74 » Sat Feb 04, 2012 10:59 am

OK, little misunderstanding, my bad. Thanks, Hoot, for the red rings on my pic, this will help me to explain. Inner ring is ejector hole, between rings is countersunk I'm guessing maybe 20 to 30 thousanths. Outside of outer ring was where the burr was, and if you look at the three o'clock position of the outer ring you will see a bigger ding of unknown origin. Hope this clears it up.
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Re: headstamp disturbance

Postby Hoot » Sat Feb 04, 2012 11:22 am

That is too funny and a testimony to the value of both 3-D images and careful reading techniques. I thought that picture was the before and showed a ridge all the way around the hole of biblical proportions. Think mega burr. Now I see it was misinterpreted shadows. It just hit me that I'm seeing negative height. IE inside chamfer.
Image

M C Escher is laughing at me from the grave. ;)

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