extractor polishing pictures??

[Redraider]

Hi all,

I have seen these pictures here several times before, now that I need them I can't find them..............can someone point me in the right direction for locating these pictures, or the process itself?

Thanks

Redraider

[rg1]

Here's a very good tip for increasing feeding reliability by doing some mods on the ejector pin:http://bulletin.accurateshooter.com/?s=6...mit=Search

[LRRPF52]

Extractor or ejector?

Here are just some aspects of it. There is a great thread on the old Sniper's Hide, that has been copied and pasted with the pics to other forums done by a 30yr armorer and competitive shooter/AR15 and AR10 smith who worked out a lot of tweaks to make the guns feed better, and treat brass nicely.




There are several interface points of the extractor that can be enhanced to get rid of rim damage, and unwanted pinching of the case rim leading to sluggish or arrested ejection.

You are going to need some tools, an IQ that is higher than normal nowadays, mechanical comprehension, and patience. I dealt with this issue on a friend's .243 LBC AR15 just the other night, because a DPMS 7.62x39 bolt had been used for the chambering and headspacing. There isn't a lot of room to work with on a 7.62x39 bolt with a .125" bolt face depth, as the extractor lip is now limited in what can be removed to allow articulation of the thicker Grendel rim as it feeds and extracts in and out of the AR15 bolt face.

He was getting erratic ejection and failure to eject rechambering of spent cases and stovepipe malfunctions. He had a typical sharp extractor with the fangs on the ends, so I carefully tuned it. I also took some measurements of the extractor, and compared it with several 6.5 Grendel bolts and their extractors, taking note of the groove length/depth and lip thickness dimensions, which were considerably different, and inferior on the DPMS 7.62x39 bolt with .125" face depth.

With your bolt disassembled, you will also want to radius your ejector to eliminate right side feed lip presentation malfunctions that are common with sharp ejectors. You can see that this has also been performed in the above photo. I like to re-phosphate the polished surfaces now, to reduce the potential of oxidizing.

Here's an example of a 5.56 bolt without the radius:




And a Grendel bolt with it:



Another area that can create a lot of brass shear and shavings is the leading edge of the extractor pocket and bolt face. It helps to knock this edge off slightly so there is no longer a sharp 90* angle, then buff it with a small cotton wheel and buffing compound. If you are not comfortable making changes to your bolt, seek help from a competent AR15 smith.

[65Whelen]

Great info, thanks LR.

[rg1]

Here's another thread with some extractor pics: http://blackholeweaponry.proboards.com/t...ion-issues
Can't find the thread showing some step by step polishing that I too have seen. Doing the ejector pin modification helped my Grendel more than anything. Polishing the extractor only helped to keep cut marks in the rim of my cases but I think it also helped keep brass shavings out of the action.

[LRRPF52]

That's a great example of a tuned extractor, when looking at removing the offending corners of the lip:

[Redraider]

Thanks guys, that is what I needed.

Redraider

[jawbone]

great pics and trustworthy info. many thanks, LRRP.