searching for the AR fanatics

[wildchild]

Probably the wrong site to ask but ya never know.
Built a 6mmAR turbo on a AR15 chassis and .89 cent brass is coming out with all sorts of chingas's on the web area and scratches and dents around the shoulder area its making me squirm a little !
The dents arnt so bad ad the blow out but the dings in the wed area actually have a bur that builds and is going to caouse rechambering issues.
Any ideas as what need filed or shaped to stop this?

 

[masterblaster1]

Pot a piece of felt Velcro on your brass deflector.

 

[rvn1968]

This is my favorite site,but," AR15.Com" covers a lot more AR problems.

 

[wildchild]

I can see the deflector making dents but I'm venturing to guess the locking lugs are catching the base area on return.

 

[hank rearden]

Can you post some photos of the brass so we can see the damage?

If the scratches/dings are near the shoulder and throat they are probably caused by the 2-3 o'clock lugs in the extension (Vampire Bites). Polishing them might fix this.

If its on the case mouth, its probably the shell deflector and the Velcro as mentioned above should do the trick.

On the web, Polishing the extractor and rounding off the 90 degree edges on top of your ejector will smooth out your extraction.

How is your pressure, Do you have an adjustable gas block?

 

[stool]

the gas system can be tuned and the ejector spring tuned.
the neck scratches are from the bbl extention..(lugs)...it can be polished but it is harder than rocks.

 

[hank rearden]

Here is the article on the ejector modification.

http://bulletin.accurateshooter.com/2013/08/ar-ejector-mod-for-improved-reliability-with-larger-cartridges/

And a thread on another site about polishing the extension. Same parent case as the 6mm AR turbo.

http://www.65grendel.com/forum/showthread.php?1875-Polishing-m4-feed-ramps&highlight=polishing+ramps

 

[stool]

THE STRAIGHT LINES on the neck are from EXTRACTION. dragging neck across the lugs(backwards).......tuff to smooth those out once the extension is installed.
reducing ejector spring tension can help

 

[jscandale]

Over on the national match forum, we have been through the ejector issues. I have performed this mod for the last 15 years. Here is the trick; DO NOT CUT THE EJECTOR SPRING. remove the ejector and take .030" off the face of the ejector and reinstall. This mod will allow the full force of the spring, but limits the travel of the ejector itself. It keeps the brass from slamming against the receiver or flying into the next county.
If you do it in a lathe (recommended), you'll need to use carbide, cause that ejector is harder than woodpecker teeth.

JS

 

[madderg]

instead of Velcro you can also use a small piece of one-side-sticky black foam weather stripping.

 

[wildchild]

Great info thanks.
I'll try to get pics up of the 2 side my side scratch and bur leaving marks in the web area soon.