barrel length vs gas block location vs port size
 

I am trying to get a 6x223 running. I know it isn't a 300W but everyone was so much help on my whisper project, I thought I would check in here for answers.
My upper consists of an 18" barrel with the gas block in the carbine position with a .067" port. The caliber is 6x223 or 6x45. I am having problems with the fired cases ejecting. The extractor is jumping over the rim and the bolt is picking up the next case and jamming against the back of the fired case that is in the chamber. I am trying H335 with an 85G SGK. The loads varied from start load to max load(Lee Reloading Manual). All loads had the same issues. I did get a few out of about 15 rounds to eject and pick up the next round properly. The fired cases ejected easily (some of the max loads were a little sticky). The velocity is a little lower than the book values for the min and max loads.
When I chambered the barrel and was playing around with dummy rounds with the ejector removed the extractor seemed easy to snap over the case. Yesterday I compared to another bolt and the other bolt is a little harder to snap over the rim of a case in the chamber.
When I loaded these rounds I worked with the shoulder to rim lenght to minimize headspace. The rounds would chamber out of the mag no problem.
Everything works fine manually.
Where do I go from here? should I have gone with the rifle length port location even though I wanted the block under the handguard? Is my port too large? Is my extractor bad? Is my extractor spring bad? Is my rim to datum case length too long?
Chip

First you want fresh extractor parts:
spring, insert, and o-ring.

Like so:
http://www.bravocompanyusa.com/BCM-E...%20upgrade.htm
You can get them lots of places, but those are the parts you want.

The extractor itself may need replacing too, if its warn, and not getting enough bite.

Start with those parts and see how you do. Clean and polish the chamber too. What brass are you using? Some brass is stickier than others. What does the brass look like? Ripped of rim where extractor was? When my 300 loads get too hot, I get cases stuck in the chamber, but the extractor rips its part of the rim off. Thats pistol port too. Carbine on an 18" should be fine. Not sure about the 0.067... not that familiar with the numbers.

The brass I am using is Speer 07. It has a military crimp and it was real consistent in weight. The rim isn't ripping off but it is leaving a burr when it jumps over it. You can see where a little of the metal is gone on the inside of the rim. It is a new chamber and I think it would benefit from polishing and cleaning. I will try the extractor kit. Does it come with the extractor? Are all extractors the same?

Is this a new bolt and extractor, or did it come from a previously used rifle? Having the extractor come of makes it sound like it or it's springs are worn. I would say it isn't just an issue of gas port location as the carrier is moving enough to feed a new round. It could be that the bolt is unlocking while there is still too much pressure, what weight buffer are you using? You might try a heavier one if possible to try to keep the bolt locked in place a little longer.

Whats your load? Ill pop it in quickload to see approx what pressures your running.

Also whose reamer did you use for the chamber?

Mike

re
 

"Is this a new bolt and extractor, or did it come from a previously used rifle? Having the extractor come of makes it sound like it or it's springs are worn. I would say it isn't just an issue of gas port location as the carrier is moving enough to feed a new round. It could be that the bolt is unlocking while there is still too much pressure, what weight buffer are you using? You might try a heavier one if possible to try to keep the bolt locked in place a little longer."

All the parts on the upper are new. Most of it is dpms, I think the bolt and carrier group is bushmaster. My buffer is the standard carbine buffer. It does seem that the bolt is unlocking while the case is under too much pressure or the extractor isn't grabbing well. It does work when I manually cycle the action after a jam and the case is still in the chamber. Would a pigtail type gas tube or a fatboy gas tube change anything?

"Whats your load? Ill pop it in quickload to see approx what pressures your running. "

From memory it is a starting load of h335 - 23.5G and a max load of 25.5G. The bullet is a SGK 85G. The oal is max mag. 2.262" Other than OAL I pulled it out of the Lee manual. Maybe the oal is driving the pressure up. I had problems with the starting load doing the same thing. The primer on the starting load looked fine. the max load was a flat.

"Also whose reamer did you use for the chamber?"

The reamer is a PTG.

Thanks Chip

The pigtail gas tube could help to delay the ejection a little, though I don't have any experience with those. You an also try an H or H2 buffer to delay the carrier a little bit.

Maybe I missed it, but did you ever mention if you were checking velocity on these loads? If you know velocity numbers that can also show a little more info, especially when checked against the quickload predictions.

The book values start load - 23.5G - 2587 fps and max load - 25.5G - 2818 fps. The oal in the manual is 2.350". My chronograph was messing up and I got one reading at the 24.5G load and the velocity was 2649 fps. That seemed to fall fairly close to the expected. My oal is shorter and I would imagine my 18" barrel is shorter than the Lees test gun.
Thanks Chip

I say confirm the extractor parts, if its a new bolt, then the spring and insert should be ok, but an o-ring could help. The o-ring is standard hardware store stuff, 1/4" outside diam, 1/8" inside diam. Slip it over the extractor spring.

Polishing the chamber will help too.

If the whole thing is new, then it probably needs a few rounds to knock the park off the parts. And make sure its WET with oil.

What parts should be wet? bolt and barrel extension?