Well, I finally managed to take my 9mm SBR build out to the range today to see if the latest tweaks I made helped any.  I'm glad to report that the bolt hold open now works so that's one demon foiled.  The fix ended up being the bolt catch had too much metal at the bottom tip where it contacted the side of the lower.  When the empty magazine follower attempted to engage the bolt catch, not enough of it was touching the bolt to keep it open.  I've got a theory why I had to make this modification, and I'll get into that later.

Unfortunately, the remaining demon is still there.  It's failing to eject reliably and here's where you guys can help.  For those that have working setups, does the ejector ride close or even touch the bolt face?  There's a good gap between the bolt face and the ejector on mine.  The other evidence I had was upon one malfunction, there was a spent case that was sitting on top of the hammer.  The only way a case could get there is if the ejector completely missed the case and the bolt pulled it past the bolt catch to drop it on top of the hammer.

The fix for the ejector issue would be to bend the ejector to touch the bolt.  I've got a question before I do anything fancy with a pair of pliers.  Are RRA dimensions of the upper and/or bolt carrier group fundamentally different enough from a Colt to cause both?  Another poster raised a good question about whether or not they are dimensionally the same, and it seems to me that the RRA parts tend to place the bolt higher.  Would a different brand of upper and/or bolt group be a better match for the mag block?  I don't want this to turn into a brand bashing thread please, I just want to get my build to work before I lose all faith in 9mm and switch to a fire-breathing 5.56mm cannon (not dissing those either, I might build one anyway).

For reference, my build uses a complete RRA 9mm upper mated to a DPMS lower with a Hahn dedicated block.

Quoted: .  For those that have working setups, does the ejector ride close or even touch the bolt face?  There's a good gap between the bolt face and the ejector on mine.    The only way a case could get there is if the ejector completely missed the case and the bolt pulled it past the bolt catch to drop it on top of the hammer. HEHEHEHEHEEE !! You just answered your own question, you found where it is important to have all the ejector tap you can get -- In the pics you can plainly see where the case has marked the bolt face and ejector (follow the line around... see where it is possible to have very minimal case contact to ejector face if the ejector was adjusted away from center of bolt) .... The fix for the ejector issue would be to bend the ejector to touch the bolt.  I've got a question before I do anything fancy with a pair of pliers.  Are RRA dimensions of the upper and/or bolt carrier group fundamentally different enough from a Colt to cause both? NO, small manufacture variance between individual upper and lower can shift block position (ejector most noticable) to 1 side or other in relation to bolt travel in the upper,, this is why each 9mm rifle build needs a little sit down time and verify that all is in correct relation to each other. Another poster raised a good question about whether or not they are dimensionally the same, and it seems to me that the RRA parts tend to place the bolt higher.  Would a different brand of upper and/or bolt group be a better match for the mag block?   See above comment, manufacturer tolerances being stacked between makers individual parts.  There is only 1 drawing for the AR-15, this is what makes it so great that many people can make parts, but there will be slight variations between makers.

Thanks for the help.. that confirms my theory.  I took the mag block out to inspect the ejector and only the upper left corner of the front edge has any brass marks.  I'll see if Hahn will still warranty my mag block if I take some WECSOG to the ejector.  With my luck on the build so far, I can easily see something breaking.

Put your block back in, and adjust your ejector.  Go slowly, and you should be ok.

Mine actually sit a hair low, but it is close to center... works fine in my instance.  

You can see where COLT left minimal case contact in their design/eject placement, so you need to get all the contact you can... it is not Hahn fault, they simply build to COLT design, then toss in all the weeee imperfections of the uppers & lowers.

Your ejector is fine you are having extractor problems.  The extractor is not holding the case up against the bolt face for the ejector to get a solid hit on, leaving the case in the chamber area.  This is a common problem and usually it's the roll pin being weak and other times it is just poor tension on the claw.

The RRA upper works fine despite the occasional extractor problem.  Your identical setup runs very well for many people and has been doing so for quite some time.

I don't want to sound like a know it all, because I have only had two 9mm AR's.  One was a Colt that worked great, but like a dummy I sold it and bought a RRA.  The RRA had all sorts of problems ejecting empties and in fact I started an older thread regarding my problems.  Eventually I fixed the issue by SLOWLY working the bolt with a dummy shell in place to see what "initially" happened to the case when it contacted the ejector.  When I first did this the case would get pushed to the RIGHT side of the reciever and NOT towards the ejection port.  It was my belief that this wasn't proper as I had never seen this before on any semi-auto firearms that I have worked on or owned in the past.  Empty brass must be ejected towards the ejection port opening or it can't get out of the gun effectively if at all.  I didn't want to bend on the ejector too much, but did tweak it a little.  The real cure (for my gun) was to file an angle on the tip of the ejector that "guides" the empty case towards the ejection port.  I have put almost 600 and some rds. thru the gun now without a single malfunction.  Empties are tossed 3 to 6 feet from the gun depaending on ammo used.  The real plus is that the RRA is WAY more accurate than the Colt was and I am pleased with the results.  Hope this helps, if needed please feel free to contact me for follow-up.    Rick  

This is my experience. I originally assembled my 9mm carbine during the ban when RRA built 9mm uppers and supplied parts, but did not build a complete 9mm gun. I bought the RRA 9mm upper and a RRA .223 lower and installed the 9mm hammer. I did not want to use a bottom loading mag block, so I went with an ASA top load block that works great. Because there were not many mags that actually activated the bolt catch and Colt mags were almost non-existant during the ban, I just used RRA modified Uzi mags with my ASA block which does not activate the bolt catch.

Now that ProMags and C Product mags are available and will activate the bolt catch I decided to change my mag block to one that will hold the bolt open. I still did not want to use a bottom loading block,  so I chose the Hahn dedicated mag block. My gun would not run at all with this block. I could not fire two rounds through it due to ejection problems. I tried a few things with a local armorer and was going to contact Hahn for assistance, but Hahn only has an email address for technical support on their website. I finally decided to return the Hahn block and ordered a RRA bottom loading block.

When I got the RRA block I turned my gun upside down and installed the block with the ejector just contacting the bottom of the bolt and tightened it there. The gun has run 100% with this block installed with both ProMags and C Product mags.

I am not bashing the Hahn block at all, just passing on my experience. I dont think that the ejector in *my* Hahn block was close enough to the bottom of my bolt and tweaking it didnt solve the issue because the ejector was slightly loose in the block. I don't own the correct punch to partially remove the bolt catch on my lower in order to keep messing around with the Hahn block, so I chose to use something else.

To the original poster: my empty cases were never leaving my upper receiver and were getting caught in front of the bolt, between the bolt and charging handle, under the bolt by the hammer and so forth. Jams that were very difficult to clear after every round fired. Sound like the same issues that you are experiencing?

Yep, those are the same failure to eject issues I am getting.  I contacted someone from Hahn using their tech email (quick reply for the holidays, I am surprised) and he pretty much said the same thing - that RRA uppers tend to have issues with their mag block.  In some instances, it's because of poor extraction due to the extractor or the pin holding it as others here have stated.  In others, it's simply because the ejector ended up out of place.  Not because there's a defect in the mag block or RRA upper, just that due to the dimensions of the components used, sometimes that's how it is.  In that case, the ejector might need to be modded.

Based on comments in this thread and the info from Hahn, I think I've got a plan of action.  First, try modifications for the extractor.  Mess with the extractor, mess with the roll pin, replace both, etc.  If that doesn't solve anything, then it's time to bend the ejector.  The ejectors are replaceable so if I get too crazy with it, I can fix it up on my own.

I have noticed some wear marks on the ejector where it rides in the bolt carrier channel.  It is possible that this point of contact is pushing the ejector out of position.  Unfortunately, I do not know if it's the ejector or bolt carrier is the culprit.

In my case the extractor was never an issue. My gun ran fine with the ASA block and the RRA block. When I had the Hahn block installed and was having the ejection problem I even swapped bolts with my friends (complete) RRA carbine that was 100%, my bolt ran perfect in his gun and his bolt wouldn't eject brass in my gun.

I just couldn't get enough adjustment out of the dedicated Hahn block in my lower because it was pinned in. even after tweaking the ejector the fit of the ejector was loose in the block. Does your ejector have some play where it is mounted inside of the block? Can you move it around at all?

The ejector has a little wiggle room.  I believe this is by design.  If it simply sat higher in the bolt when mated with the upper, I think it'd be fine (solve the BHO issue at the same time).  As the Hahn tech put it, the ejector was designed for the Colt and should be inline with where the case head should be in the Colt.  The rest of the upper should work around that.  I don't fault RRA, they designed their upper to work with their mag block.  While others have similar builds with no problems, I'll just give my build a little kick in the pants.  Why use a screwdriver when a sledgehammer just feels better?

Er, okay guys, I've been tweaking the extractor for a while now but I can't seem to get it to consistently eject a spent casing when hand-cycling the charging handle.  What it will do consistently is fall straight down the mag well when I don't have a magazine in.  Any secrets to getting a better extraction?  I've bent the extractor straight, not straight, more curved, slightly curved - all with the same non-extracting results.

Also have a new RRA extractor and roll pin inbound.  Maybe the whole darn thing is just whacked out.

Well, I might as well throw my two cents in here.

Take your bolt out of the rifle and place an empty casing in the bolt face.  You should feel some resistance as the rim of the case pushes the extractor aside.  If you don't, you need more bend in the extractor.

Now take the casing and try to push it sideways against where the extractor is holding it, as if you were trying to pivot it out of the bolt face.  If it easily breaks free of the extractor, then the claw of the extractor is out of spec and isn't gripping the rim of the casing.  There are variations in the rim thickness of 9mm casings, so this can show up with some ammo, but not with other brands.  You can attempt to open up the claw, but it's a ticklish job and it's much easier just to replace it.  Since you have a new extractor coming anyway, I sure wouldn't bother with it.

The ejector has to be in the bolt slot as high up and as close to the right side of the slot as possible without actually causing significant drag.  Even if it causes some light drag, leave it that way and it will wear in for a perfect fit.

It's a very simple mechanism, but in order for it to work two things have to happen:

The extractor HAS to hook the rim of the casing- not just rest against it.

And the ejector HAS to reliably contact the casing.

Once the ejector is properly positioned, you shouldn't have any further troubles with it unless you somehow bend it.  Once you get a properly dimensioned extractor in place, it will be fine until the hole it lives in get filled with gunk and it doesn't grip the casings any more.  Clean it out once in a while and you should be all set.

Hope this helps.

Quoted: Er, okay guys, I've been tweaking the extractor for a while now but I can't seem to get it to consistently eject a spent casing when hand-cycling the charging handle. You actually need to "snap" the bolt rearward in similar fashion as the bolt cycle when fired  What it will do consistently is fall straight down the mag well when I don't have a magazine in. Install a mag with dummy rounds.. Do your inspections in the normal operating conditions the rifle would be in to verify function. Use dummy rounds if you is a handloader, or at a minimum, remove the hammer so it not hit fire pin if accident were to happen.. Any secrets to getting a better extraction? Look at your headspace also.  Pull upper, remove extractor, place round in chamber, and close the bolt..  Now take a tiny screw driver and try to move the round forward-backward while holding the bolt closed.  If it move, you need/should correct headspace so the case stick out of barrel end far enough to snap under the extractor hook.  I set mine up for .130" case protrusion..  If you suspect headspace, I have local AR15 member who does all my cutting and I can have him correct the issue (face barrel end, then set barrel back same amount).. not hard if you understand what is supposed to happen. I've bent the extractor straight, not straight, more curved, slightly curved - all with the same non-extracting results. Also have a new RRA extractor and roll pin inbound. Go to LOWES and buy a 1/8" x 3/4 roll pin (in the blue drawers marked "tension pin") Maybe the whole darn thing is just whacked out.

Quoted: When I used to hand cycle my 9mm AR I wasn't always pulling back on the CH hard/fast enough to produce the same amount of reward energy as when the gun was cycling during the firing sequence.  As a result, rounds didn't always eject well.  Might that be your issue here?

It's possible.  I was hoping to at least verify some improvement in extraction before I pack everything up for the range.  I don't think I can stomach another trip just to see the same failures.

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Same problem with RRA setup.....

New extractor pins solved mine

extractor roll pin from home depot, much better fit than RRA.  RRA has been having these issues with a 3 cent part for years, don't understand why it hasn't been fixed.

Also, I found that an ASA block is more consistent than a Hahn.  Go figure.  I had to polish the top of my extractor because the bolt was riding on it.  Works fine.

Twiddle thumbs.  It's been more than a week now and I'm still waiting for the RRA extractor.  Bleah.

Anybody know where I can buy a complete Colt 9mm bolt carrier?

Quoted: Twiddle thumbs.  It's been more than a week now and I'm still waiting for the RRA extractor.  Bleah. Anybody know where I can buy a complete Colt 9mm bolt carrier?

Why you want a high $$$ COLT 9mm bolt ? Gonna cost you near $400, can get  2  Garrison bolts for that money, and some spare parts.

Call Kent at Garrison Mfg Inc for his spare parts.. I have his 9mm bolt from early 2003, no problems here.

Wow, now that you pointed them out, maybe I should've bought a complete bolt carrier from them instead of buying just the extractor and pin from RRA.

I ordered a complete RR bolt from PKfirearms which is temporarily on BO.

Quoted: Quoted: Twiddle thumbs.  It's been more than a week now and I'm still waiting for the RRA extractor.  Bleah. Anybody know where I can buy a complete Colt 9mm bolt carrier? Why you want a high $$$ COLT 9mm bolt ? Gonna cost you near $400, can get  2  Garrison bolts for that money, and some spare parts. Call Kent at Garrison Mfg Inc for his spare parts.. I have his 9mm bolt from early 2003, no problems here.

+1

Quoted: Same problem with RRA setup..... New extractor pins solved mine

You have to look at the pin if its a spiral pin its shit you need a roll pin.My RRA bolt had a spiral pin after 100 rounds the cases were getting stuck straight up and down in the action so i removed the bolt and that spiral extractor pin was half way out replaced it with a roll pin i beleive its 1/8" pin and have not had any problems 1000 rounds later. Thanks Mike

ETA: A spiral pin is rolled steel and a roll pin is like a spring pin and has tension in the hole where a spiral pin is just rolled steel it fits tight but with all the slamming of the bolt they just dont hold.

Lo and behold, the RRA extractor and pin was waiting for me when I got home.  I compared it with the original and the only difference is that the nubby part below the claw area seems less thick which would allow more of the claw to "bite" into the case rim.  The roll pin (confirmed as not a spiral) was the same as the original in dimension.  I will upgrade this to a quality tension pin from a hardware store like others have suggested.  Finally, I'm going to try a variety of ammo with a variety of mags.  I've got Colt, modified Uzi, Promag, and CProducts mags and CCI Blazer Brass and Speer Lawman ammo.  Hopefully I can find some Federal and Winchester before I hit the range this weekend.

Okay, it's got a heartbeat now.  Installed the tension pin I got from a local hardware store.  I followed the advice of getting a 3/4" length one so it's 33% longer than the RRA one.  It's also thicker or stronger steel because it took much more effort to pound it in.  When hand cycling, a spent shell flops out of the ejection port.  Will report back after I hit the range this weekend.

The two RRA pins did stay in place.  They never dropped far down enough to ride in the channel as you experienced.  But, I did notice the spiral pin for the bolt weight was sticking out of one side.  It wasn't rubbing the upper but I hammered it in just in case.  I think RRA just uses a lousy roll pin for the extractor.. silly that a $0.25 part from a hardware store will hopefully fix it. /cross fingers

Gentlemen, today is a glorious day.  I, with the help of you all here, have transformed an absolutely unreliable firearm into a reliable monster that eats everything. The thing ran like a champ without a single failure, gobbling up all sorts of ammo without a hiccup.  The amazing thing was full dumps with all the different magazines including the Promag was flawless.  Bold hold open worked every single time (minus the modified Uzi, of course).  Sirs, I thank you.

For those curious what I tweaked to get my build working, here's the things I did.  To get the BHO working, I had to remove some of the material from the bottom part of the bolt catch where it hits the side of the lower.  This allowed the bolt catch to rotate higher to engage the bolt.  To fix the poor ejection, I had to replace the extractor and use a "super-sized" roll pin to hold it in the bolt.  For future reference, I used a 1/8" diameter, 3/4" length tension pin from a local hardware store.  When troubleshooting your own build, I'd start with a new tension pin before replacing the extractor.  In addition to the extractor, I bent the ejector claw so that the leading edge sat as close as possible to the bolt as pictured.

Quoted: Gentlemen, today is a glorious day.  I, with the help of you all here, have transformed an absolutely unreliable firearm into a reliable monster that eats everything. Knew it  would come about... I got my new barrel back for thread, and shot a mag of suppressed Saturday, now to finish assembly of the barrel. For those curious what I tweaked to get my build working, here's the things I did : To fix the poor ejection, I had to replace the extractor and use a "super-sized" roll pin to hold it in the bolt.  For future reference, I used a 1/8" diameter, 3/4" length tension pin from a local hardware store. That was kind of a given... you have a Rock River assembled bolt, same topic pops up every couple days where poster list out all his parts and there is a RRA bolt in the mix.  Mine worked from the first round, but I bought a Garrison because they was in stock, local, and he called me at home the same evening I had e-mail them, and ordered right there on the phone at like 7-7:30pm when Kent called, he said it was "COLT" spec.. When troubleshooting your own build, I'd start with a new tension pin before replacing the extractor.  In addition to the extractor, I bent the ejector claw so that the leading edge sat as close as possible to the bolt as pictured. Stupid COLT design eje tor, but that is just a result of tolerance stacking when being assembled from a pile of parts, you found that there was some minor fitting involved, and you did it per instructions and pics posted, now you can enjoy the 9mm AR-15.

this seemed to work for me too.

a quick question though, after replacing the pin.....did it seem to "break in" after that? i replaced mine and it still malfunctioned a few times, but since then has been flawless.

Does it matter which side to punch out the tension pin to remove the extractor?

Quoted: Does it matter which side to punch out the tension pin to remove the extractor?

Hit it Martha,,, drive it out either direction..  Use a 1/8 x 3/4 roll pin upon re-assembly.

Just make sure it is centered, so each end of the roll pin is supported by bolt material.

If you use a 1/8 by 3/4" tension pin, you just have to make sure the pin is flush with the carrier key at top and the bolt channel on the bottom.  It's like the 3/4" is a perfect match for the bolt.

For Shamus, mine worked right from the get-go after the mods.  I ran each type of mag with 5 rounds for test.  After they all worked, I went to full mag dumps.  Success!

How does the tension pin itself cause malfunctions other than working out of its channel,or is that the only problem?

If it worked its way out of the hole, it could strike the upper and cause friction.  Also, if the pin diameter isn't large enough or if the pin material isn't sturdy enough to hold the extractor in place during cycling, the empty case won't be held against the bolt face for a solid hit on the ejector.

***tag***