Its a brandnew ASA 9mm on a Bushmaster lower..I've got two new mags and one used mag..all three have the star on the side which I believe means they are IMI...the trouble is that if either mag is fully loaded with 25 rounds I have severe failure to feed problems...the empty brass is ejected properly but the new round does not fully insert....but if I only load the mags to 10 - 15 rounds it operates perfectly!...slow fire or fast fire it will work great, but only with 10 - 15 rounds loaded....what could I do to fix this problem? Thanks for all the help ya'll have given me in the past and for all the new questions I'll no doudt have in the near future..jackpot
P.S....one thing that I failed to mention is that out of the three uzi mags only two can be used...one of the new ones and the single used mag...the other "new" mag won't insert into the magwell / block...It seems like it's "fatter" that then other two, when it gets about 3/4 of the way in, it gets so tight you almost have to force it out...so I guess I'm in need of a few more uzi mags also...on the first concern though...could it be that the mag springs or follower are the problem in some way?....thanks again gang!!!

Ejector rubbing bolt? Black marker it and see

Mag lips need de-burred? (sharp edge holding the brass case)

Heavy brass case marks on the bottom of the bolt? I cut material off of my bolt when I ramped it. The cases in the mag do not touch the bolt now. See pic. The two shiny spots next to the surface that re cocks the hammer.

Mags rubbing bolt? Black marker the top of the mag lips to see if rubbing

Heavy buffer? if not you'll get bolt/buffer bounce

Fat UZI mag must be a Mecgar (sp?), .005 to .015 to wide. They are snug in my UZI SMG too.

Bolt ramped? Re cocks hammer easier subsequently more energy stored in the stock spring to throw the bolt foreword and strip bullets out of the mag

[img]http://users.zoominternet.net/~subguns/after bolt.JPG[/img]

I took it back to the range this afternoon and again the same thing...but its a max of 13 rounds in either mag when it functions great...on the first mag I loaded 15 and after the first & second shots I had to assist it getting the round fully inserted..after that I only loaded the two mags up to 13 rounds and shot 2 full boxes...100 rounds and didn't have not one single problem...but more than 13 rounds and failure to feed in each mag a few times..everytime..dang it!..after seeing your reply joeblack I checked what I could now, no burring noticed....and no brass marks,rubbing of anykind on the bolt...with it being new & having just ran 100 rounds thru it I think that would be easily seen, you can notice down the middle were the hammer recocks and just prefectly black everywhere else...I'll have to check the other "possibles"...
             I was told that the three mags were IMI {all 3 have a star}...,I was thinking of buying a couple of meccgars {spl ?} but dang if they are fatter than these there is no way I could insert them in the mag well....with the block I have ,I have to use the mags with the "rib" on the back, do you know if the meccgars are that way, ribbed?
 Thanks again....jackpot

Can use you the 9mm buffer in your .223 upper, or do you need to change the buffer every time?

I keep my 9mm buffer in.  It works great in .223.  It slows the rate of fire down nicely in .223.  With a regular CAR buffer it was very hard to keep long bursts on target.  I think the recoil is much tamer now too.  Last time out I had no bruises on my shoulder when I did before with a CAR buffer.

ASA makes at least two different sizes of one piece 9mm magwells. I have the larger one and it accepts Uzi, Colt and so far all the different aftermkt mags i've tried including mecgar. I have the block in  an ASA pre-ban upper / SP-1 collapsing stock lower. So far this combo has been able to hum right along with every different type of mag i've tried. I believe the smaller ASA mag well is designed for the slick back mags (No ridge). It maybe provides a better mag stance and gives  more reliablity in ASA lowers. ASA also sells converted Uzi style mags that seem to work well.  Mikke

I've got the ASA 9mm block that uses the uzi mags with the "lip / ridge" that runs on the back of the mag from top to bottom.....I can't seem to find a problem with my ejector or anything...so I guess I'm down to the mags being the culprit or ???...

Hey Jackpot where in Texas are you?I'm in the DFW area.I have the same type set up, and could
meet for mag test.
         wes

I talked with a guy that works over at ASA, drilling him about these 9mm uppers. I am wanting one bad, they really seem like fun.

He says that they have tightened up the inside of the mag well adaptor a little. I was told that the mags with the ridge on the back will work fine.

Maybe take the mag apart and see if you can spot any rubbing points? or burs on the follower. just an idea....

On a prior ASA upper I built I had a lot of ejection problems until I called ASA and they told me to tweak the ejector (on the mag well) a little. I gave it, as instructed, a slight bend to the right and that solved my problem. They don't seem to mind giving out advice over the phone, or at least they didn't used to, I haven't talked to them in a while. It couldn't hurt to give them a buzz. If you can borrow a colt mag give it a try. They seem to work better than Uzi's.Mikke

Hey guys thanks alot!...

              little223shooter...,mikke...,wes1...I talked with a guy at Calvary Arms not too long ago about the ASA uppers and he told me that ASA had came up with a new block, again trying to tighten up the system..anyhow he said that one type of block accepts the "ridge" type mags and the other is setup for flat types...but I can't remember which one he said was the new design...with ridge cutout or flat no cutout...but he did say that both are good blocks and really either would be fine with him....wes1, I live in Ennis..about 30-40 miles south of Dallas on IH45...whereabouts do you throw your empty shells at night?....yeah this thing is a barrel of fun...my 11 year old son loves shootin it...he says the .223 is a little too loud for him but this is great..but I've got to figure out this mag problem..you can go through 13 rounds in no time..and with just two working mags..whew!

I had the exact same issue with mine, got a lot of great tips, none of them worked.  Took it into a gunsmith, and the problem wasn't with the rife or the setup, or the mag block or the bolt ramp.  

Sometimes, these IMI mags have springs that are weak, the fix is to disassemble the mag, and pull the spring a bit and and try again.  This worked wonders for me.  Also, if you keep your mags loaded, all the time it will weaken the spring.  Hope this helps.