I just got an email from AIM and they have 20 rounders for $13. Just wanting to hear what you all think of them.

If you look around, you can probably find Okay mags for that or less.

My asc mags had followers that hung up.

You can do better.

Okay or D&H for me.

My bad.  Didn't realize I was in pistol caliber forums.

I love my ASC mags.

I mean if you really want to spend the money you can buy the IWI mags for the 9mm tavor.

Exact same mag with a different logo on the end plate.  People seem to love the IWI but hate ASC I don't get it.

Here are my ASC mags working wonderfully.

9mm ASC mag dump.

the only issue I had was the follower hit the mag block and hung up. The last 2 rounds would be loose.
I took a file and some sand paper to trim up the nose and now they work fine.

Imo RUN!

EDT if they are 556 mags Asc gi mags are okay. 9mm ASC suck

Agreed.
However if you like to play around with stuff that has a good chance of not working, go for it.

Give it a shot and see.  What works for one may not work for the other.

Personally I have had no issues with ASC mags. Again not sure why the IWI Tavor guys have no issues with the 9mm Tavor and love those mags.  The only difference is that IWI is engraved on the base plate instead of ASC.  

If you want to think you have the best spend the money on metalforms I guess.  I would give them a shot and see if they work in your rifle however.

The CP/ASC mags were supposed to be the be all, end all solution when they were developed.  There were supposed to be different designs for different combinations of parts (regular, X and XX designations IIRC) and they have been through quite a few iterations over the years.  Maybe the newest design is better than the past versions, but I personally won't use anything from CP/ASC due to the issues and problems that have been discussed over the years.

When they first came out, I did buy a dozen.  I sent them back a couple times for exchange for supposed better versions and eventually ended up just returning them - they just had far too many issues to simply work as intended.  Some people modded them to work, so to each his own.  I chose to spend ~$30 per mag for metalforms at the time vs. the $20-ish for the CP/ASC, so I didn't have to dick around with mags. Colt did switch from Metalform to CP/ASC mags for a short time, but I believe went back to Metalform due to issues.

Now with Metalform 32s available for as little as $12.99 on sale from PSA, I see no reason to bother with CP/ASC at all.  If one is desperate or likes to tinker, have at it.

they have a thinner wall so they have more play in the magwell.

I think they are solid magazines, but given the variations in 9mm ARs, and some qualities of the mags, they may need some work.

For the 9mm mag with a CMMG colt style 9mm bolt, I had to use a file on the top edge of the feed lips (in line with the bore) to widen it. The bolt was scraping along this edge as it closed.

On a different batch of mags, this issue: on each vertical side of the magazine are 2 slim, stamped, vertical lines. The stamping, even though it only pressed in 1/32" or less, was deep enough at the lower end to cause cartridges to bind rather than be lifted up by the follower. To fix this, I put a strip of sandpaper on a long flat wooden slat, and smoothed this transition down inside of the magazine body. A few minutes of targeted sanding reduced this obstruction and mags then fed properly.

Even given these minor fixes I had to do, for the low price of the mag, I consider them a good buy, since overall they are solid and otherwise well made. It would still be nicer if they adjusted their manufacturing process so you did not have to do this work. They really should fix these issues, and charge a buck or two more, but for now, I can spend 5-10 minutes per mag and get them to run very reliably.

I only have one ASC and nothing to compare it to but had to do the same to get it to run with a Spinta blem bolt. The right feed lip kept scraping a machined face in the bolt channel and was causing the bolt to not go into battery.

Some time with some 60 grit and 320 grit with oil and enough material was removed and the surface polished to a smooth finish. No more contact and the mag runs 100% now.

Bought is as a cheep holdover until PSA has another $13 deal on their metal forms. Couldn't justify the price of Brownells knowing PSA sells them cheap.

They don't work well in my Colt. Get Metalform or the ones they make for the gun companies.

I would stay with Metal Form. I also have ASC and C Products (same mag) and I have feed issues with them. ASC works great with round nose FMJ full length ammo but everything else is a crap shoot.

Had a couple that would not work right.   Looking at the followers, I noticed they seemed tipped.   Took them apart and found the springs were in wrong.   Fixed and then the followers looked right.   They work just fine now.   32, 20 and 10 round.

Dumb question, but how are the springs supposed to fit in the mags?  The end of the spring toward the front of the follower or toward the back?  I've got a bunch of ASC mags and I want to make sure the springs are installed correctly.

FWIW, I had to modify the feed lips to work on my Spinta blemished bolt.  It wasn't a big deal.  I found instructions on the size to open them up to on the web.  I also took the time to sand down the front of the follower.

Not knocking Spinta, but the issue wasn't the magazine.  From what I was able to learn, bolts are built to different specs.  The Rock River style bolt was built to work with converted Uzi magazines, so the feed lips are wider.  I don't know 100% for sure, but the Spinta bolts appear to follow the Rock River design.

The original Colt 9mm SMG and mag was based on a modified Uzi mag.  Rock River just followed Colt specs/design.

As far as CP/ASC mags - I have seen them with springs installed multiple ways right from the factory.  If they aren't working properly, try installing the spring the other way and see if they work better or worse than before.  There have been multiple threads over the years with all the mods people have done to them and what they think is the best setup to get them to at least run.

It's been a while since I've messed with CP/ASC mags, but the best option is to at least get the latest version, modify the feedlips and other areas that need it, and replace the follower and springs with metalform follower and springs.  I believe the old style plastic metalform follower fits without issue.  I don't remember if the metal metalform follower fits without issue.  By the time you are done with that, you could have just bought the metalform mags though...

Back when I started the 9mm game, the only options for mags were $50-100 Colts and modified Uzi mags for $10-15.  I bought a couple Colt mags to have and the other 50 or so mags I bought were modded Uzi mags.  When Metalform started selling direct for ~$30/mag, I started selling off my converted Uzi mags and picked up a dozen of those.  With PSA selling Metalforms for $13-20, there is little reason to buy anything else these days.  To each his own though.  I'd rather buy 6 metalform mags for $20 each than 9 CP/ASC mags for $13 each.

ASC mags have been flawless in my CMMG MK9.

I will stick with Metalform,PSA has them on sale for $19 every so often.

I have one asc mag I bought in a pinch way back when metalforms were a little hard to come by, it works just ok with my colt pattern qc 10 lower after shaving the follower down a bit.  No real issues with feeding, just have to slam it in hard to fully seat and it won't release freely like the metalform mags. It does seem a little wider in dimension as someone stated.  I really don"t use that mag anymore now that the metalforms are readily available and I have stocked up on them.  Metalform ftw.

I've only used metalform in my dedicated cmmg that I've had for years with no problems.

A friend bought a new cmmg dedicated last year and was looking for mag advice so I told him that everybody seems to say to stick with metalforms.  Bought some and had nothing but double feeds.  Tried some of my metalform mags in his gun and still got double feeds.  Put my metalform mag back in my gun and perfect feeding.  Spoke to cmmg customer service and they say they have had the best luck with asc mags so he bought some from them and the thing runs perfect with them.

As others have said, feed lip dimension is the main issue. I have 4 20 rounders that worked well after a little grinding on the right lip. I have also found them to spill rounds a little easier than metalform mags when aggressively inserted on an open bolt.

I'd pretty much say that if your build won't run ASC mags there's something wrong with the build or the builder himself.  Have 3 diff 9mm Guns that all run ASC and metalforms just fine, one dedicated lower, 2 with mag blocks, kak and Hahn zero issues

Im using them here in California as 10/30 mags and some 10 normal mags as well..they work fine. I have several original Colt 32's and they work the same..havent had any troubles so far.

I have quite a few 20 and 32 rd ASC 9mm Colt style mags . The only problem I had with a few of them was some flashing had to be trimmed off of the followers to allow it to come all the way up
Other than that, they work great in my DDLES Colt style lower with Colt 635 upper.