I've already gone the cproducts route and well obviously that didn't end well. Now I can't decide between the dedicated hahn or the rra. I will be using new cproducts mags with the rib and follower to activate the last round hold open.

I really like that the hahn is dedicated and can't fall out.  But I also really like that you can adjust the depth of the rra if needed.

Any thoughts? yays? nays?

If you are set on keeping the CP mags, you may want to go with the RRA block over the any of the Hahns.

I have the Hahn dedicated block and C Products mags. Absolutely no problems at all. 100% reliable

I use the Hahn dedicated blocks in my 9mm AR's and I have always been 100% satisfied with them!!

Go hahn dedicated with metalform mags and be done with it.

Which one uses the standard bolt catch instead of the 9mm one?

I have 3 Hahn blocks, 2 dedicated top and 1 bottom load and all of them work great with Colt, CProducts and MetForm mags.

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These blocks        Item #: A9CSRD0405
                          Item #: A9CPRB0402
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http://shop.hahn-precision.com/category.sc;jsessionid=E919718D862AF5625A97A9003C2144A5.qscstrfrnt01?categoryId=11

Thanks

I use the Hahn dedicated upper and CP mags. I haven't had any issues.

Tough call. I have the dedicated Hahn and CP mags and they do not run 100% together. I not sure where the issue lies right now but have been too busy with other stuff and haven't had time to mess with it.

Outside of that, I kind of wish I went with the RRA block (or the Hahn bottom mount) because my 9mm lower is a registered SBR so it would be nice to be able to quickly remove the block to use the lower with other uppers\mags.

On the flip side (and I have no idea if this is BS or not?) but this was posted over on Lightfigter.com by "Psywar1-0"... 9mm ar sbr

Like I said, no idea if it's BS or not. It sounds plausible but then again, a lot of people are using the RRA block and I have yet to see or hear about a busted received?

Every thread attracts a different mix of users - I think if you read through all of the threads out here on 9mm setups, they will show that a higher percentage of people have issues with Hahn blocks and CP mags and require substantial work to the mags, blocks, or both to get reasonable functionality, than those users that claim 100% success.  For RRA, I think most users have been able to get some reasonable level of functionality with CP mags by merely tweaking the position of the block.

Good luck with whatever you end up choosing - make sure you post up your experiences either way.

My Hahn Bottom Mount works flawlessly with my CP Mags. Not sure why so many people go with the dedicated set up.

I think some of the problems with CP mags are what batch you get your mags from.
I purchased 10 from one vender and 5 from another and the 5 must of came from
a different batch because i had 2 of them that had a little mag lip drag on the port side and
the other 3 just enough to skim the finnish off the lip.
I took my mic and found the difference was the feed lips between the 10 batch and the 5 batch.
The lip drag was not enough to cause problems but I didnt like it, easy fix with a few strokes of a file.
If you have the $ just get the MetForm mags/Spikes mags and be done with it unless
you like to tinker and fine tune then go for the CP mags.

My Hahn and CP mags are great as long as the ammo has a long nose and length like WWB. Shorter rounds sometimes nosedive.
and I did no tuning

1+  What he said.

thanks for the answers everyone

Can someone explain the difference between the dedicated, top, and bottom 9mm Hahn adapters?

bottom - slides in from the bottom of the magwell - has a built in actuator that works in conjunction with the std. bolt catch to provide LRBHO - get this if you want to switch between 9mm and other calibers quickly and retain last round bolt hold open LRBHO

top - slides in from the top of the magwell so it can't ever fall out - has no actuator so when used in conjunction with a std. bolt catch, there is no LRBHO - you can use this block and still switch between 9mm and other calibers fairly quickly

dedicated - kind of a cross between the top and bottom blocks in that it is a top load with a built-in actuator - you must remove the std. bolt catch to install/remove the block and it has LRBHO capability - not the ideal solution if you intend to switch calibers much

Note - you can use the top loader with a 9mm bolt catch which effectively turns it into a dedicated unit with LRBHO - the advantage over the dedicated unit is that it is a little cheaper to go this route and you have less moving parts to worry about - the follower acts directly on the 9mm bolt catch instead of having to push up on the built-in actuator which then pushes up on the std. bolt catch for LRBHO - older blocks had tighter tolerances and sometimes the actuator could bind when dirty and not activate the bolt catch, Hahn has supposedly changed their tolerances to reduce the likelihood of that happening but I can't say whether RRA or others have also

I prefer the hahn dedicated if it's going to be strictly 9mm. If you are going to swap back and forth then go RRA.

I have a Hahn and love it.  Installed easily and adjustments(bottom load) are also easy to complete, though I've never really needed more than one.  I run modded UZI mags, Colt mags, C Product mags and Promags with NO PROBLEMS.  

The only small issues I have from time to time are with a couple UZI mags due to the previous owner removing too much material from the mag catch area of the magazine.  Other than that, lots of flexibility in the Hahn block regarding mag use and they make great products.

I have both, one each in two different rifles.  I have not had a problem in either one with C-prducts or modified uzi mags...

Dan

I had both. Ether is fine. The RRA will allow you to put it in other rifles easier.

Has anyone had any experience with modded uzi mags from m60 joe?