Ok guys, I know there was a recent thread on this but I cannot seem to find it so my apologies.


But anyways, I need one that is easily removable so I can go back and forth between 5.56 and 9mm as quickly as possible.

From my understanding, its either a Hahn ( http://stores.9mmar.com/hahn-precision-bottom-9mm-magwell-block/ or http://stores.9mmar.com/hahn-precision-top-magwell-block/ ) or the Spikes ( http://stores.9mmar.com/spikes-tactical-enhanced-9mm-magwell-block/ ). The bolt I'm using is a MAS Defense ( http://www.shop.masdefense.com/9MM-AR15-BOLT-CARRIER-GROUP-9MMBCG.htm ) if that matters.

Thanks

I love Spike's stuff and have bought quite a few items from them, but IMHO Hahn makes the best mag block, period. When I bought my Hahn block it was the only one that had feed ramps, if that's still true that's the best reason to go Hahn. Based on all the posts I've read if you go with a Hahn top loader you'll have best luck with Metalform mags.

FYI Hahn makes (or made) two types of top loaders, dedicated & non-dedicated. I wanted to quick swap my 9mm & 5,56 uppers on the same lower so I went non-dedicated. The difference is the non-dedicated uses the stock AR latch which allows for easy removal but doesn't hold open on last round. Later when I picked up a lower to dedicate to my 9mm build I added a long finger bolt catch ( Colt & RRA make them) for last round hold open. So now I can't remove the magwell block without removing the long finger bolt catch.

My vote is for the pro mag block. Works flawless in my SBR.  Easy to swap.  Was cheap.   Only have about 200rds through it so far but not one issue.

I have used more RRA than any other mag block.
They swap very fast and have always worked.
Mount them as low as you can, just so the mag catch is free to move

Have Spikes, and ProMag as well. ProMag is great for the money. Spikes has a tilt adjustment.

That said, I always go back to RRA.

Oh one more thing...
I had an early production American Spirit Arms mag block.

If you find one used:
AVOID it like a $3 hooker.

I almost gave up the AR 9 m.m. because of this POS.

And while I have your ear...
I sent my first TWO back to America Spirit because the geometry was WRONG.
I tried three total.

I sent the third back as well.

Don't buy an American Spirit Arms mag block.
OR 3

I had to explain myself. sorry for the rant.

Alright, just an update, my cheap bastard side to over but I was able to snag a Spikes for a really good deal and just went that route. Guess I didn't take yall's advice but figured it was too good of a deal to pass up ($100 never used) on one that (seemingly) get a unanimous yes

I used this 9mm magwell.  It has worked awesome.  I think they manufactured the spikes tactical magwell conversion from the looks.  

get this one