I have read the many posts on the site. Thanks for all the info to date. I want to put together a 9mm carbine (RRA A4 Upper). I need a 9mm Colt style mag well block that has the BOLT HOLD OPEN FEATURE I will change my bolt catch and use the lower for 9mm only.
1. Buy a two piece COLT orginal and drill my receiver (hope for the best hole alignment)
2. Try and find a new style one peice Colt drop in (J&T is forever out of stock Can't seem to find one anywhere?)
3. Find some other brand that is in stock today ( NEED SOME HELP Here :) )
Thanks for the input
Hahn Precision from Brownells.
Top load requires a 9mm bolt catch.
Bottom load has an actuator built-in and uses a 5.56 bolt catch.
I second the Hanh
Try RRA block, one piece, colt style, bottom load.
I'm sure others carry them...
Garrison Manufacturing Inc.
P.O. Box 231
Wauseon, OH 43567
The 2 blocks I have are Garrison. Top loaders, bolt hold open slot. I use colt mags and pro-mags.
Just pop in a 9mm hammer, drop in block, start shooting. You dont need to use a bolt catch if you dont want. I have broken 2 bolt catches so I dont even bother any more. If you dont use a 9mm bolt catch with the top loading block, you can pop out the block and snap on a 5.56 upper. That simple to change cal.