mdbuckle said:
Ok, now your guys have got me thinkin 9mm for my next build...who makes 9mm lowers?? Are the parts interchangable with 5.56 parts? I am thinkin this could make for a fun little blaster!
5.56 and 9mm lowers are the same except you need a mag block
Mag Blocks
Assuming you are building a RRA / Colt "colt style" system 9 ( vs oly arms ) you can use a RRA mag block. There are 3 Hahn blocks that are much nicer than the RRA but harder to find. These us Colt or modified Uzi Mags
You can also use a VM
Hytec system that takes UNMODIFIED Uzi Mags
Triggers
You must use a 9mm trigger ( RRA good source ) , a bobbed M16 hammer, or a DPMS style
If you are ok with a mediocre trigger pull then this is the way to go . If you want a match style trigger ( RRA NM, CMC and other aftermarket ) you need to get your bolt ramped ( without a ramped bolt you will lock up the works as soon as the bolt goes forward the first time ....you have to take the upper / lower apart to clear jam )
IMO this is the only way to go. I also use my lowers for 9mm and target shooting so I want a good trigger. A properly ramped bolt works for pretty well all triggers
Problem is you will have to take it to a machine shop since none of the ar builders do this in Canada as a service
Another advantage of the ramped bolt is its much easer on your FCG pins . Take a look at a AR 5.56 bolt . They all have a ramp . Dont know why the 9mm colt style bolts dont . Ramping a 9mm bolt duplicates a m16 style ramp
Buffer
Lastly you need a 9mm buffer which is heavier . Easy to change out so no big deal . You can get away with a Enidine hydralic buffer for both but they are pretty pricey