ar15 conversion to 9mm?

[erniestu]

I'm looking into a 9mm conversion kit so I can shoot my AR (Colt A2) in local IPSC matches that require pistol caliber only. I see that RRA has a 9mm upper available, with what looks like only minimal mods necessary to switch back and forth. Does anyone here have experience with this or other manufacturers' conversion kits and are there any pitfalls I should be aware of?
Is it reasonable to swap uppers (+hammer, buffer, etc) relatively easily when I want to alternate chamberings?
Thanks for your input.

Apologies if this belongs in the 'smithing section.

 

[Ed]

Very easy. You also need a mag block. It can be done in less than 5 minutes.

 

[erniestu]

Thanks Ed.
From folks that have used these on a Colt lower, is there any reason to choose the RRA versus the Olympic Arms 9mm upper? RRA looks to be a fair bit cheaper but may require some tweaking. I've read that the Oly is a bit more of a plug and play kit, but the upper and magazines are more expensive without a different mag-block.

 

[StealthyBlagga]

Switching uppers is easy, of course. So is installing the mag block. However, the buffer is inconvenient to switch (but a 5.56 can run with the 9mm buffer in place). The hammer is a downright PITA; I suggest you get a hammer that will work with both 5.56 and 9mm to save having to change it out every time you change uppers.

I don't have much exposure to the semi-auto AR15-9, but the M16-9 subguns I've seen don't run worth a ****.

 

[Keith Wheeler]

The folks I know who have reliable 9mm ARs use the Uzi mag adapter block (not cheap, but most of these guys also have Uzis, so why not make use of the high quality mag you've already got?)

As much as I'm interested in having a 9mm AR upper (love the DEA style with the built in suppressor!) I don't know too much about them. That said, it is my understanding that some uppers work with the Uzi mags and some don't. I _think_ (someone please correct me) that the RRA uppers are "Colt style" and will work with Uzi and Colt mags, whereas the Olympic uppers are different.

 

[Ed]

I changed a hammer last week with no tools and just a punch in 40 seconds. It is not hard. We removed the buffer in the Army when we cleaned M16's. Again, you hold down a detent and pull. Less than 10 seconds.

 

[10-Ring]

There are 2 conversions - one is the Colt type that uses Colt rare & expensive mags and the other type that uses Sten mags that are in huge quantities and uses a slightly diff't mag block.

 

[clown714]

i have a oly upper on a stag lower.
I run sten mags with a mag block and heavy buffer.
stock hammer.no probs ,yet.
heck of allotta fun.
do need a mag loader for the stiff mag springs.
mag release is on the mag block.

hope this helps.

clown

 

[Keith Wheeler]

There are 2 conversions - one is the Colt type that uses Colt rare & expensive mags and the other type that uses Sten mags that are in huge quantities and uses a slightly diff't mag block.

It's my understanding that Colt mags are just Uzi mags with a different catch cut. The trick to avoid the cost of original Colt mags and to avoid the joy of loading STEN mags is the Uzi mag block, like this one: http://www.brownells.com/aspx/ns/st...p=19669&title=AR-15/M16+9mm+MAG+BLOCK+ADAPTER

It ain't cheap, but of course that depends on what you're building the rifle for and your circumstances. If/when I ever get to finally trying out a 9mm AR upper, I'll get one of those blocks just to keep my stick mag type count down to "one". Used to be "two", but I sold all my MACs and I have no desire to go back to a single feed stick.

 

[Tim L]

C Products is coming out with a magazine for the Colt/RRA 9mm 32 rd mags will be about $30. see http://www.44mag.com/prodinfo.asp?number=CP930. I believe that RRA will be selling them as well, per info from ar15.com

Tim