I am currently looking into purchasing a complete 9mm upper receiver for one of my M4, intended to use as a practice unit for indoor range (indoor range here only permits pistol caliber carbines).  I am looking at the following combo, and need advices:

Complete Colt AR-6450 conversion kit with bolt $700, plus ASA mag block approx. $150
ASA complete conversion kit with mag block for $750.
RRA complete upper for $450 plus ASA mag block for $150

I understand that I need ot have the bolt shaved, so I can use my standard AR hammer.

I would like some recommendations, and suggestions on other work that needed to be done?  Although this is only a practice only conversion, I do like to have a combo that is free from functional problems, and field accuracy (2 to 3 MOA).

Thanks in advance

Leungken

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Unless you are really worried about the "dancing horsey", save your money and buy an ASA or RRA. As a minimum, you will need a 9mm upper assembly, and a mag adapter of some sorts.... If you really want to go cheap, buy a barrel blank, machine the chamber end to fit the upper, chamber it, and shoot it using a scope or dot. Front dimensions are optional>> no gas system to worry about... My SBR 9mm barrel from blank.
[img]http://www.imagestation.com/picture/sraid58/p726e8449982866f7c043f7d68ede5a26/fc681fb5.jpg[/img]

What is the difference in your "conversion kit" for $750, and the complete upper for $450, add $150 for the block?? Does the upper come with a bolt? That is the only reason I see it being cheaper.. You will nedd some kind of upper, and a way to hold your mags.[/blue]

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Read page 1, lots of info, and good pics:
[url]http://www.ar15.com/forums/topic.html?b=3&f=15&t=108261[/url][/blue]

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Read the 9mm threads here and in the "AR General" forum.  Advise you remove the extractor from the bolt, and use a sized case, or a loaded round to visual the headspace, as the extraction-ectractor grab are dependant on correct dimension. This thread is made to sound a lot worse-harder than the problem is to repair, I simply had my barrel "faced", and set back to repair my problem, joe is working the right idea, but from the wrong end I feel, but it HAS worked for him.
[url]http://www.ar15.com/forums/topic.html?b=3&f=15&t=168500[/url][/blue]

I already have a 9mm upper setup but am trying to help a friend get one.
I noticed that [url]http://www.m-aparts.com[/url] has complete 9mm uppers w/ bolt and charging handle for $450.
Sounds like a real good price.  They say the barrels are by Wilson.
Anyone know if these are any good?
I never bought anything from them.
thanks

Correction, RRA's upper conversion kit is $450, with no mag block.