I've been thinking of grabbing one of these for my Series '70, but I'm kinda turned off at the thought of $35 magazines.  I know that Metalform makes Colt Ace mags for a good bit cheaper, and there may be other sources of mags... has anyone tried one of these with their Ciener kit?

I haven't tried anything other than the Ciener magazines for the 22 LR Conversion kit for the AR-15, BUT...my understanding from a post somewhere on the AR-15 boards was that Ciener kits were proprietary....meaning, other manufacturer's magazines would not work with the Ciener conversion kits. I would assume this is true for the 1911 conversion kits as well. Maybe someone else will know for sure.

Again I owned both and never tried this but:

the Ace mags have a MUCH heavier spring made neccassary by a faster cyclic rate and stronger recoil spring.  

I don't think they would be compatible but I am not sure.

What do you save? $10 a mag to go with ACE mags?  the ACE mags are a total bitch to load and that to me is not worth the savings of $10.  I could pop off 500rds a day with my ceiner but the ACe mags are so hard to load (even with my loading tool) that I am lucky to get off 150 rds in equal time with my Marvel kit.

Quoted: the ACE mags are a total bitch to load and that to me is not worth the savings of $10.  I could pop off 500rds a day with my ceiner but the ACe mags are so hard to load (even with my loading tool) that I am lucky to get off 150 rds in equal time with my Marvel kit.

Very valid point... I've never experienced any of these kits before, and I think that I'd be willing to pay a little extra for mags that can actually be loaded easier.

Does anyone know of a cheaper mag source than $35 directly from Ciener?

I have a Colt ACE kit and a JAC (Ciener) kit both.  The ACE mags will NOT work in my JAC kit.  I can't help on other sources for the JAC mags.  Several years ago I came across someone who was closing them out and I bout 2 for (if I rememebr right) $20 each.  I haven't looked for them since.