What is the general consensus on the sten mag conversion for the Mac 11-9? Do they work well? Worth the money to switch it back to original configuration for use with Zmags or just stay with Sten setup. How does having a Sten mag conversion affect the value of the gun these days?
Two of my M11/9s have a Wheatley STEN grip-well. My personal opinion is the STEN mag is a better mag than the Zmag. A lot of folks don't like STEN mags because they're impossible to load to capacity without a loader...but then so are a lot of other dual-column / single-feed high-cap magazines. The other "knock" is that STEN mags are notoriously unreliable and some high percentage will always by "bad"...something I believe that gets repeated all too often by folks who don't even own any STEN magazines. The only STEN mags I've ever culled were the ones that had obvious damage (feed-lip and body dents) from mis-handling or bad storage...I use the STEN mags I have in 2x M11/9s and 2x STEN Mk5s without issue.
When I did the 1st STEN mag conversion on one of my M11/9s, I ran 5 full magazines in succession with each mag filled with a variety of bullet types...from FMJ, to Truncated Cone to Hollow point in both lead and jacketed bullets. Not a single malfunction or failure to feed with those 1st 5 magazines. And yes, the 50rd Lanchester mags are just as reliable. I was so impressed, that I went ahead and had a 2nd M11/9 converted for the STEN grip-well. This was back in the 94 AWB days where the only other option at the time was the factory Zytel mags and the price had inflated to over $200 each. Eventually C&S Metall Werkes converted and brought to market a bunch of Madsen 50 smg mags converted to fit the original M11/9 grip-well and the PAM2 mags came sometime after that...both of which slowed STEN mag conversions for the M11/9 way down.
For me, I wouldn't pay to have my 3rd M11/9 converted to a STEN grip-well. At the same time, I would also not pay to have my (2) STEN-M11/9s converted back to an OEM grip-well. With regard to affecting value? I think 50% of the market will view the STEN grip-well as a negative, 25% would see it as a positive and 25% would not care one way or the other as long as the conversion was done properly and the gun runs reliably.
Anyway, my opinion...good luck.