Galil M16 mag adapters
I am not 100% sure on these, but from having fired both a semi Galil AR 5.56 and Select Fire SAR 5.56 at Action Arms's old test range in Philly back in 1986, there are three kinds of mag adapters. IMI made a military style mag adapter, which was very well made and had a safety keeper push pin, which prevented the user from activating the Galil flapper mag release and taking out the adpater and M16 mag....those are the best...and used to sell well over $350, and it had the standard side M16 mag release button on the right side. Many of the parts are highly machined and it was very heavy, with a dark parked finish. This model only fit the Semi Galil receiver.
The second model was an IMI adapter often seen in Action Arms boxes, which was just as heavy duty as the MILSPEC style described above, only it did not have the keeper pin to block the Galil receiver mag release. It was also heavy and well machined and dark parked. It fit only the semi Galil.
The third model is the one made by Magnum Research. I beleive it was made in the USA and it is actually not very pleasing to the eye, nor as durable. It was inexpensive, and when you remember that the Galil was one of the most expensive black rifles imported into the USA at the time, having something to allow shooters to fire existing and inexpensive AR15 mags was important. This model had an investment c ast body with front mag retainer made out of heavy sheet metal. You often find them still in the blue Magnum Research boxes.
The only Galil AR15 mag adapter I have ever seen in full auto Galils were used by a Special US Navy test Team in 1982-3. They had full auto Galil SAR's with a specially made side folding stock, not unlike the Mini Uzi, only with a heavy rubber butt adapter. All of the furniture was synthetic, and it used both a modified Colt M203 grenade launcher, tritium iron sights, Early Aimpoint sights mounted to the IMI scope mount that locked into the side of the receiver with a locking lever. All that I saw briefly also had special stainless steel silencers made by a company out of California. I was told the Galil's were a test item, and they were tested with a very early version of the Beta C Mag, which had a weak mag feed tower & the steel AR18 40 round magazine. Armalite was in business then, and the Sterling 40 round mags were the best feeding of all the AR mags.....not unlike the steel HK mags today. I also think they used a special steel 30 round AR mag that also fit the Chartered Industries of Singapore drum fed squad auto....which I do not remember the name of. The CIS rep at the time had a silencer equiped gun with a ton of mags....and he said CIS offered to replace every 30 round magazine in the Navy inventory if the Charter Industries gun was adopted for the SEALs.
Both the Galil's and the C mags were only used briefly. The CIS gun was never used beyond testing. The C mags were all thrown in the Dempsey Dumpster on the end of the range....where the marine gunners sorted them out.....a total of 50 mags. This is when AR nuts paid $500 for a C Mag, since they were only shown in Jane's Infantry weapons journals. The gunshows in Virginia and San Diego/LA had these C mags flooding the market back in 1986.
I can only imagine that the Galil mag adapter will only fit the semi model, since there is a long relief cut at the front of the receiver of the full auto Galil for the auto safety sear and cross pin. This is the area where the mag adapter does not fit into the full auto galil.....and it is the only real difference in the two models.
On the old Galil/Valmet web board there was a very nice comparison of all the models......I did not save any of the info.
I hope it is helpful.
