What year did the military quit purchasing 20s? I can tell you I saw 20s as late as '97. But where they just left overs or were they still being purchased? Did the 30s emmediatly replace 20s or were 20s still being purchased much later?

Can't answer that but I took 4-20rnd Colts from the arms room to Afghanistan and used them for straight tracers to spot for 60mm mortars circa 2009.

They're still around (I'm using them to this day) but the problem is the supply-types keep finding them and getting rid of them.

My impression in the early to mid 1980s was that the 20 round magazines were no longer being procured, but that there was a bunch of them still in the inventory.  

I preferred the 20 round magazines in the M16A1 we had at the time as they were more reliable than the 30 round magazines - due in part to the condition of many of the M16A1s at that point, and due to condition of some of the 30 round magazines. They seemed to like to store magazines in 30 and 55 gallon drums and the 30 round magazines didn't respond as well to that treatment as did the 20 round magazines.  The 20 round magazine also allows for a slightly lower prone position, which is an advantage.

http://magfaq.tripod.com/mags1.htm#2a

1971.
They just made a lot of them.

A friend of mine in the Ohio reserve in a motor transport unit from the Mansfield area was sent over in late 2003.  They were driving 5 ton trucks from Kafji to where ever needed.

They had trashed A1's with as many A2 upgrades as they could get on there and all 20 round mags.

He brought home a huge stash of 20 rounders on his 2 week leave and said they were just issued  30 round mags and were told to make the 20 rounders "go away".

Pretty low on the totem pole, but they were issue to at  least one unit that late.  Their mags were in decent condition so they had either been issued somewhat recently or had been used little.  My strong impression was that they were used little.

I used 20's for the whole time I was in the service, which started in 1979 and I retired in 2006, I desk jockeyed for a good amount of time after 1991, but still got to the range every once in a while and still had 20's, I never actually used a 30 in the field or combat.  I know guys that are still using 20's to this day, but most of the time it is 30's.

Last one I saw in use while deployed was 2008.  There are millions of these in arms rooms all over the country.

I never saw any 20s in the army but then again I was a desk jockey.  


Only 20 I do have experience with my is the Colt mag that came with my 6940 (gave the gun to my exwife but forgot to give her the mag but now I kinda like it).  It lives in my truck gun, a 6920.  Next to the rifle are a dozen aluminum 30s in an Ace Case bag but with the gun already being so tall, I had to find a shorter mag if I wanted one to fit in the locked container I use for my truck gun.


Ya I keep 380 rounds in my truck

This may not be relevant, but I like to use Colt 20rd mags for zero'g my rifles and some drills where I want to practice reloads.  I have four from back in the Restricted Roll Mark days.  The guns are gone, but those Colt 20rd mags are still 100% functional.  I probably ran 500rds through the four over the weekend.  They have the evil black follower but work 100% (even with HP ammo).

in 2003 our psyops attachment got a huge box of 20 rounders  that we quietly  acquired as when we found it unguarded.

The Military loves to keep magazines.. The Guard and Reserve units I were in loved them for the 40 rd Qual.

Someone would write "BAD" on them with a sharpie and still hand them out....

I cannot confirm or deny that a handful of Colts and Adventure line and Cooper 20 rds may have made it into my gear boxes....

I'm sure there are still plenty of 20 rd's stashed in Arms rooms all over CONUS.

I guess I'm a turd, but as a retired 11B I admit to bringing 8 original issue M14 mags home from Berlin in 62.  Then at least 10 Colt 20 rounders from where I was in 66-67.  I had a break in service for 5 years then went to the 19th Group and was in charge of marksmanship for my detachment and somehow a dozen Colt 30 rounders ended up in my duffle bag.  I transferred to an Armor unit as the Scout Plt Sgt and took teams from the battalion to the All Army matches for 8 years and darned if the Supply Sergeant told me to get rid of 100 twenty round mags or he would pound them into powder.  At the same time I had to rescue a hundred or so 1911 mags, some still in the wrap with 1945 as the issue date.  I passed these out to guys on the various rifle and pistol teams, keeping a few for myself.  

You guys who are civilians often don't understand that the supply sergeant and armorer can get rid of things that are DXed because they really just take up limited room in a connex.
I saved 2 1911 mags with 1945 markings.  All of the M14 mags because I have pictured of my firing in the 1961 and 62 Leclerc matches, and only 4 original Colt thirty rounders.