I unfortunately live in the People's  Republic of Mass. I have a high capacity LTC but I am restricted from buying AR-15 mags manufactured after 1994. So to compete in 3-gun I have to buy old AR-15 20 rd and 30 rd mags. I bought a bunch and one thing I noticed is they frequently fail to make the AR go to slide lock when empty. By contrast the new stock 10 rd magpul mag goes to slide lock every time when empty. The are no problems with these mags with respect to failures to feed and the springs are strong. Any ideas on how to solve this?

I also have one 30 rd mag that clearly has a weak spring and misfeeds. Is there a way to refurbish it like I do with my glock pistol mags.

Thanks

PS a retired USMC armorer saw the mags at the range and recognized them right away. But at the time the I thought the failure to go to slide lock was due to a an adjustment needed on my gas block system. I've completed that adjustment

and http://www.midwayusa.com/product/118265/ar-stoner-magazine-rebuild-kit-ar-15-for-30-round-aluminum-package-of-3






 

I would install a new CS spring
Magpul Gen III followers (in the 30 rd mags)
Magpul Ranger L floorplate (again in the 30 rd mags)

I am buying the rebuild kit but several of my GI mags appear to appear to be in pretty good shape and the AR still does not go to slide lock are you all sure the refurbishment will fix this issue or is there something different about the old GI mags than the magpul

It's hard to know without seeing them.  But there are only a few to things related to the magazine that would cause this problem.
1) The spring is weak.
2) The follower is worn down where it engages the bolt catch.
3) The magazine body is deformed.
4) The inside of the magazine is dirty.

The new spring and follower of in a rebuild kit will fix 1 & 2.

I agree with PursuitSS's recommendation.  CS springs are said to last longer than SS. Magpul makes the best follower. The padded base of the L plate will reduce damage from dropping magazines on the ground.

Sounds more like a problem with the bolt carrier hold-open catch. Have you checked it for proper function, spring tension, burrs, binding? Does the bolt carrier fail to lock open on an empty GI mag when firing or when manually retracting the bolt carrier?

1DD

Definitely check this stuff out. But rebuilt the magazines anyway. They may be the only ones you'll ever have. Spend a little money and make them the best they can be.

My GOTO mag's were made in the 70`s !

For SD/HD I use the Colt 20rounders with alloy followers only.

I have refinished them once with SFL. Still using the same springs.

Sometimes the carrier wont lock back when using 223rem 77gr.

But always locks back when using 5.56mm loads.

Just clean the mag's when needed and add springs when needed.
Or if you use plastic followers you can change them when needed.


Really I prefer my Colt 20rounder w/ alloy followers over any mag out there.

The bolt carrier works fine on Magpul new mags, its just the old GI mags (that I have it fails on). I have a relatively new JP. Since I`m forced to compete in other states with these old GI 30 round mags It looks like I'm going become a GI mag mechanic. Other the other hand I can probably find an old Marine Armorer and bribe him with some spirits to refurbish my old GI mags.

In Mass if you look hard enough you can find some unused 30 rd mags in their original package (I saw some dated 1985) they go about $50 to $60 each. They are date stamped right on the mag Most folks here scarf them up for home defense, since if you shoot some one with a 30 rd mag you will go to the jail before the criminal if you did it with a 30 rder and you cannot prove its pre 1994,

thxs for the assistance

It might make more sense make friends with another competitor who can provide you with the needed mags at the event.



 

Date stamped preban mags are just a silly scam in Mass. It's the prosecutor's problem to prove it's postban and as long as your mag doesn't show signs of being too new they'd never get anything to stick. I slightly prefer dated mags since it makes it easier to answer casual questions, but if anything legal went down I wouldn't care one way or the other. Just buy undated prebans for $15-20 like everyone else.

Get new springs and followers for your mags. I wouldn't replace the floorplates since they should have preban markings on them.

Seriously couldn't you just stamp "1985" on it yourself??  Date stamps prove nothing, no mater who and when they were applied.

TheQuag whatever way it turns out hold on to the original follower, floorplate and spring for each mag and package/notate contents and type of mag.

       <Edited..........dpmmn>