I seem to have trouble finding them. I ordered a 3 10 round mags with grey followers and I went down to the range. I didn't notice that one of them was a 10 round mag with an orange follower (bonus I suppose). Only, I went to load 10 rounds in the mag and it stopped at 5. So I popped the bottom off and noticed the spring was just a big coil with the expanded portion of the spring coincidentally elastic enough to handle 5 rounds. So now, I need to find some springs. Any idea where to get springs?
Might try some 30 round springs and cut them down to fit.... or contact Colt MFG as some states require 10 round mags...
The Colt 10 round AR mags sold many moons ago had an insert on top of the mag baseplate or under the follower (can't recall) that took up 10 rounds worth of space. Drill the rivet holding the baseplate in place, slide it off, remove the insert, reassemble the mag...voila! 20 round mag restored to full function. You might try a 20 round mag spring. They are available ($$$) from: Springs for COLT AR-15, CAR-15, M-16, M4, 9mm SMG AND SPORTER Rifles & Shotguns It would probably be even cheaper to just buy replacement 20 round mags, and steal a spring for your 10 round mag. See: C Products 20rd Gray Teflon AR15 Magazine NOTE: I'm not sure if the curved 20 round mag uses the same spring as a straight 20 round mag. Probably not.
I live in the police state of NY, where I can't get any mags over 10 capacity to modify...unless they're pre ban. I'll try cropping a 20 round spring
My condolences. I, on the other hand, live in the "free" state of Ohio. In OH, a non-.22 rimfire weapon with an installed mag of over ~31 round capacity is deemed a full auto weapon, even if it's semi-auto.
Could it be those 10s that hold only 5 are mags for hunting in (say) Massachusetts? F&G guys WILL check if you are out during the seasons.