Need help - 20 round AR-15 mag question.

[Big Frank]

Can someone please tell me how many coils are on a GI 20 round AR-15 mag spring? I put Magpul Enhanced Self-Leveling Follower – USGI 5.56x45 in my 20 round mags and they only held 15 rounds or so before I cut them down. I don't remember how many, but I could put unmodified followers from my GI 30 round mags in if anyone wants to know how many they'll hold. Yesterday I cut them down even farther and put the followers and 20 rounds in each mag without the springs. When I assembled the mags, they would barely hold 19 rounds and were so tight I took one round out. The mag springs I bought may actually be for 30 round mags but worked fine when the mags were limited to 5 rounds, with black followers, and when I stuck green anti-tilt GI followers in. The green followers also limited the mags some without 5 round limiters. I just want to be able to load the full 20 rounds without using the black followers that make the rounds nose-dive and jam.

[Big Frank]

If anyone has 20 round and 30 round mags of the same brand, like Magpul, if you count the coils on both springs I can count the coils on a 30 round GI mag spring and extrapolate from there. If a 20 has 2/3 or 3/4 as as many coils as a 30, then these probably should too. They're 10% extra power Chrome Silicon round wire springs from Tubb Precision that used to come in 20, 30, and 40 round versions. But now they only sell 17-7 stainless steel flatwire magazine springs for 30 round mags. They don't even know how many coils were on the old springs, so I don't know if I had 30 round springs in 20 round packages.

[Big Frank]

I just read this at Tubb's site: Note: Due to the flatwire design our 30 rd magazine spring, it will also fit into US GI 20 round magazines. So, if anyone else has 20 round mags they want to put new springs in, those will work, but the the springs I already have are made to last a lifetime. One spring is $13.95, a 3 Pack is $29.95, and a 5 Pack is $45.95. Instead of buying 2 for $27.90, I would get the 3 Pack if I bought them at all. The 3rd spring would only cost $2.05, and I could use it in a 30 round mag if a spring ever went bad. The precipitation hardened 17-7 stainless steel flatwire springs should outlast the life of the magazine, or the shooter.

https://www.davidtubb.com/ar15-tubb-parts

[Big Frank]

Anybody? I guess I can just cut off a coil at a time until all 20 rounds fit.

[Majer]

Sorry Frank,
we're not allowed over a 10 round magazine in the peoples democratic republic of newyorkistan.

[Sponsor]

[Big Frank]

Well, that sucks, Majer. I'm sure you have a reason to be there, but I don't think I could live there. I don't own any mags over 110 rounds. My 2 biggest AR mags are 100, and 60 rounds. The 110 rounder is for my 10/22. I'm planning on finally trying it out this summer.

[Big Frank]

I cut one coil off one magazine spring and was barely able to force 20 rounds in, but it was so tight I knew it wouldn't seat with a closed bolt. So I cut 2 coils off the other mag spring and 1 more off that one. It helped, but barely. I had Magpul Ranger Plates on both mags. They're a 2-piece design. The main part slips onto the 4 hooks on the bottom of the mag just like a G.I. floor plate, but the retainer intrudes into the magazine, so I took them off and put flat metal floorplates back on. It gave me just a little bit of room when I pressed down hard on the top round. But now the springs feel too weak and I don't think they'll work. And I can only seat the mags if I pound them in. I'm going to order the flatwire springs from David Tubb, and I think I have to take the Magpul followers out. I don't want to use the original black followers. Instead, I'll cut the center stem and front leg off the bottom of the green anti-tilt followers that limits their travel. I have 9 of those since the Magpul followers fit 30-round mags and I swapped them out. The old black followers don't have a front leg at all, so even if I cut half of it off, it has to be an improvement. Under the best circumstances, the tips of the bullets only clear the front of the mag by thousandths of an inch, so if the follower tips down it won't feed at all. The Magpul followers are a little bit thicker than the black or green ones, so I should cut a couple of green ones down while I wait for my new springs.

The magazine followers in the pictures are Blue - OKAY Industries SureFeed E2, Dark Green - Magpul  Enhanced Self-Leveling Follower - USGI, Light Green, G.I. anti-tilt follower, Black - original Colt follower from a 20-round mag. The old G.I. 30-round followers were black and looked like the anti-tilt follower without its front leg. They had the center post that the 20-round followers lack, so they were halfway in between those two in terms of what was sticking down. The first round you load in the SureFeed E2 mag will be on the right side, and it will be on the left side in all the other mags. Don't ask why, because I haven't the foggiest idea.

https://magpul.com/rangerplate-usgi5-56x45-3pack.html?mp_global_color=118

P.S. The Magpul Ranger Plates don't have those 2 things sticking way up on the sides. They have the wrong picture on their site. That has to be for PMAGs. It's the next picture they show.

[Big Frank]

I cut these 2 followers down even shorter, until the magazines without a spring in them would each hold 20 hounds and not 21. But when I put the Tubb flatwire springs in, I only got 18 rounds in one mag and 17 in the other. I'm going to buy new followers and throw these in the trash. I'll see what the capacity is with whole followers and 30-round springs that are also supposed to work in 20-round mags. I may have to cut some coils off, but maybe not. It depends on how bad the result is without cutting them. I took apart my 30-round mags that I replaced the followers in and found 2 that I forgot about shortening the followers in an earlier experiment with the 20-round mags. They come in 3-packs, and I need 4 of them, so I have to buy 2 packages. Magpul didn't have the foliage green ones in stock for awhile but they do now. I could have bought some yellow followers before, but thought I'd stick to one color.