When I bought my full auto Norrell 10/22, John Norrell also included an operations manual where he discussed his view on Ruger mags and repair. I have found it to be excellent and accurate.
From John Norrell's Ruger 10/22 Full Auto Operations Manual:
Section 5: MAGAZINES
Six brands or types of magazines will function properly in the Norrell full auto Ruger 10/22 and are listed in order of preference:
1. Standard Ruger Magazine (10 rounds). Always functions perfectly except when in rare cases when the spring is not wound tight enough by the manufacturer to feed rounds. Spring tension, however, can easily be tighten with an allen wrench.
2. Eagle (30 rounds) Available in black and smoke and are the best 30 round magazines ever made for the Ruger 10/22. The old style Eagle amber colored magazines are not reliable.
3. Butler Creek Steel Lips (25 round.) Stainless steel top piece with ejector located on the magazine. A good second choice in a high capacity magazine but only 25 rounds of firepower.
4. Ram-Line (30 round single column). Although discontinued in 1990, the following colors will function on full auto: All clear, one clear side and one black side, all smoke and all amber. The all black colored Ram-Line 30 round single column magazines did not function properly due to the type plastic used in the injection molding process. The amber magazines were the last to be made by Ram-Line in the single column design and were acceptable but borderline due to repairs needing to be made to the original molds.
5. Butler Creek Hot Lips (25 rounds). Does not have an ejector located on the magazine. Utilizes the secondary ejector in the firearm. Due to its delicate lip design, this particular magazine does not appear to be suitable for long term use.
6. Bingham Steel Magazine (30 rounds). Discontinued a number of years ago; however, it will function once fitted and fine tuned. This is the same type magazine as used in many .22 sub-caliber kits such as ones for the M-16, Mini-14, Thompson SMG, etc.
Magazines not recommended are listed below:
1. All black Ram-line 30 round single column
2. Amber Eagle 30 round single column
3. Ramline double feed column mags (all capacities and colors)
4. Sanford/Eaton 50 round drums
5. Mitchell 50 round tear drop drums
6. Eaton 25 round stick magazines
John also told me that the Condor mags (steel lip) are junk and won't feed reliably.