I got a new Saiga 12 a few weeks back and completed the conversion. The only problem I am having is FTF using Surefire mags. I have one 12 round mag that has not been modified and one 12 round that has been modified for use with the JT Surefire Magwell.
The factory unmodified Saiga five round mag functions with absolutly no problems with over 100 rounds fired using it.
The unmodified 12 rd. Surefire mag is not reliable with 2-3 FTF per mag. When I load the mag, the shells feel like they are catching on something in the mag. I have to work the shells up and down to get all shells load