Yes Bill Ruger Sr. was an early advocate of a ban on magazines having more than 10 round capacity. In 1989 he wrote to Congress advocating this...
"The best way to address the firepower concern is therefore not to try to outlaw or license many millions of older and perfectly legitimate firearms (which would be a licensing effort of staggering proportions) but to prohibit the possession of high capacity magazines. By a simple, complete, and unequivocal ban on large capacity magazines, all the difficulty of defining "assault rifles" and "semi-automatic rifles" is eliminated. The large capacity magazine itself, separate or attached to the firearm, becomes the prohibited item. A single amendment to Federal firearms laws could prohibit their possession or sale and would effectively implement these objectives."
In addition to the furor amongst hunters, sportsmen and shooters caused by "The Ruger Letter", Ruger made additional comments during an interview with NBC's Tom Brokaw that angered 2nd Amendment proponents even further, saying that "no honest man needs more than 10 rounds in any gun…" and "I never meant for simple civilians to have my 20 and 30 round magazines…"
The above is taken from the wikipedia article on Ruger. Ruger was one of the architects of what became known as the Clinton Ban which was enacted in 1994 IIRC. Ruger's position on this was quite thought out and in no way a "slip of the lip". He was one of those who developed the idea of it and advocated for it. He began this prior to Clinton's election. All this was some time back.
tipoc
