I am absolutely suggesting that. It's revisionist to claim otherwise. They implemented socialism with the aim of eventually bringing about communism, in line with historical materialism and dialectical materialism. But you need a few generations of socialism (and possibly Permanent Revolution rather than Comminusm in One Country, which was the big feud between Stalin and Trotsky, for example) before you could possibly transition to communism.
Oh, and hey: many people do claim that the USSR wasn't actually _socialist_. You'll find two groups who do this: anarchists, and new Marxists who still have some liberal left in them. The USSR certainly claimed to be socialist, and was according to socialist principles.
The two groups will make this incorrect, revisionist claim because of two reasons. Anarchists want to bolster socialism while trashing statism, so they want to play up 'state socialism's failures. New Marxists will want to play down any perceived 'failures' of Marxism by distancing themselves from said 'failures.'
You omitted those who consider that there are different forms of socialism. Bertrand Russell covers this ground in "The Practice and Theory of Bolshevism" (which you'll find on Project Gutenberg). Since he was writing in the 1920s I don't think it can be considered too revisionist.
Suggested reading material would be welcome. I have a reading list of economic and political philosophy I'm plowing through in roughly chronological order, but I'm only up to mid-19th century so far.
If you only want one book, that book is Capital I. I suggest David Harvey's lectures along with it, they'll help out quite a bit. If you have read Smith and Ricardo, that'll make it much easier, too. For bonus points, read the short "Wages, price, and profit" by Marx, it's a bit easier of an intro than the book's.
If you can fit in a second, I'd suggest "the State and Revolution" by Lenin.
Marx identifies a problem and a crude solution, and Lenin provides a good solution. Those two will give you the most of it. Wikipedia, especially on the historical/dialectical materialism stuff, is helpful.
My knowledge of Soviet history is incomplete, but surely you're not suggesting that the USSR didn't claim to implement communism.