Maybe you can help me out here, isnt Luthers teaching one of 'co or consubstatiation'? and not transubstantiation?
I'll let Luther speak for himself as to what he teaches regarding the body and blood of Christ in the Sacrament:
What is the Sacrament of the Altar?
It is the true body and blood of our Lord Jesus Christ under the bread and wine, instituted by Christ Himself for us Christians to eat and to drink.
--Small Catechism: The Sacrament of the Altar
Or similarly:
Now, what is the Sacrament of the Altar?
Answer: It is the true body and blood of our Lord Jesus Christ, in and under the bread and wine which we Christians are commanded by the Word of Christ to eat and to drink. And as we have said of Baptism that it is not simple water, so here also we say the Sacrament is bread and wine, but not mere bread and wine, such as are ordinarily served at the table, but bread and wine comprehended in, and connected with, the Word of God.
It is the Word (I say) which makes and distinguishes this Sacrament, so that it is not mere bread and wine, but is, and is called, the body and blood of Christ. For it is said: Accedat verbum ad elementum, et fit sacramentum. If the Word be joined to the element, it becomes a Sacrament. This saying of St. Augustine is so properly and so well put that he has scarcely said anything better. The Word must make a Sacrament of the element, else it remains a mere element. Now, it is not the word or ordinance of a prince or emperor, but of the sublime Majesty, at whose feet all creatures should fall, and affirm it is as He says, and accept it with all reverence, fear, and humility.
With this Word you can strengthen your conscience and say: If a hundred thousand devils, together with all fanatics, should rush forward, crying, How can bread and wine be the body and blood of Christ? etc., I know that all spirits and scholars together are not as wise as is the Divine Majesty in His little finger. Now here stands the Word of Christ: Take, eat; this is My body; Drink ye all of it; this is the new testament in My blood, etc. Here we abide, and would like to see those who will constitute themselves His masters, and make it different from what He has spoken. It is true, indeed, that if you take away the Word or regard it without the words, you have nothing but mere bread and wine. But if the words remain with them, as they shall and must, then, in virtue of the same, it is truly the body and blood of Christ. For as the lips of Christ say and speak, so it is, as He can never lie or deceive.
--Large Catechism: The Sacrament of the Altar, 8-14
Now, Cap'n, as to "consubtantiation": I presume you mean by that Aristotelian, philosophical term (Lutherans tend not to use the language of "consubstantiation," "transubstantiation," "substance" and "accidents") the fact that Luther says, "under the bread and wine" or "in and under the bread and wine." But note that that is not the main thing in this sacrament. The big deal, and the thing that Luther emphasizes, is that it is the body and blood of Christ!
As to the medieval Roman teaching of transubstantiation, I will let the "Second Martin," Martin Chemnitz (1522-86), address that one:
Is the bread changed into the body of Christ, so that it altogether loses its own substance?
The particular character of this Sacrament requires that there be two distinct things or substances which, joined by sacramental union, make one complete Sacrament, even as in the one person of Christ there are two complete and distinct natures. For all antiquity uses this comparison. But Paul mentions bread and wine also after the blessing, 1 Co 10:16; 11:27. Likewise the fathers also taught the same. In order to testify that they do not approve the papistic transubstantiation, they also usually used these terms, namely that in, with, and under the bread and wine the body and blood of Christ are present, offered, and received.
--Martin Chemnitz, Ministry, Word, and Sacraments: An Enchiridion (Translation published by Concordia Publishing House, 1981)
Out of curiosity, are there any Eucharistic miracles in the Lutheran Church?