I was answering someone about this and I wrote this,
Let's look at the various narrations from Jundab bin Samura:
-Simak:
لَا يَزَالُ الْإِسْلَامُ عَزِيزًا إِلَى اثْنَيْ عَشَرَ خَلِيفَةً
"Islam shall remain strong until twelve caliphs."
-Ibn abi `Umar from `Abdul-Malik:
لَا يَزَالُ أَمْرُ النَّاسِ مَاضِيًا مَا وَلِيَهُمُ اثْنَا عَشَرَ رَجُلًا
"The people's affair shall be conducted well as long as they're led by twelve men."
-Ibn Mahdi from `Abdul-Malik:
لَا يَزَالُ هَذَا الْأَمْرُ صَالِحًا حَتَّى يَكُونَ اثْنَا عَشَرَ أَمِيرًا
"This matter shall remain good until twelve chiefs (rule)."
-Abu `Abdul-Samad from `Abdul-Malik:
لَا يَزَالُ هَذَا الدِّينُ عَزِيزًا أَوْ قَالَ لَا يَزَالُ النَّاسُ بِخَيْرٍ، شَكَّ أَبُو عَبْدِ الصَّمَدِ إِلَى اثْنَيْ عَشَرَ خَلِيفَةً
"This religion shall remain strong OR he said the people shall remain in goodness (the narrator was unsure) until twelve caliphs."
-Dawoud from Sha`bi:
لَا يَزَالُ هَذَا الْأَمْرُ عَزِيزًا إِلَى اثْنَيْ عَشَرَ خَلِيفَةً
"This matter shall remain strong until twelve caliphs"
-Mujalid from Sha`bi:
إِنَّ هَذَا الدِّينَ لَنْ يَزَالَ ظَاهِرًا عَلَى مَنْ نَاوَأَهُ، لَا يَضُرُّهُ مُخَالِفٌ وَلَا مُفَارِقٌ، حَتَّى يَمْضِيَ مِنْ أُمَّتِي اثْنَا عَشَرَ خَلِيفَةً
"This religion shall remain victorious over its opponents, unharmed by those who oppose it or leave it, until twelve caliphs from my nation come to pass."
-Ibn `Awn from Sha`bi:
لَا يَزَالُ هَذَا الدِّينُ عَزِيزًا مَنِيعًا إِلَى اثْنَيْ عَشَرَ خَلِيفَةً
"This religion shall remain strong and fortified until twelve caliphs."
-`Amir bin Sa`d:
لَا يَزَالُ الدِّينُ قَائِمًا حَتَّى تَقُومَ السَّاعَةُ أَوْ يَكُونَ عَلَيْكُمُ اثْنَا عَشَرَ خَلِيفَةً كُلُّهُمْ مِنْ قُرَيْشٍ
"The religion will remain to be upright until the hour or you are ruled by twelve caliphs all from Quraysh."
-Isma`il bin Hurmuz from Hurmuz:
لَا يَزَالُ هَذَا الدِّينُ قَائِمًا حَتَّى يَكُونَ عَلَيْكُمُ اثْنَا عَشَرَ خَلِيفَةً كُلُّهُمْ تَجْتَمِعُ عَلَيْهِ الْأُمَّةُ
"The religion will remain to be upright until you are ruled by twelve caliphs, the nation shall gather united around them."
-Fitr from Hurmuz:
لَا يَزَالُ هَذَا الْأَمْرُ مُؤَاتًي أَوْ مُقَارِبًا حَتَّى يَقُومَ اثْنَا عَشَرَ خَلِيفَةً
"This matter shall continue to be appropriate or adequate until the rule of twelve caliphs."
-Hosayn:
لا يَزَالُ هَذَا الدِّينُ قَائِمًا حَتَّى يَقُومَ اثْنَا عَشَرَ خَلِيفَةً
"The religion will continue to be upright until the rule of twelve caliphs."
-Musayyib:
إِنَّ هَذَا الأَمْرَ لا يَزَالُ ظَاهِرًا لا يَضُرُّهُ خِلافُ مَنْ خَالَفَهُ حَتَّى يُؤَمَّرَ اثْنَا عَشَرَ مِنْ أُمَّتِي كُلُّهُمْ مِنْ قُرَيْشٍ
"This matter will remain to be victorious, unharmed by the opposition of any opponent until twelve from my nation are granted authority, all of them from Quraysh."
That's pretty much all of the detailed narrations from Jabir aside from any summarized versions since those serve no purpose. We can clearly see what is meant by this narration, in that the condition of the religion will remain strong up until the rule of the first twelve caliphs, in other words it will remain good from the time of the Prophet (saw) and then keep weakening and deteriorating until by the time the twelfth passes, it's going to be a shell of its former self.
What you did is that you quoted the following:
It was narrated that Jaabir ibn Samurah said: I entered upon the Prophet (blessings and peace of Allah be upon him) with my father, and I heard him say: “This matter will not end until there have been among them twelve caliphs.” Then he said something that I could not hear, and I said to my father: What did he say? He said: “All of them will be from Quraysh.”
Narrated by al-Bukhaari (no. 7222); Muslim (no. 1821).
First of all, this text is not found in Bukhari like you claim, al-Bukhari narrates a summarized version without any context. Secondly, the text you quoted from Muslim is this one by Hosayn:
إِنَّ هَذَا الأَمْرَ لاَ يَنْقَضِي حَتَّى يَمْضِيَ فِيهِمُ اثْنَا عَشَرَ خَلِيفَةً
"This matter shall not come to pass until twelve caliphs rule them."
This is nothing more than a variation of the above texts as you can see by referring to Hosayn's text in the above list. The "Matter" here in this narration refers to the strength of the religion, its resilience and glory shall not diminish until the Muslims are ruled by twelve caliphs.
The prophesy was fulfilled, we were ruled by twelve from Quraysh and religion weakened gradually. Nothing can be concluded from the above that we will ONLY have 12 leaders and then the world will end, that is a very corrupt interpretation on your part. Proof is that we were ruled by plenty of Caliphs and nothing ended.