If you remember the origin of Naruto's trouble on controlling chakra was the seal placed on him to seal Kurama and keep it under control.
Jiraya said so during their training when Naruto was learning Rasengan back in the days.
This was also the reason why in academy Naruto always sucked at chakra control.
The reason why he know can make base Rasengan without clones doesn't have to do with Sage Mode and only indirectly to do with BM. Since he befriended Kurama he has ripped the seal of Kurama's cage and effectively open the lock, in other words the seal is no longer active and he is now holding Kurama like any other Jinshuriki (without seals).
So if the seal is no longer a problem there is no reason why he wouldn't be able to control chakra as well as anyone else.
In fact if we take into account that since he has learned Rasengan, Naruto has made literally tens of thousands of them, with loads of clones making dozens of Rasengans at the same time. Each time a clone made a Rasengan and then disappeared the original Naruto would gain more experience at making Rasengans, which makes him extremely experienced in that.
Now every single one of those Rasengans were made while under the influence of the seal constriction, which made them so hard to do that Naruto had to use two clones to make it.
So putting it into simple words Naruto not only has done tens of thousands of Rasengans he has also made those Rasengans under extreme chakra control restriction, and he accumulated all that knowledge and experience.
Obviously now that the seal is gone so is the restriction making it that much easy to Naruto.
A good example of how Naruto has gained mastery over Rasengan chapters ago is this:
So there you go, at this stage Naruto making a one hand Rasengan should be absolutely no surprise. He has displayed far more chakra control capabilities than anyone else on the manga. And the only reason why he was being pulled down regarding chakra control is not a factor anymore since he befriended Kurama.
Hope this was enlightening for those of you who were wondering.
Jiraya said so during their training when Naruto was learning Rasengan back in the days.
This was also the reason why in academy Naruto always sucked at chakra control.
The reason why he know can make base Rasengan without clones doesn't have to do with Sage Mode and only indirectly to do with BM. Since he befriended Kurama he has ripped the seal of Kurama's cage and effectively open the lock, in other words the seal is no longer active and he is now holding Kurama like any other Jinshuriki (without seals).
So if the seal is no longer a problem there is no reason why he wouldn't be able to control chakra as well as anyone else.
In fact if we take into account that since he has learned Rasengan, Naruto has made literally tens of thousands of them, with loads of clones making dozens of Rasengans at the same time. Each time a clone made a Rasengan and then disappeared the original Naruto would gain more experience at making Rasengans, which makes him extremely experienced in that.
Now every single one of those Rasengans were made while under the influence of the seal constriction, which made them so hard to do that Naruto had to use two clones to make it.
So putting it into simple words Naruto not only has done tens of thousands of Rasengans he has also made those Rasengans under extreme chakra control restriction, and he accumulated all that knowledge and experience.
Obviously now that the seal is gone so is the restriction making it that much easy to Naruto.
A good example of how Naruto has gained mastery over Rasengan chapters ago is this:
The first time Naruto used Rasengan Shuriken in battle was against Kakuso (chapter #339)
As you can see, he needed two clones helping him, which is the equivalent of six hands.
The first clone was obviously to aid in the Rasengan making as for the secound clone was there adding the Futton chakra, while the original Naruto was keeping the chakra tight together.
In KCM already during the War Ark (chapter 545) Naruto makes a mini Rasengan Shuriken
On the making of this he used only the equivalent of two people, his finger keeping the chakra together while the two mini hands are adding both rotation and Futton to the jutso.
Although to be honest he might even go further and say that he was only using three hands. One to make the Rasengan* (finger) and the other two to add the Futton. And I say this because at this time he was not having Kurama's help controlling anything, each of those hands are being directly controlled by one Naruto.
This is a clear proof that Naruto has no problem regarding what goes into perfect chakra control.
*I say one hand/finger to make the Rasengan because of several examples:
#1
On the first panel Naruto makes a giant Rasengan with only one hand and uses chakra hands to bring the target towards his Rasengan
#2
Here (on the first panel), Naruto makes several Rasengans at the same time using only two hands
Then (on the 2nd panel), much like Obito is doing now with his OnMyYoudon spheres, Naruto keeps those Rasengans floating on his back, which shows complete and absolute ability to keep them all spinning and compressed. Again I remind you that Kurama is not helping yet, this is all Naruto's chakra control.
And Finally on the major panel (the third one), Naruto takes those Rasengans and without loosing control over neither the spin nor the compression he is able to control several hands independently to grab the Rasengans and direct them to their targets.
Again all of this without Kurama's help and with the seal very much active.
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As you can see, he needed two clones helping him, which is the equivalent of six hands.
The first clone was obviously to aid in the Rasengan making as for the secound clone was there adding the Futton chakra, while the original Naruto was keeping the chakra tight together.
In KCM already during the War Ark (chapter 545) Naruto makes a mini Rasengan Shuriken
You must be registered for see images
On the making of this he used only the equivalent of two people, his finger keeping the chakra together while the two mini hands are adding both rotation and Futton to the jutso.
Although to be honest he might even go further and say that he was only using three hands. One to make the Rasengan* (finger) and the other two to add the Futton. And I say this because at this time he was not having Kurama's help controlling anything, each of those hands are being directly controlled by one Naruto.
This is a clear proof that Naruto has no problem regarding what goes into perfect chakra control.
*I say one hand/finger to make the Rasengan because of several examples:
#1
You must be registered for see images
On the first panel Naruto makes a giant Rasengan with only one hand and uses chakra hands to bring the target towards his Rasengan
#2
You must be registered for see images
Here (on the first panel), Naruto makes several Rasengans at the same time using only two hands
Then (on the 2nd panel), much like Obito is doing now with his OnMyYoudon spheres, Naruto keeps those Rasengans floating on his back, which shows complete and absolute ability to keep them all spinning and compressed. Again I remind you that Kurama is not helping yet, this is all Naruto's chakra control.
And Finally on the major panel (the third one), Naruto takes those Rasengans and without loosing control over neither the spin nor the compression he is able to control several hands independently to grab the Rasengans and direct them to their targets.
Again all of this without Kurama's help and with the seal very much active.
So there you go, at this stage Naruto making a one hand Rasengan should be absolutely no surprise. He has displayed far more chakra control capabilities than anyone else on the manga. And the only reason why he was being pulled down regarding chakra control is not a factor anymore since he befriended Kurama.
Hope this was enlightening for those of you who were wondering.
