I probably would go via 1NT too, this isn't a clearcut decision to me.  But once partner shows a good two-suited hand with 3H, I think your hand looks better and is a maximum for your previous bidding so it is safe to bid 4S.

Well, this is definetely a hand made for resulting, looks like a loser in each suit to me. When opening a hand the distribution values are lower as there is no known fit, however once a fit is found then distribution values increase. ie: prior to fit 3v/2s/1doublton,  after fit found it becomes 5 void, 3 singleton, 1 for doubleton. The responder's hand  now can jump to eight points. So using same formula the opener's hand becomes a 20 pt hand. so that should be 28 combined. However the opening hand although it qualifies (rule of 20) as an opener can certainly not start dancing on table with the two singleton jacks. How many time can you count those points for the jack  Not once as far as Iam concerned. Personally I would not take much pride in putting down this five count as a constructive raise. If  partner can show me better than a minimum after 1nt forcing,  then I will share the good news.

The South hand is not worth a constructive raise.  I would bid 1N forcing.  With the North hand (I like 65 hands)  I would bid first 2H and over Souths 2S, bid 3H.

with 5hcp and a small stiff playing 2/1, 1nt a reasonable bid after partner opens [forcing 1 round],when partner rebids hearts showing at least a 5/4 distribution,i would look at 3 spades as a preference bid,not constructive.

BTW after thought,i thought if you have 6 card major,if responder bids 1nt "forcing" that in 2/1 you should rebid opening suit with very good 5[if you have nothing better to bid] or 6card suit.thats been my understanding.

Spade, the exception to that is a 4+ card heart suit, a very good 4 cd minor (say AKQx) or any 5cd minor.

rusty dont understand  your comment:

1. you open longer suit when you hold 2 suits, opening values[rule of 20 or better]

2.if open 6/4 or 6/5 my understanding is "must" rebid 6 card suit [unless no honors in it.]

3.by opening a 5/4 if bid higher ranking suit info to partner,is i have min of 5/4 or 5/5 in my bid suits,what is your perference.

4.wonder y you would open hearts when you hold 6 spades?

5.thought 1 is looking for a fit to reach best contract.

If you are 6 spades, 4+ hearts you open 1S and rebid 2H over the 1N forcing.

Or 3 or 4 hearts if your hand is good enough.  With the 6-5 shape here I think I would bid 3H even if there had been no interference.

interesting bid barton:

1.jump raise by opener =16-18

2.jump shift[no interference]=19-21

3.cue bid op bid suit  =game force

4.raise opening suit,think this a underbid

5.do a splinter c/d

 

with the above example hand,there is no way game should be missed