The three point and single point are two different beasts, and serve two different purposes.  

The three point is more restrictive, and has issues regarding transition between shoulders.

The single point sling is less restrictive, and has no issue with raoid transitions to the support side.


I'll admit you have me lost on the bounce, swing and twist part.  I'm a city LEO (and instructor), and have carried a 3 point sling for years on my duty carbine.  Any of the above issues I've found with shooters have been shooter induced, and not part of any equipment issue if you are talking about continuity of fire.  If you are talking nonfiring, then yes, obviously the single point sling will move around if you take your hands off the weapon.  HOWEVER, the times when you are taking your hands off the weapon are limited to weapon trasnition, and in some cases handcuffing.  Proper transition is not an issue with a good SPS, but it is a training issue.  The methods used are pretty much the same as a three point, and there are 2 primary methods.  Handcuffing is similar.

LASTLY, the biggest thing to remember is that all single point slings are not the same.  Most are a basic loop around your torso with another loop that comes off.  I have tried numerous variations of these, and have ended up with a box full of garbage slings that serve no purpose.   This is why I stay using a 3 point for so long.  Eventually, the ASP Single Point Sling found its way to me, and I have been using it ever since.  Its my opinion based off military and LE time that there is no better single point sling available.  It doesn't sit the same as other single point slings, nor does it have all the faults that I disliked so strongly in the other single point slings.


Here is a quick picture of my basic gear.

What are the 2 purposes?

The role of the single point sling is a highly specialized one.

If you are looking for a sling used primarily in a CQB environment than there is a good chance
the single point sling is right for you. If weapon retention, cross shoulder transition, and high
speed transition from rifle to handgun are a top priority, the single point is your answer.

The role of the three point sling is a highly generalized one.

If you are looking for a sling to support the weight of your weapon for long intervals, the three
point is probably your answer. If cross shoulder transition isn't a concern (ie. shooting strong
side only), and keeping the weapon in a state of readiness, the three point is a decent choice.
However, most three point slings have a huge drawback. Complexity. There are even some on
the market that come with a large (many many page) manual and require the user to
assemble based on intended usage and purpose.

Regardless which sling type you choose, training is a requirement. Don't expect any tool to do
the work for you. You will need to spend time with it, train with it, in order to understand how
it functions.