Hey guys, i've been wanting to get back into slinging pirouette but in past experiences my shoulder hasn't really been able to take it, any tips or ideas on how to solve this?

I definitely should've added a link to show the style in my first post, but here's the link: https://youtu.be/JSEqUMUzbZo
The style seems to pull my shoulder sort of backwards like a lever so after a small amount of slinging my shoulder will start to hurt similar to pulling a muscle. It could just be because I'm still new to the style so my shoulder hasn't warmed up to the motion yet but i really don't know. That isn't much but hopefully that cleared up some of it 

I'm in no position to give medical advice. You best ask a physiotherapist. But I have some understanding of sport injuries from two years of learning gymnastics.

This can strain your anterior deltoid muscle (or rotator cuff). It stretches your shoulder to the end range of motion and puts force on it. You have to do a warm up, like before any strength exercise.
If nothing else, at least do various arm circles, elbow circles, "dry-fire" without a stone and do this with your sling:
[url]https://www.youtube.com/watch?v=WyW5jGGxoZk[/url]
You can see how it prepares the shoulder for the backward lever pull you described.

When the throw starts hurting, stop doing it. It's injured already. Pushing over pain will not build it up! It will make it worse. It could be that, for example, it would heal in three days. But if you continue and do another few throws ignoring the pain, the shoulder won't heal fully in a week. Then, if you're too impatient and throw again next weekend, the annoying pain could come back on the first throw. When this happens, you realise you crappity smacked up. And that you won't sling pain-free for another few weeks, unless you finally give it a generous rest.

I've had this exact story happen with small wrist strains, and a lower back muscle overused by torso rotation when slinging.

there's actually no power to be gained from a one armed pirouette.

A sidearm with windup behind you has a lot more power as it lets you move the sling considerably faster.

You can spin  a by itself much faster than you can physically turn on the spot. If you have the technique to take that spin speed into the throw, then you generate a lot more power than is possible through a pirouette.

Thanks for all the advice, ill try and go through and reply to everything here:
Morphy & WojtekimbieR: I'm going to try out some new stretches that WojtekimbieR linked i certainly hope they'll help.
Parmenion: Part of me thought that the pain could be just because i'm new to the style and what you said made a lot of sense so i'll be sure to keep my shoulder in check.
Curious Aardvark: Yeah, i feel like all styles are about equal power-wise, i've just always wanted to learn how to sling pirouette accurately.
Thank you all for your great answers, i feel like i'll be able to figure out how to solve the pain once i go and sling