I'm using the Hornady Lock-N-Load setup for my dies. I'm loading .38 and .357 shells and am crimping them with the seater die.

With that said, if I have the flaring die setup for .38, will I need to adjust it for .357 or can I run it as is?

How much flare you think you will give the 357 case @ 1.29” when you shove it into a flaring die set for proper function with a 38 case @ 1.155”.

Kind of what I was thinking. Just wanted to confirm.

You buy this washer set so you don't have to readjust your 38/357 dies. You adjust your dies for 38 and use the s57 washer for 357 cases.

https://www.midwayusa.com/product/1012401468?pid=189290

I had not seen the spacers before. Seems like a good idea. I may have to give them a try.

That washer is a neat tool. I've been looking to add some 38 dies to the collection. I saw lee gives you idea of how many turns to use but the washer seems a little more straight forward. From looking around it looks like just the washer is pretty backordered but seems like RCBS die sets also include them.

Yes RCBS includes them. Still wondering whether since it’s a Lock n Load if it’s more pain than gain. You would still have to remove the die from the quick lock, place the spacer in between. Doubt it would work between quick lock and press as it’s supposed to.

That is where I’m at. I went lock n load and it can be a pita

Option, if you are only worried about the flaring die, take a scratch awl scribe a line on the lock ring when setup for 38 special. On the die threads put a dab of nail polish lined up with the scribe, then set the die for 357 and put another scribe mark on the lock ring corresponding to the dab. You now have a rough in adjustment switching between the 2. Pain yes, but quick.
Other option is dedicated die set.