Expanding bullets for the 9mm are considered to be poor choices for serious work in the 350L due to potential overexpansion problems (with resultant lack of penetration). I am pretty sure most expanding bullets intended for the 357 mag have the same potential overexpansion concern.
Many 0.358" rifle bullets are also considered poor choices for a couple of reasons. Risk of little or no expansion is one of the problems.
350L bullet size has been hashed and re-hashed. It would be nice if people who have no experience based knowledge would be patient and leave this question to those of us who have figured this out.
The vast majority of the 350L guns have a bore of 0.355". Yes, a traditional bullet (not solid copper) up to 0.358" is fine for being pushed through a 0.355" bore with no problems at all. Even though this is a nice factoid, it does not make much difference in this situation.
The problem is that the chamber dimensions on a high percentage of the guns out there in combination with and the typical brass wall thickness in the neck region combine to prevent the gun from properly chambering a round loaded with a regular bullet 0.357" or larger.
And like most things the above does have a few (probably more like very few) exceptions. Some guns have been found to have chamber necks big enough to use 0.357" bullets with most brass and some select brass has been identified that has a little bit thinner walls (early Starline, but it was found to have other problems in some guns).
For those really wanting to use 0.357" bullets, there are a couple of workable (but extra cost and effort) solutions.
Many 350L reloaders use regular 0.357 bullets but then run them through a Lee 0.356" push through bullet sizing die. They seem to chamber pretty good and there seems to be no adverse impact with respect to accuracy or terminal function.
Another solution for using 0.357" bullets would be to turn down the necks on your brass. Although this would be certain to work, I have not heard of anyone doing this.
A third solution would be to have the neck region of you chamber enlarged to provide an adequate clearance (0.002" or so). This would be tricky and not something for most do-it-yourself types and I doubt many gunsmiths would want to take this on given the potential problems if the job goes wrong.
Using 350L specific bullets will get you both the correct diameter and where applicable will get you a bullet tailored to expand properly at 350L velocities. Several bullet makers had jumped into the 350L game and came out with with new products that seemed to work quite well by those that were able to find them.
With good bullets (350L specific, or select 0.357"/0.358" sized down), even the AR folks were able to achieve results very close to the 357 Max. Those with 350L break open guns and some bolt action guns were able to get nearly identical results since they could load to about the same AOL. Note also that all 350L guns are rated at 55 ksi (I think) where the 357 Max is only rated 40 ksi (that few seem to pay any attention to).
If the great component shortage had not interrupted everything, plenty of 350L specific bullets would be readily available by now. All reloading supplies are about as easy to find as unobtainium right now. Start searching now for anything you hope to buy. Expect to look wide and far and be mostly disappointed.
FYI, If you just want to hunt without a lot of target shooting, higher priced bullets are worth considering. Maker bullets have a line of 350L solid copper bullets. Their 350L specific 180 gr is in stock at $38 for 50.
https://makerbullets.com/proddetail.php?prod=350LEGEND180REX
The 350L does have a downside. The fact that the 350L headspaces on the case mouth has created a lot of grief in certain situations. This can be tricky and there have been problems (notably even with some factory ammo).
There is a 350L group and a 350L reloading group on Facebook. Read back through the posts on these groups and you will find tons of real experience based reports on how effective the 350L has been and on how well reloading has worked out. The layout of these groups is however a PITA to weed through and as always, you have to assume a good percentage of what you read on the internet is shall we say "less than perfect" information.
https://www.facebook.com/groups/350Legend
https://www.facebook.com/groups/2237324616353981/?multi_permalinks=3684957181590710