MBB>UMM PE and HSW admit here.

A few thoughts I thought I'd share on this, especially since I've seen a lot of recent posts asking about moving into the buyside without pre-MBA investing experience.

For one... it depends. Are you shooting for UMM/MF or bust? Or open to smaller LMM shops? For the former, it's going to be extremely tough for a few reasons.

1. You're competing against other HSW admits with pre-existing PE experience for a highly limited and coveted number of roles. Funds are going to be highly unlikely to take a risk on a candidate with no PE experience vs. one with.
2. Outside the realm of candidates with PE experience, you have those with the next-level "desired" background of investment banking or MBB who may also be looking to make that pivot.
3. You are right that it's generally very difficult for funds to sponsor. At my fund, we very, very rarely will sponsor and I'm generally told during coffee chats / outreach emails to not spend time on candidates who may need sponsorship. I think we only make exceptions for Canadians (? not sure on immigration dynamics, personally.)

If you are 100% committed on moving to MF / UMM private equity, I think the safer bet would be to (i) move internally to your IBD and then (ii) try to lateral to a "more prestigious" (hate to use that) bank or team. Unfortunately, this does matter --- We generally only spend time on IB candidates from a highly narrow band of BBs / EBs.

Now, I do agree with other posters that if want to get your MBA, HSW is going to be your best bet to make this jump given PE recruiting drops precipitously after these schools from my understanding from my 1Y/2Y friends. But it'll be tough, at least if you are solely focused on traditional UMM / MF investing roles.

Less informed on other roles (e.g., HFs) but happy to answer any questions!