Very nice!

So are they’re any spring i can buy that will work well without me having to buy extra parts?

No. It sounds like you have a reverse plunger unit. The best mod is a series of printed shims and putting in Retaliator internals.

Can you solder?

@torukmakto4 would have some experience with this, not sure how to tag them on here.

Length? OD?

I use generic 16/13mm alum parts of the desired length and then manually cut in a feed ramp with a tool.

What are we looking at? Is there a build log we can check out somewhere?