I went shopping for 00 buckshot ammunition for my newly acquired shotgun. I notice a difference of crimping. Some use a roll crimp that contains a solid cylindrical plastic plate. Some use a star crimp.

All ammunition I checked are high brass plastic cased. They both contain 12 00 buckshot pellets. I made a choice based on nothing in reality. My instinct favored the roll crimp ammunition, but I have no reason to believe it is superior in any way from star crimp. I chose the roll crimp even though Winchester and Federal ammunition is star crimped.

Why choose one crimp style be chosen over the other?

There is some evidence to suggest that the roll crimp produces less desirable groups than the star crimp in bird shot loads at 40 yards.

I can’t imagine a discernible difference with 00 buckshot.

You may find that the loaded roll crimp ammo is slightly longer than the star crimped ammo. This might make a difference in reliable functioning of your gun but, you’d have to test it to find out.

I’d probably buy the star crimp ammo if prices are comparable, otherwise I’d buy the cheapest.

No difference in crimp..unless you intend to reload the hulls.Then I'd get the star.

I would really be surprised if roll vs. crimp closure makes any meaningful difference in patterning. I once did a very extensive series of tests using a number of different 12 gauge shotguns (all of which had open chokes) with different 00 Buck loads (12 pellets). As I remember I did the tests at 15 yards. The differences in patterning performance between guns was unexpectedly large. Somewhere I have the results of a very similar test done at FLETC with very much the same results. If there is that much gun-to-gun patterning difference with 00B, it would far overshadow any small differences resulting from the type of shell closure used.

The style of crimp used for Buckshot from Zero to 15 yards is not your worry.
Getting the load on target is what counts in a SD moment!!

Your not using these for birds are you.........
and don't reload hulls for SD use.

Factory only, unless you have to use a "Uni Hull" as a last resort.