I have a unique question that I have not seen the answer to. I own both a G20SF and G29SF and have various conversion barrels for them. Yesterday I ordered a G33 and should have it in my hands early next week. This got me thinking... what difference is there between the large frame Glock barrels compared to the small frame Glock barrels (aside from caliber and length)? In other words, if I had a G31, would my G20 barrel fit in the G31 slide? Specifically, would a G20 10mm->.357 Sig conversion barrel fit/work in the G31? What about the same question with the compacts? How does the barrel/slide fitment on a G33 compare to the G29?