I use the RCBS drop tube (~4") with the swirl charge technique too! I started using that method to avoid compressed loads on other guns. I use a 22 cal insert for all calibers. I figured the 22 cal would slow the fill process and be helpful. I'm now wondering if I should try a matching insert for the caliber. Maybe the 22 call in the 6.5 SAUM case is too small a diameter vs. the case width. Just spit balling trying to come up with something else to try.