These are the most inaccurate slugs I've ever used. I tried to group them in two different RIA VRPA40s, two different SuperNOVAs, and two different 590A1s...all with iron sights......results were all the same, my groups were anywhere from about 12-24" at 25 yards, with no rime or reason....I have no confidence in these past maybe 15 yards. I cut one open and it's got a 375 grain Foster slug that has four "rifle" grooves every 90 degrees. Not sure what the issue is with these but same range sessions with same shotguns using Winchester Ranger low recoil and reloaded Lee Key Drive Key 1 oz slugs at the same distances returned groups of 1" to 3"..so it's not the shotguns and it's not me. Continuing to research.